Scouting Charts – Canola and Flax

Reminder – One last time for this growing season….. We have updated the field scouting charts so they now link to pages within the 2018 version of the Insect Field Guide

We offer TWO generalized insect pest scouting charts to aid in-field scouting on the Canadian prairies:

1. CANOLA INSECT SCOUTING CHART

2018_ScoutingChart_Canola

2. FLAX INSECT SCOUTING CHART

2018_ScoutingChart_Flax

These charts feature hyperlinks directing growers to downloadable PDF pages within the “Field crop and forage pests and their natural enemies in western Canada: Identification and management field guide“.

Whenever possible, monitor and compare pest densities to established economic or action thresholds to protect and preserve pollinators and beneficial arthropods. Economic thresholds, by definition, help growers avoid crop losses related to insect pest species but they rely on in-field scouting!

Pea leaf weevil

Pea Leaf Weevil (Sitona lineatus– Model runs for Red Deer and Saskatoon were projected to June 30, 2019. Results indicated that oviposition is well underway at both locations.  

Figure 1. Predicted status of pea leaf weevil populations near Red Deer AB projected to June 30, 2019, using long term average temperatures.
Figure 2.  Predicted status of pea leaf weevil populations near Saskatoon SK projected to June 30, 2019, using long term average temperatures.

This week, pea leaf weevil and its doppelgangers were featured as part of the INSECT OF THE WEEK.  

Adults will feed upon the leaf margins and growing points of legume seedlings (alfalfa, clover, dry beans, faba beans, peas) and produce a characteristic, scalloped (notched) edge.  Females lay 1000 to 1500 eggs in the soil either near or on developing pea or faba bean plants from May to June.

Biological and monitoring information related to pea leaf weevil in field crops is posted by the province of Alberta and in the PPMN monitoring protocol.

Also refer to the pea leaf weevil page within the “Field Crop and Forage Pests and their Natural Enemies in Western Canada: Identification and management field guide” – both English-enhanced or French-enhanced versions are available.  A review of this insect was published in 2011 in Prairie Soils and Crops by Carcamo and Vankosky.

Pea leaf weevil

Pea Leaf Weevil (Sitona lineatus– Model runs for Red Deer AB (Fig. 1) and Swift Current SK (Fig. 2) were projected to June 15, 2019. Results indicated that oviposition should begin early next week. Model predictions, based on long term normal weather data predict that initial hatch near Saskatoon should occur on May 29th.

Figure 1. Projected predicted status of pea leaf weevil populations near Red Deer AB to
June 15, 2019 using long term average temperatures.
Figure 2. Projected predicted status of pea leaf weevil populations near Swift Current SK to
June 15, 2019 using long term average temperatures.

Pea leaf weevils emerge in the spring primarily by flying (at temperatures above 17ºC) or they may walk short distances. Pea leaf weevil movement into peas and faba beans is achieved primarily through flight.  Adults are slender, greyish-brown measuring approximately 5 mm in length (Fig. 3, Left).  

The pea leaf weevil resembles the sweet clover weevil (Sitona cylindricollis) but the former is distinguished by three light-coloured stripes extending length-wise down thorax and sometimes the abdomen.  All species of Sitona, including the pea leaf weevil, have a short snout.  

Figure 3.  Comparison images and descriptions of four Sitona species adults including pea leaf weevil (Left).

Adults will feed upon the leaf margins and growing points of legume seedlings (alfalfa, clover, dry beans, faba beans, peas) and produce a characteristic, scalloped (notched) edge.  Females lay 1000 to 1500 eggs in the soil either near or on developing pea or faba bean plants from May to June.

Biological and monitoring information related to pea leaf weevil in field crops is posted by the province of Alberta and in the PPMN monitoring protocol.

Also refer to the pea leaf weevil page within the “Field Crop and Forage Pests and their Natural Enemies in Western Canada: Identification and management field guide” – both English-enhanced or French-enhanced versions are available.  A review of this insect was published in 2011 in Prairie Soils and Crops by Carcamo and Vankosky.

Pea leaf weevil

Pea Leaf Weevil (Sitona lineatus– Model runs for Red Deer AB (Fig. 1) and Swift Current SK (Fig. 2) were projected to June 15, 2019. Results indicated that oviposition should begin at the end of May. Model predictions, based on long term normal weather data, predict that initial hatch near Saskatoon should occur on May 29th.

Figure 1.  Projected predicted status of pea leaf weevil populations near Red Deer AB to June 15, 2019 using long term average temperatures.
Figure 2.  Projected predicted status of pea leaf weevil populations near Swift Current SK to June 15, 2019 using long term average temperatures.

Pea leaf weevils emerge in the spring primarily by flying (at temperatures above 17ºC) or they may walk short distances. Pea leaf weevil movement into peas and faba beans is achieved primarily through flight.  Adults are slender, greyish-brown measuring approximately 5 mm in length (Fig. 3, Left).  

The pea leaf weevil resembles the sweet clover weevil (Sitona cylindricollis) but the former is distinguished by three light-coloured stripes extending length-wise down thorax and sometimes the abdomen.  All species of Sitona, including the pea leaf weevil, have a short snout.  

Figure 3.  Comparison images and descriptions of four Sitona species adults including pea leaf weevil (Left).

Adults will feed upon the leaf margins and growing points of legume seedlings (alfalfa, clover, dry beans, faba beans, peas) and produce a characteristic, scalloped (notched) edge.  Females lay 1000 to 1500 eggs in the soil either near or on developing pea or faba bean plants from May to June.

Biological and monitoring information related to pea leaf weevil in field crops is posted by the province of Alberta and in the PPMN monitoring protocol.

Also refer to the pea leaf weevil page within the “Field Crop and Forage Pests and their Natural Enemies in Western Canada: Identification and management field guide” – both English-enhanced or French-enhanced versions are available.  A review of this insect was published in 2011 in Prairie Soils and Crops by Carcamo and Vankosky.

Flea beetles

Flea Beetles (Chrysomelidae: Phyllotreta species)– As newly seeded stands begin to emerge, the need for in-field scouting increases.  Review Wk05 for flea beetle information, visual guides to help estimate percent of cotyledon damage, and links to the Insect Field Guide.  

This week we also link to Canola Watch which released flea beetle scouting and management tips for canola.  Provincial entomologists, flea beetle researchers and Canola Council of Canada specialists all provided input into this article.

Remember, the Action Threshold for flea beetles on canola is 25% of cotyledon leaf area consumed.  Watch for shot-hole feeding in seedling canola but also watch the growing point and stems of seedlings which are particularly vulnerable to flea beetle feeding.

Pea leaf weevil

Pea Leaf Weevil (Sitona lineatus– Model runs for Red Deer AB (Fig. 1) and Swift Current SK (Fig. 2) were projected to June 15, 2019. Results indicated that oviposition should begin at the end of May. Model predictions, based on long term normal weather data, predict that initial hatch near Saskatoon should occur on May 29th.

Figure 1.  Projected predicted status of pea leaf weevil populations near Red Deer AB to June 15, 2019 using long term average temperatures.
Figure 2.  Projected predicted status of pea leaf weevil populations near Swift Current SK to June 15, 2019 using long term average temperatures.

Pea leaf weevils emerge in the spring primarily by flying (at temperatures above 17ºC) or they may walk short distances. Pea leaf weevil movement into peas and faba beans is achieved primarily through flight.  Adults are slender, greyish-brown measuring approximately 5 mm in length (Fig. 3, Left).  

The pea leaf weevil resembles the sweet clover weevil (Sitona cylindricollis) but the former is distinguished by three light-coloured stripes extending length-wise down thorax and sometimes the abdomen.  All species of Sitona, including the pea leaf weevil, have a short snout.  

Figure 3.  Comparison images and descriptions of four Sitona species adults including pea leaf weevil (Left).

Adults will feed upon the leaf margins and growing points of legume seedlings (alfalfa, clover, dry beans, faba beans, peas) and produce a characteristic, scalloped (notched) edge.  Females lay 1000 to 1500 eggs in the soil either near or on developing pea or faba bean plants from May to June.

Biological and monitoring information related to pea leaf weevil in field crops is posted by the province of Alberta and in the PPMN monitoring protocol.

Also refer to the pea leaf weevil page within the “Field Crop and Forage Pests and their Natural Enemies in Western Canada: Identification and management field guide” – both English-enhanced or French-enhanced versions are available.  A review of this insect was published in 2011 in Prairie Soils and Crops by Carcamo and Vankosky.

Scouting Charts – Canola and Flax

Reminder – We have updated the field scouting charts so they now link to pages within the 2018 version of the Insect Field Guide

We offer TWO generalized insect pest scouting charts to aid in-field scouting on the Canadian prairies:

1. CANOLA INSECT SCOUTING CHART

2018_ScoutingChart_Canola

2. FLAX INSECT SCOUTING CHART

2018_ScoutingChart_Flax

These charts feature hyperlinks directing growers to downloadable PDF pages within the “Field crop and forage pests and their natural enemies in western Canada: Identification and management field guide“.

Whenever possible, monitor and compare pest densities to established economic or action thresholds to protect and preserve pollinators and beneficial arthropods. Economic thresholds, by definition, help growers avoid crop losses related to outbreaking insect pest species.

Good luck with your scouting!

Flea beetles

Flea Beetles (Chrysomelidae: Phyllotreta species)– Reminder – Be on the lookout for flea beetle damage resulting from feeding on canola cotyledons but also on the stem.  Two species, Phyllotreta striolata and P. cruciferae, will feed on all cruciferous plants but they can cause economic levels of damage in canola during the seedling stages.

Remember, the Action Threshold for flea beetles on canola is 25% of cotyledon leaf area consumed.  Watch for shot-hole feeding in seedling canola but also watch the growing point and stems of seedlings which are particularly vulnerable to flea beetle feeding.

Estimating flea beetle feeding damage can be challenging.  Using a visual guide to estimate damage can be helpful.  Canola Watch circulated this article but also use the two images (copied below for reference) produced by Dr. J. Soroka (AAFC-Saskatoon)  – take it scouting!

Figure 1. Canola cotyledons with various percentages of leaf area consume owing to flea beetle feeding damage (Photo: Soroka & Underwood, AAFC-Saskatoon).
Figure 2.  Percent leaf area consumed by flea beetles feeding on canola seedlings (Photo: Soroka & Underwood, AAFC-Saskatoon).

Refer to the flea beetle page from the “Field Crop and Forage Pests and their Natural Enemies in Western Canada: Identification and management field guide” as an English-enhanced or French-enhanced version.

Pea leaf weevil

Pea Leaf Weevil (Sitona lineatus– The PLW model was run for Red Deer AB (Fig. 1) and Saskatoon SK (Fig. 2). The predictive model outputs suggest that PLW adults are active but oviposition has not begun. 

Figure 1. Predicted status of pea leaf weevil populations near Red Deer as of  May 7, 2019. 
Figure 2. Predicted status of pea leaf weevil populations near Saskatoon SK as of May 7, 2019.

Pea leaf weevils emerge in the spring primarily by flying (at temperatures above 17ºC) or they may walk short distances. Pea leaf weevil movement into peas and faba beans is achieved primarily through flight.  Adults are slender, greyish-brown measuring approximately 5 mm in length (Fig. 3, Left).  

The pea leaf weevil resembles the sweet clover weevil (Sitona cylindricollis) but the former is distinguished by three light-coloured stripes extending length-wise down thorax and sometimes the abdomen.  All species of Sitona, including the pea leaf weevil, have a short snout.  

Figure 3.  Comparison images and descriptions of four Sitona species adults including pea leaf weevil (Left).

Adults will feed upon the leaf margins and growing points of legume seedlings (alfalfa, clover, dry beans, faba beans, peas) and produce a characteristic, scalloped (notched) edge.  Females lay 1000 to 1500 eggs in the soil either near or on developing pea or faba bean plants from May to June.

Biological and monitoring information related to pea leaf weevil in field crops is posted by the province of Alberta and in the PPMN monitoring protocol.

Also refer to the pea leaf weevil page within the “Field Crop and Forage Pests and their Natural Enemies in Western Canada: Identification and management field guide” – both English-enhanced or French-enhanced versions are available.  A review of this insect was published in 2011 in Prairie Soils and Crops by Carcamo and Vankosky.

Flea beetles

Flea Beetles (Chrysomelidae: Phyllotreta species) – Be on the lookout for flea beetle damage resulting from feeding on canola cotyledons but also on the stem.  Two species, Phyllotreta striolata and P. cruciferae, will feed on all cruciferous plants but they can cause economic levels of damage in canola during the seedling stages.

Remember, the Action Threshold for flea beetles on canola is 25% of cotyledon leaf area consumed.  Watch for shot-hole feeding in seedling canola but also watch the growing point and stems of seedlings which are particularly vulnerable to flea beetle feeding.

Estimating flea beetle feeding damage can be challenging.  Using a visual guide to estimate damage can be helpful.  Canola Watch circulated this article but also use the two images (copied below for reference) produced by Dr. J. Soroka (AAFC-Saskatoon)  – take it scouting!

Figure 1. Canola cotyledons with various percentages of leaf area consume owing to 
flea beetle feeding damage (Photo: Soroka & Underwood, AAFC-Saskatoon).
Figure 2.  Percent leaf area consumed by flea beetles feeding on canola seedlings 
(Photo: Soroka & Underwood, AAFC-Saskatoon).

Refer to the flea beetle page from the “Field Crop and Forage Pests and their Natural Enemies in Western Canada: Identification and management field guide” as an English-enhanced or French-enhanced version.

Pea leaf weevil

Pea Leaf Weevil (Sitona lineatus– The PLW model was run for Red Deer AB (Fig. 1) and Saskatoon SK (Fig. 2). The output suggests that PLW are beginning to become active and will begin to fly on warmer days (Figs. 1 and 2). 

Figure 1.  Predicted overwintered PLW adults near Red Deer AB as of April 30, 2019. 
Figure 2.  Predicted overwintered PLW adults near Saskatoon SK as of April 30, 2019. 

Pea leaf weevils emerge in the spring primarily by flying (at temperatures above 17ºC) or they may walk short distances. Pea leaf weevil movement into peas and faba beans is achieved primarily through flight.  Adults are slender, greyish-brown measuring approximately 5 mm in length (Fig. 3, Left).  

The pea leaf weevil resembles the sweet clover weevil (Sitona cylindricollis) but the former is distinguished by three light-coloured stripes extending length-wise down thorax and sometimes the abdomen.  All species of Sitona, including the pea leaf weevil, have a short snout.  

Figure 3.  Comparison images and descriptions of four Sitona species adults including pea leaf weevil (Left).

Adults will feed upon the leaf margins and growing points of legume seedlings (alfalfa, clover, dry beans, faba beans, peas) and produce a characteristic, scalloped (notched) edge.  Females lay 1000 to 1500 eggs in the soil either near or on developing pea or faba bean plants from May to June.

Biological and monitoring information related to pea leaf weevil in field crops is posted by the province of Alberta and in the PPMN monitoring protocol.

Also refer to the pea leaf weevil page within the “Field Crop and Forage Pests and their Natural Enemies in Western Canada: Identification and management field guide” – both English-enhanced or French-enhanced versions are available.  A review of this insect was published in 2011 in Prairie Soils and Crops by Carcamo and Vankosky.

Scouting Charts – Canola and Flax

Field scouting is critical – it enables the identification of potential risks to crops. Accurate identification of insect pests PLUS the application of established monitoring methods will enable growers to make informed pest management decisions.

We offer TWO generalized insect pest scouting charts to aid in-field scouting on the Canadian prairies:

1. CANOLA INSECT SCOUTING CHART

2018_ScoutingChart_Canola

2. FLAX INSECT SCOUTING CHART

2018_ScoutingChart_Flax

These charts feature hyperlinks directing growers to downloadable PDF pages within the “Field crop and forage pests and their natural enemies in western Canada: Identification and management field guide“.

Whenever possible, monitor and compare pest densities to established economic or action thresholds to protect and preserve pollinators and beneficial arthropods. Economic thresholds, by definition, help growers avoid crop losses related to outbreaking insect pest species.

Good luck with your scouting!

Pea leaf weevil

Pea Leaf Weevil (Sitona lineatus– The PLW model was run for Lethbridge AB (Fig. 1) and Saskatoon SK (Fig. 2). Output suggests that PLW are beginning to become active. 

Figure 1. Predicted PLW phenology at  Lethbridge AB based on long term climate data.
Values are based on model simulations (April 1 – April 23, 2019).
Figure 2. Predicted PLW phenology at Saskatoon SK based on long term climate data.
Values are based on model simulations (April 1 – April 23, 2019).

Pea leaf weevils emerge in the spring primarily by flying (at temperatures above 17ºC) or they may walk short distances. Pea leaf weevil movement into peas and faba beans is achieved primarily through flight.  Adults are slender, greyish-brown measuring approximately 5 mm in length (Fig. 3, Left).  

The pea leaf weevil resembles the sweet clover weevil (Sitona cylindricollis) but the former is distinguished by three light-coloured stripes extending length-wise down thorax and sometimes the abdomen.  All species of Sitona, including the pea leaf weevil, have a short snout.  

Figure 3  Comparison images and descriptions of four Sitona species adults including pea leaf weevil (Left).

Adults will feed upon the leaf margins and growing points of legume seedlings (alfalfa, clover, dry beans, faba beans, peas) and produce a characteristic, scalloped (notched) edge.  Females lay 1000 to 1500 eggs in the soil either near or on developing pea or faba bean plants from May to June.

Reminder – The risk map for pea leaf weevils was released in March 2019.  The map is based on the number of feeding notches observed in peas (Fig. 4).  

Figure 4. Estimates of pea leaf weevil (S. lineatus) densities based on feeding notches observed in peas grown in Alberta and Saskatchewan in 2018.

Biological and monitoring information related to pea leaf weevil in field crops is posted by the province of Alberta and in the PPMN monitoring protocol.

Also refer to the pea leaf weevil page within the “Field Crop and Forage Pests and their Natural Enemies in Western Canada: Identification and management field guide” – both English-enhanced or French-enhanced versions are available.  A review of this insect was published in 2011 in Prairie Soils and Crops by Carcamo and Vankosky.

Pea leaf weevil

Pea Leaf Weevil (Sitona lineatus– Over the past ten days newly emerged adult pea leaf weevils are predicted to be emerging from pea crops (Fig. 1).  

Figure 1. Predicted pea leaf weevil phenology at Saskatoon (A) and Lethbridge (B). Values are based on model simulations for the current growing season (April 1 – July 30, 2018).

Pea leaf weevil larvae develop under the soil over a period of 30 to 60 days. They are “C” shaped with a dark brown head capsule. The rest of the body is a milky-white color (Fig. 2 A). Larvae develop through five instar stages. In the 5th instar, larvae range in length from 3.5 – 5.5 mm. First instar larvae bury into the soil after hatching, and search out root nodules on field pea and faba bean plants. Larvae enter and consume the microbial contents of the root nodules (Fig. 2 B). These root nodules are responsible for nitrogen-fixation, thus pea leaf weevil larval feeding can affect plant yield and the plant’s ability to input nitrogen into the soil. 

Figure 2.  Pea leaf weevil larva in soil (A) and field pea root nodules damaged by larval feeding (B).  Photos: L. Dosdall).

Biological and monitoring information related to pea leaf weevil in field crops is posted by the province of Alberta and in the PPMN monitoring protocol.

Also refer to the pea leaf weevil page within the “Field Crop and Forage Pests and their Natural Enemies in Western Canada: Identification and management field guide” – both English-enhanced or French-enhanced versions are available.  A review of this insect was published in 2011 in Prairie Soils and Crops by Carcamo and Vankosky.

Pea leaf weevil

Pea Leaf Weevil (Sitona lineatus– As of June 24, 2018, the PLW model predicted that hatch is nearly complete and the population is primarily in the larval stage in the Saskatoon area (Fig. 1).  Development in 2018 is faster than long term average (Fig. 2).  

Figure 1.  Predicted pea leaf weevil phenology at Saskatoon SK.
Values are based on model simulations for April 1 – June 24, 2018.
Figure 2.  Predicted pea leaf weevil phenology at Saskatoon SK.
Values are based on model simulations for Long Term Climate Normals (LTCN).

Pea leaf weevil larvae develop under the soil over a period of 30 to 60 days. They are “C” shaped with a dark brown head capsule. The rest of the body is a milky-white color (Fig. 3 A). Larvae develop through five instar stages. In the 5th instar, larvae range in length from 3.5 – 5.5 mm. First instar larvae bury into the soil after hatching, and search out root nodules on field pea and faba bean plants. Larvae enter and consume the microbial contents of the root nodules (Fig. 3 B). These root nodules are responsible for nitrogen-fixation, thus pea leaf weevil larval feeding can affect plant yield and the plant’s ability to input nitrogen into the soil. 

Figure 3.  Pea leaf weevil larva in soil (A) and field pea root nodules damaged by larval feeding (B).  Photos: L. Dosdall).

Biological and monitoring information related to pea leaf weevil in field crops is posted by the province of Alberta and in the PPMN monitoring protocol.

Also refer to the pea leaf weevil page within the “Field Crop and Forage Pests and their Natural Enemies in Western Canada: Identification and management field guide” – both English-enhanced or French-enhanced versions are available.  A review of this insect was published in 2011 in Prairie Soils and Crops by Carcamo and Vankosky.

Pea leaf weevil

Pea Leaf Weevil (Sitona lineatus– The PLW model predicted that larvae should be appearing in fields near Saskatoon (Fig. 1). Development in 2018 is faster than that predicted using long term averages  (LTCN presented in Fig. 2).  

Figure 1.  Predicted pea leaf weevil phenology at Saskatoon SK.
Values are based on model simulations for April 1 – June 18, 2018.
Figure 2.  Predicted pea leaf weevil phenology at Saskatoon SK. 
Values are based on model simulations for April 1 – June 18, 2018. using Long Term Climate Normals.

Larvae develop under the soil over a period of 30 to 60 days. They are “C” shaped with a dark brown head capsule. The rest of the body is a milky-white color (Fig. 3 A). Larvae develop through five instar stages. In the 5th instar, larvae range in length from 3.5 – 5.5 mm. First instar larvae bury into the soil after hatching, and search out root nodules on field pea and faba bean plants. Larvae enter and consume the microbial contents of the root nodules (Fig. 3 B). These root nodules are responsible for nitrogen-fixation, thus pea leaf weevil larval feeding can affect plant yield and the plant’s ability to input nitrogen into the soil. 

Figure 3.  Pea leaf weevil larva in soil (A) and field pea root nodules damaged by larval feeding (B).  Photos: L. Dosdall).

Biological and monitoring information related to pea leaf weevil in field crops is posted by the province of Alberta and in the PPMN monitoring protocol.

Also refer to the pea leaf weevil page within the “Field Crop and Forage Pests and their Natural Enemies in Western Canada: Identification and management field guide” – both English-enhanced or French-enhanced versions are available.  A review of this insect was published in 2011 in Prairie Soils and Crops by Carcamo and Vankosky.

Pea leaf weevil

Pea Leaf Weevil (Sitona lineatus– The PLW model predicts that oviposition is nearly complete and PLW are primarily in the adult and egg stages (Fig. 1). Larvae should begin to appear later this week. 

Figure 1.  Predicted pea leaf weevil phenology at Red Deer AB.
Values are based on model simulations, for April 1-May 28, 2018 (projected to July 15, 2018).

Pea leaf weevils emerge in the spring primarily by flying (at temperatures above 17ºC) or they may walk short distances. Pea leaf weevil movement into peas and faba beans is achieved primarily through flight.  Adults are slender, greyish-brown measuring approximately 5 mm in length (view weevil adult photos here).

Adults feed upon the leaf margins and growing points of legume seedlings (alfalfa, clover, dry beans, faba beans, peas) and produce a characteristic, scalloped (notched) edge (Fig. 4).  Females lay 1000 to 1500 eggs in the soil either near or on developing pea or faba bean plants from May to June.

Figure 4.  Scalloped notching along leaf margins of pea plant (Photo: L. Dosdall).

Larvae develop under the soil over a period of 30 to 60 days. They are “C” shaped with a dark brown head capsule. The rest of the body is a milky-white color (Fig. 5 A). Larvae develop through five instar stages. In the 5th instar, larvae range in length from 3.5 – 5.5 mm. First instar larvae bury into the soil after hatching, and search out root nodules on field pea and faba bean plants. Larvae enter and consume the microbial contents of the root nodules (Fig. 5 B). These root nodules are responsible for nitrogen-fixation, thus pea leaf weevil larval feeding can affect plant yield and the plant’s ability to input nitrogen into the soil. 

Figure 5.  Pea leaf weevil larva in soil (A) and field pea root nodules damaged by larval feeding (B).  Photos: L. Dosdall).

Biological and monitoring information related to pea leaf weevil in field crops is posted by the province of Alberta and in the PPMN monitoring protocol.

Also refer to the pea leaf weevil page within the “Field Crop and Forage Pests and their Natural Enemies in Western Canada: Identification and management field guide” – both English-enhanced or French-enhanced versions are available.  A review of this insect was published in 2011 in Prairie Soils and Crops by Carcamo and Vankosky.

Pea leaf weevil

Pea Leaf Weevil (Sitona lineatus– The PLW model predicts that oviposition is occurring across southern and central regions of the prairies (example Red Deer (Fig. 9). 

Figure 1.  Predicted pea leaf weevil phenology at Red Deer AB. 
Values are based on model simulations, for April 1-May 28, 2018 (projected to July 15, 2018).

Pea leaf weevils emerge in the spring primarily by flying (at temperatures above 17ºC) or they may walk short distances. Pea leaf weevil movement into peas and faba beans is achieved primarily through flight.  Adults are slender, greyish-brown measuring approximately 5 mm in length (Fig. 2, Left).  

The pea leaf weevil resembles the sweet clover weevil (Sitona cylindricollis) but the former is distinguished by three light-coloured stripes extending length-wise down thorax and sometimes the abdomen.  All species of Sitona, including the pea leaf weevil, have a short snout.  

Figure 2.  Comparison images and descriptions of four Sitona species adults including pea leaf weevil (Left).

Adults will feed upon the leaf margins and growing points of legume seedlings (alfalfa, clover, dry beans, faba beans, peas) and produce a characteristic, scalloped (notched) edge.  Females lay 1000 to 1500 eggs in the soil either near or on developing pea or faba bean plants from May to June.

Reminder – The 2017 risk map for pea leaf weevils was released in March 2018.  The map is based on the number of feeding notches observed in peas (Fig. 3).  

Figure 3. Estimates of pea leaf weevil (S. lineatus) densities based on feeding notches observed in peas grown in Alberta and Saskatchewan in 2017.

Biological and monitoring information related to pea leaf weevil in field crops is posted by the province of Alberta and in the PPMN monitoring protocol.

Also refer to the pea leaf weevil page within the “Field Crop and Forage Pests and their Natural Enemies in Western Canada: Identification and management field guide” – both English-enhanced or French-enhanced versions are available.  A review of this insect was published in 2011 in Prairie Soils and Crops by Carcamo and Vankosky.

Flea beetles

Flea Beetles (Chrysomelidae: Phyllotreta species) – The Insect of the Week features flea beetles!


Be on the lookout for flea beetle damage resulting from feeding on canola cotyledons but also on the stem.  Two species, Phyllotreta striolata and P. cruciferae, will feed on all cruciferous plants but they can cause economic levels of damage in canola during the seedling stages.


Remember, the Action Threshold for flea beetles on canola is 25% of cotyledon leaf area consumed.  Watch for shot-hole feeding in seedling canola but also watch the growing point and stems of seedlings which are particularly vulnerable to flea beetle feeding.


Estimating flea beetle feeding damage can be challenging.  Using a visual guide to estimate damage can be helpful.  Canola Watch circulated this article but also use the two images (copied below for reference) produced by Dr. J. Soroka (AAFC-Saskatoon)  – take it scouting!

Figure 1. Canola cotyledons with various percentages of leaf area consume owing to 
flea beetle feeding damage (Photo: Soroka & Underwood, AAFC-Saskatoon).

Figure 2.  Percent leaf area consumed by flea beetles feeding on canola seedlings 
(Photo: Soroka & Underwood, AAFC-Saskatoon).


Refer to the flea beetle page from the “Field Crop and Forage Pests and their Natural Enemies in Western Canada: Identification and management field guide” as an English-enhanced or French-enhanced version.

Pea leaf weevil

Pea Leaf Weevil (Sitona lineatus– The PLW model predicts that oviposition is occurring across southern and central regions of the prairies (example Swift Current – Fig. 1). 

Figure 1.  Predicted pea leaf weevil phenology at Swift Current SK.
Values are based on model simulations (April 1-May 28, 2018 and projected to July 1, 2018).



Pea leaf weevils emerge in the spring primarily by flying (at temperatures above 17ºC) or they may walk short distances. Pea leaf weevil movement into peas and faba beans is achieved primarily through flight.  Adults are slender, greyish-brown measuring approximately 5 mm in length (Fig. 2, Left).  

The pea leaf weevil resembles the sweet clover weevil (Sitona cylindricollis) but the former is distinguished by three light-coloured stripes extending length-wise down thorax and sometimes the abdomen.  All species of Sitona, including the pea leaf weevil, have a short snout.  


Figure 2.  Comparison images and descriptions of four Sitona species adults including pea leaf weevil (Left).


Adults will feed upon the leaf margins and growing points of legume seedlings (alfalfa, clover, dry beans, faba beans, peas) and produce a characteristic, scalloped (notched) edge.  Females lay 1000 to 1500 eggs in the soil either near or on developing pea or faba bean plants from May to June.


Reminder – The 2017 risk map for pea leaf weevils was released in March 2018.  The map is based on the number of feeding notches observed in peas (Fig. 3).  

Figure 3. Estimates of pea leaf weevil (S. lineatus) densities based on feeding notches observed in
peas grown in Alberta and Saskatchewan in 2017.

Biological and monitoring information related to pea leaf weevil in field crops is posted by the province of Alberta and in the PPMN monitoring protocol.

Also refer to the pea leaf weevil page within the “Field Crop and Forage Pests and their Natural Enemies in Western Canada: Identification and management field guide” – both English-enhanced or French-enhanced versions are available.  A review of this insect was published in 2011 in Prairie Soils and Crops by Carcamo and Vankosky.

Flea beetles

Flea Beetles (Chrysomelidae: Phyllotreta species) – Be on the lookout for flea beetle damage resulting from feeding on canola cotyledons but also on the stem.  Two species, Phyllotreta striolata and P. cruciferae, will feed on all cruciferous plants but they can cause economic levels of damage in canola during the seedling stages.


Remember, the Action Threshold for flea beetles on canola is 25% of cotyledon leaf area consumed.  Watch for shot-hole feeding in seedling canola but also watch the growing point and stems of seedlings which are particularly vulnerable to flea beetle feeding.


Estimating flea beetle feeding damage can be challenging.  Using a visual guide to estimate damage can be helpful.  Canola Watch circulated this article but also use the two images (copied below for reference) produced by Dr. J. Soroka (AAFC-Saskatoon)  – take it scouting!

Figure 1. Canola cotyledons with various percentages of leaf area consume owing to 
flea beetle feeding damage (Photo: Soroka & Underwood, AAFC-Saskatoon).

Figure 2.  Percent leaf area consumed by flea beetles feeding on canola seedlings 
(Photo: Soroka & Underwood, AAFC-Saskatoon).


Refer to the flea beetle page from the “Field Crop and Forage Pests and their Natural Enemies in Western Canada: Identification and management field guide” as an English-enhanced or French-enhanced version.

Pea leaf weevil

Pea Leaf Weevil (Sitona lineatus– The PLW model predicts that adult weevils should be out and that oviposition may be occurring in fields with emerging peas.  An example of PLW predicted phenology for Swift Current SK is presented in Figure 1. 

Figure 1. Predicted PLW phenology at Swift Current, SK. Values are based on model simulations,
for April 1 – May 21, 2018 (projected to July 1, 2018).



Pea leaf weevils emerge in the spring primarily by flying (at temperatures above 17ºC) or they may walk short distances. Pea leaf weevil movement into peas and faba beans is achieved primarily through flight.  Adults are slender, greyish-brown measuring approximately 5 mm in length (Fig. 2, Left).  

The pea leaf weevil resembles the sweet clover weevil (Sitona cylindricollis) but the former is distinguished by three light-coloured stripes extending length-wise down thorax and sometimes the abdomen.  All species of Sitona, including the pea leaf weevil, have a short snout.  


Figure 2.  Comparison images and descriptions of four Sitona species adults including pea leaf weevil (Left).


Adults will feed upon the leaf margins and growing points of legume seedlings (alfalfa, clover, dry beans, faba beans, peas) and produce a characteristic, scalloped (notched) edge.  Females lay 1000 to 1500 eggs in the soil either near or on developing pea or faba bean plants from May to June.


Reminder – The 2017 risk map for pea leaf weevils was released in March 2018.  The map is based on the number of feeding notches observed in peas (Fig. 3).  

Figure 3. Estimates of pea leaf weevil (S. lineatus) densities based on feeding notches observed in
peas grown in Alberta and Saskatchewan in 2017.

Biological and monitoring information related to pea leaf weevil in field crops is posted by the province of Alberta and in the PPMN monitoring protocol.

Also refer to the pea leaf weevil page within the “Field Crop and Forage Pests and their Natural Enemies in Western Canada: Identification and management field guide” – both English-enhanced or French-enhanced versions are available.  A review of this insect was published in 2011 in Prairie Soils and Crops by Carcamo and Vankosky.

Scouting Charts – Canola and Flax

Field scouting is critical – it enables the identification of potential risks to crops. Accurate identification of insect pests PLUS the application of established monitoring methods will enable growers to make informed pest management decisions.

We offer TWO generalized insect pest scouting charts to aid in-field scouting on the Canadian prairies:

1. CANOLA INSECT SCOUTING CHART

    

2. A NEW FLAX INSECT SCOUTING CHART

    
These charts feature hyperlinks directing growers to downloadable PDF pages within the “Field crop and forage pests and their natural enemies in western Canada: Identification and management field guide“.

Whenever possible, monitor and compare pest densities to established economic or action thresholds to protect and preserve pollinators and beneficial arthropods. Economic thresholds, by definition, help growers avoid crop losses related to outbreaking insect pest species.

Good luck with your scouting!

Scouting Charts – Canola and Flax

Field scouting is critical – it enables the identification of potential risks to crops. Accurate identification of insect pests PLUS the application of established monitoring methods will enable growers to make informed pest management decisions.

We offer TWO generalized insect pest scouting charts to aid in-field scouting on the Canadian prairies:

1. CANOLA INSECT SCOUTING CHART

    

2. A NEW FLAX INSECT SCOUTING CHART

    
These charts feature hyperlinks directing growers to downloadable PDF pages within the “Field crop and forage pests and their natural enemies in western Canada: Identification and management field guide“.

Whenever possible, monitor and compare pest densities to established economic or action thresholds to protect and preserve pollinators and beneficial arthropods. Economic thresholds, by definition, help growers avoid crop losses related to outbreaking insect pest species.

Good luck with your scouting!

Flea beetles

Flea Beetles (Chrysomelidae: Phyllotreta species) – Be on the lookout for flea beetle damage resulting from feeding on canola cotyledons but also on the stem.  Two species, Phyllotreta striolata and P. cruciferae, will feed on all cruciferous plants but they can cause economic levels of damage in canola during the seedling stages.


Remember, the Action Threshold for flea beetles on canola is 25% of cotyledon leaf area consumed.  Watch for shot-hole feeding in seedling canola but also watch the growing point and stems of seedlings which are particularly vulnerable to flea beetle feeding.


Estimating flea beetle feeding damage can be challenging.  Using a visual guide to estimate damage can be helpful.  Canola Watch circulated this article but also use the two images (copied below for reference) produced by Dr. J. Soroka (AAFC-Saskatoon)  – take it scouting!

Figure 1. Canola cotyledons with various percentages of leaf area consume owing to 
flea beetle feeding damage (Photo: Soroka & Underwood, AAFC-Saskatoon).

Figure 2.  Percent leaf area consumed by flea beetles feeding on canola seedlings 
(Photo: Soroka & Underwood, AAFC-Saskatoon).


Refer to the flea beetle page from the “Field Crop and Forage Pests and their Natural Enemies in Western Canada: Identification and management field guide” as an English-enhanced or French-enhanced version.

Pea leaf weevil

Pea Leaf Weevil (Sitona lineatus– The PLW model predicts that adults are beginning to fly. This is similar to model output based on long term (climate) data.  Model output estimates that oviposition should begin in late May or early June (Fig. 1).

Figure 1. Predicted PLW phenology at Swift Current based on long term climate data.
Values are based on model simulations (April 1 – May 6).

Pea leaf weevils emerge in the spring primarily by flying (at temperatures above 17ºC) or they may walk short distances. Pea leaf weevil movement into peas and faba beans is achieved primarily through flight.  Adults are slender, greyish-brown measuring approximately 5 mm in length (Fig. 2, Left).  

The pea leaf weevil resembles the sweet clover weevil (Sitona cylindricollis) but the former is distinguished by three light-coloured stripes extending length-wise down thorax and sometimes the abdomen.  All species of Sitona, including the pea leaf weevil, have a short snout.  


Figure 2.  Comparison images and descriptions of four Sitona species adults including pea leaf weevil (Left).


Adults will feed upon the leaf margins and growing points of legume seedlings (alfalfa, clover, dry beans, faba beans, peas) and produce a characteristic, scalloped (notched) edge.  Females lay 1000 to 1500 eggs in the soil either near or on developing pea or faba bean plants from May to June.



Reminder – The 2017 risk map for pea leaf weevils was released in March 2018.  The map is based on the number of feeding notches observed in peas (Fig. 3).  

Figure 3. Estimates of pea leaf weevil (S. lineatus) densities based on feeding notches observed in
peas grown in Alberta and Saskatchewan in 2017.

Biological and monitoring information related to pea leaf weevil in field crops is posted by the province of Alberta and in the PPMN monitoring protocol.

Also refer to the pea leaf weevil page within the “Field Crop and Forage Pests and their Natural Enemies in Western Canada: Identification and management field guide” – both English-enhanced or French-enhanced versions are available.  A review of this insect was published in 2011 in Prairie Soils and Crops by Carcamo and Vankosky.

Flea beetles

Flea Beetles (Chrysomelidae: Phyllotreta species) – Be on the lookout for flea beetle damage resulting from feeding on canola cotyledons but also on the stem.  Two species, Phyllotreta striolata and P. cruciferae, will feed on all cruciferous plants but they can cause economic levels of damage in canola during the seedling stages.


Remember, the Action Threshold for flea beetles on canola is 25% of cotyledon leaf area consumed.  Watch for shot-hole feeding in seedling canola but also watch the growing point and stems of seedlings which are particularly vulnerable to flea beetle feeding.


Estimating flea beetle feeding damage can be challenging.  Using a visual guide to estimate damage can be helpful.  Canola Watch circulated this article but also use the two images (copied below for reference) produced by Dr. J. Soroka (AAFC-Saskatoon)  – take it scouting!

Figure 1. Canola cotyledons with various percentages of leaf area consume owing to 
flea beetle feeding damage (Photo: Soroka & Underwood, AAFC-Saskatoon).

Figure 2.  Percent leaf area consumed by flea beetles feeding on canola seedlings 
(Photo: Soroka & Underwood, AAFC-Saskatoon).


Refer to the flea beetle page from the “Field Crop and Forage Pests and their Natural Enemies in Western Canada: Identification and management field guide” as an English-enhanced or French-enhanced version.

Pea leaf weevil

Pea Leaf Weevil (Sitona lineatus– The PLW model predicts that adults are emerging from overwintering sites and beginning to fly. This is similar to model output based on long term (climate) data.  Looking forward, based on long term average climate data, oviposition should occur in late May or early June (Fig. 1).

Figure 1. Predicted PLW phenology at Swift Current based on long term climate data. Values are
based on model simulations (April 1 – May 6).

Pea leaf weevils emerge in the spring primarily by flying (at temperatures above 17ºC) or they may walk short distances. Pea leaf weevil movement into peas and faba beans is achieved primarily through flight.  Adults are slender, greyish-brown measuring approximately 5 mm in length (Fig. 1, Left).  

The pea leaf weevil resembles the sweet clover weevil (Sitona cylindricollis) but the former is distinguished by three light-coloured stripes extending length-wise down thorax and sometimes the abdomen.  All species of Sitona, including the pea leaf weevil, have a short snout.  


Figure 1.  Comparison images and descriptions of four Sitona species adults including pea leaf weevil (Left).


Adults will feed upon the leaf margins and growing points of legume seedlings (alfalfa, clover, dry beans, faba beans, peas) and produce a characteristic, scalloped (notched) edge.  Females lay 1000 to 1500 eggs in the soil either near or on developing pea or faba bean plants from May to June.


Biological and monitoring information related to pea leaf weevil in field crops is posted by the province of Alberta and in the PPMN monitoring protocol.


Also refer to the pea leaf weevil page within the “Field Crop and Forage Pests and their Natural Enemies in Western Canada: Identification and management field guide” – both English-enhanced or French-enhanced versions are available.  A review of this insect was published in 2011 in Prairie Soils and Crops by Carcamo and Vankosky.

Scouting Charts – Canola and Flax

Field scouting is critical – it enables the identification of potential risks to crops. Accurate identification of insect pests PLUS the application of established monitoring methods will enable growers to make informed pest management decisions.

We offer TWO generalized insect pest scouting charts to aid in-field scouting on the Canadian prairies:

1. CANOLA INSECT SCOUTING CHART

    

2. A NEW FLAX INSECT SCOUTING CHART

    
These charts feature hyperlinks directing growers to downloadable PDF pages within the “Field crop and forage pests and their natural enemies in western Canada: Identification and management field guide“.

Whenever possible, monitor and compare pest densities to established economic or action thresholds to protect and preserve pollinators and beneficial arthropods. Economic thresholds, by definition, help growers avoid crop losses related to outbreaking insect pest species.

Good luck with your scouting!

Weekly Update – Predicted Bertha Armyworm Development

Bertha armyworm (Lepidoptera: Mamestra configurata– Bertha armyworm should be in the adult stage across the prairies this week.  The map illustrates predicted appearance of adults (percent of the population) across the southern prairies.

For those monitoring BAW pheromone traps, compare trap “catches” to the following reference photo kindly shared by Saskatchewan Agriculture:



Biological and monitoring information related to bertha armyworm in field crops is posted by the provinces of ManitobaSaskatchewanAlberta and the Prairie Pest Monitoring Network.  Also refer to the bertha armyworm pages within the new “Field Crop and Forage Pests and their Natural Enemies in Western Canada: Identification and management field guide” – both English-enhanced or French-enhanced versions are available.

Weekly Update – Alfalfa weevil

Alfalfa Weevil (Hypera postica) – Across the prairies, the model indicates that 95% of the population should be in the pupal stage. This week adults should be appearing at most locations. Output indicates that adult emergence is well underway at many southern locations (Brooks, Estevan) , while adult emergence at many central locations (Saskatoon) has begun over the last five days.







In terms of degree-day heat units, the map below reflects the predicted development of alfalfa weevil across the Canadian prairies.


Alfalfa growers are encouraged to check the Alfalfa Weevil Fact Sheet prepared by Dr. Julie Soroka (AAFC-Saskatoon) and additional information can be accessed by reviewing the Alfalfa Weevil Page extracted from the “Field crop and forage pests and their natural enemies in western Canada – Identification and management field guide” (Philip et al. 2015).  That guide is available in both a free English-enhanced or French-enhanced version.

Weekly Update – Predicted Bertha Armyworm Development

Bertha armyworm (Lepidoptera: Mamestra configurata– Bertha armyworm should be in the adult stage across the prairies this week.  The map illustrates predicted appearance of adults (percent of the population) across the southern prairies.

For those monitoring BAW pheromone traps, compare trap “catches” to the following reference photo kindly shared by Saskatchewan Agriculture:



Biological and monitoring information related to bertha armyworm in field crops is posted by the provinces of ManitobaSaskatchewanAlberta and the Prairie Pest Monitoring Network.  Also refer to the bertha armyworm pages within the new “Field Crop and Forage Pests and their Natural Enemies in Western Canada: Identification and management field guide” – both English-enhanced or French-enhanced versions are available.

Weekly Update – Alfalfa weevil

Alfalfa Weevil (Hypera postica) – Across the prairies, the model indicates that 80% of the population should be in the pupal stage. Adults should be appearing near Saskatoon this week.





In terms of degree-day heat units, the map below reflects the predicted development of alfalfa weevil across the Canadian prairies.



Alfalfa growers are encouraged to check the Alfalfa Weevil Fact Sheet prepared by Dr. Julie Soroka (AAFC-Saskatoon) and additional information can be accessed by reviewing the Alfalfa Weevil Page extracted from the “Field crop and forage pests and their natural enemies in western Canada – Identification and management field guide” (Philip et al. 2015).  That guide is available in both a free English-enhanced or French-enhanced version.

Weekly Update – Predicted Bertha Armyworm Development

Bertha armyworm (Lepidoptera: Mamestra configurata– Bertha armyworm should be in the adult stage across the prairies this week.  The map illustrates predicted appearance of adults (percent of the population) across the southern prairies.

For those monitoring BAW pheromone traps, compare trap “catches” to the following reference photo kindly shared by Saskatchewan Agriculture:



Biological and monitoring information related to bertha armyworm in field crops is posted by the provinces of ManitobaSaskatchewanAlberta and the Prairie Pest Monitoring Network.  Also refer to the bertha armyworm pages within the new “Field Crop and Forage Pests and their Natural Enemies in Western Canada: Identification and management field guide” – both English-enhanced or French-enhanced versions are available.

Weekly Update – Alfalfa weevil

Alfalfa Weevil (Hypera postica) – The model output for alfalfa weevil is not signficantly different that that posted last week for June 22nd (Week 7).

Alfalfa growers are encouraged to check the Alfalfa Weevil Fact Sheet prepared by Dr. Julie Soroka (AAFC-Saskatoon) and additional information can be accessed by reviewing the Alfalfa Weevil Page extracted from the “Field crop and forage pests and their natural enemies in western Canada – Identification and management field guide” (Philip et al. 2015).  That guide is available in both a free English-enhanced or French-enhanced version.

Weekly Update – Predicted Bertha Armyworm Development

Bertha armyworm (Lepidoptera: Mamestra configurata– Bertha armyworm should be in the adult stage across the prairies this week.  The map illustrates predicted appearance of adults (percent of the population) across the southern prairies.

For those monitoring BAW pheromone traps, compare trap “catches” to the following reference photo kindly shared by Saskatchewan Agriculture:



Biological and monitoring information related to bertha armyworm in field crops is posted by the provinces of ManitobaSaskatchewanAlberta and the Prairie Pest Monitoring Network.  Also refer to the bertha armyworm pages within the new “Field Crop and Forage Pests and their Natural Enemies in Western Canada: Identification and management field guide” – both English-enhanced or French-enhanced versions are available.

Weekly Update – Predicted Grasshopper Development

Grasshopper Simulation Model Output – Simulation modelling is used to predict grasshopper development across the prairies. Weekly temperature data is incorporated into the model which calculates estimates of grasshopper development stages based on biological parameters for Melanoplus sanguinipes (Migratory grasshopper). Predicted hatch for June 11, 2017, was 52% (23% last week) with 32% of the population in the first instar, 15% second instar and 15% third instar. 

The greatest development was predicted to be across southern regions in all three provinces, particularly southeastern Alberta and a region extending south from Swift Current/Regina to the US border. 



Grasshopper populations near Saskatoon were predicted to be primarily in the second instar with appearance of some third and fourth instars. This week’s survey (southwest of Saskatoon) agreed with model predictions with first collections of a few fourth instars.  





Model output for Grande Prairie indicates that development continues to be approximately 10 days later than locations across the southern prairies.

Reminder:  Biological and monitoring information related to grasshoppers in field crops is posted by Manitoba Agriculture, Food and Rural DevelopmentSaskatchewan AgricultureAlberta Agriculture and Forestry, the BC Ministry of Agriculture and the Prairie Pest Monitoring Network.  Also refer to the grasshopper pages within the new “Field Crop and Forage Pests and their Natural Enemies in Western Canada: Identification and management field guide” as an English-enhanced or French-enhanced version.

Weekly Update – Predicted Bertha Armyworm Development

Bertha armyworm (Lepidoptera: Mamestra configurata– Emergence of adult moths is well underway. The map illustrates predicted appearance of adults (percent of the population) across the southern prairies; oviposition is predicted to begin this week with first hatch beginning later next week.

For those of you monitoring BAW pheromone traps, you may want to compare trap “catches” to the following reference photo kindly shared by Saskatchewan Agriculture:



Biological and monitoring information related to bertha armyworm in field crops is posted by the provinces of ManitobaSaskatchewanAlberta and the Prairie Pest Monitoring Network.  Also refer to the bertha armyworm pages within the new “Field Crop and Forage Pests and their Natural Enemies in Western Canada: Identification and management field guide” – both English-enhanced or French-enhanced versions are available.

Weekly Update – Pea leaf weevil

Pea Leaf Weevil (Sitona lineatus– Oviposition is predicted to have peaked across central and southern regions of Alberta and Saskatchewan.  Hatch should be underway in pea fields near Lethbridge while hatching is predicted to occur this week near Saskatoon. 

Biological and monitoring information related to pea leaf weevil in field crops is posted by the province of Alberta and a NEWLY UPDATED PPMN monitoring protocol is available!

Also refer to the pea leaf weevil page within the “Field Crop and Forage Pests and their Natural Enemies in Western Canada: Identification and management field guide” – both English-enhanced or French-enhanced versions are available.  A review of this insect was published in 2011 in Prairie Soils and Crops by Carcamo and Vankosky.

Weekly Update – Alfalfa weevil

Alfalfa Weevil (Hypera postica) – Recent warm weather has resulted in rapid alfalfa weevil development. Model output indicates that 98% of the hatch is complete (less than 80% last week). Larval populations should be predominantly in the second (35%) and third (46%) instars.

Alfalfa growers are encouraged to check the Alfalfa Weevil Fact Sheet prepared by Dr. Julie Soroka (AAFC-Saskatoon) and additional information can be accessed by reviewing the Alfalfa Weevil Page extracted from the “Field crop and forage pests and their natural enemies in western Canada – Identification and management field guide” (Philip et al. 2015).  That guide is available in both a free English-enhanced or French-enhanced version.

Weekly Update – Cereal leaf beetle

Cereal leaf beetle (Oulema melanopus) – As of June 5, 2017, model output indicates that oviposition should be nearly complete and larval populations should peak across the southern prairies

Lifecycle and Damage:
Adult: Adult cereal leaf beetles (CLB) have shiny bluish-black wing-covers (Fig. 2). The thorax and legs are light orange-brown. Females (4.9 to 5.5 mm) are slightly larger than the males (4.4 to 5 mm). Adult beetles overwinter in and along the margins of grain fields in protected places such as in straw stubble, under crop and leaf litter, and in the crevices of tree bark. They favour sites adjacent to shelter belts, deciduous and conifer forests. They emerge in the spring once temperature reaches 10-15 ºC and are active for about 6 weeks. They usually begin feeding on grasses, then move into winter cereals and later into spring cereals.  

Figure 2. Adult Oulema melanopus (~4.4-5.5 mm long).


Egg: Eggs are laid approximately 14 days following the emergence of the adults. Eggs are laid singly or in pairs along the mid vein on the upper side of the leaf and are cylindrical, measuring 0.9 mm by 0.4 mm, and yellowish in colour. Eggs darken to black just before hatching.  

Larva: The larvae hatch in about 5 days and feed for about 3 weeks, passing through 4 growth stages (instars). The head and legs are brownish-black; the body is yellowish. Larvae are usually covered with a secretion of mucus and fecal material, giving them a shiny black, wet appearance (Fig. 3).  When the larva completes its growth, it drops to the ground and pupates in the soil. 

Figure 3.  Larval stage of Oulema melanopus with characteristic feeding damage visible on leaf.


Pupa: Pupal colour varies from a bright yellow when it is first formed, to the colour of the adult just before emergence. The pupal stage lasts 2 – 3 weeks. Adult beetles emerge and feed for a couple of weeks before seeking overwintering sites. There is one generation per year.

Fact sheets for CLB are published by the province of Alberta and available from the Prairie Pest Monitoring Network. Also access the Oulema melanopus page from the new “Field crop and forage pests and their natural enemies in western Canada – Identification and management field guide”.

Weekly Update – Alfalfa weevil

Alfalfa Weevil (Hypera postica) – Reminder – Biological information and photos of all life stages of this insect can reviewed on the Week 4 post.  The larval stage of this weevil feeds on alfalfa leaves in a manner that characterizes the pest as a “skeletonizer”.  

Degree-day maps of base 9°C are now being produced by Soroka, Olfert, and Giffen (2016) using the Harcourt/North Dakota models.  Models predicting the development of Alfalfa weevil across the prairies are updated weekly to help growers time their in-field scouting for second-instar larvae.  Compare the following predicted development stages and degree-day values from Soroka (2015) to the map below.



As of June 4, 2017, the recent warm weather has resulted in rapid development, indicating that 80% of the hatch is probably complete (less than 20% last week). Larval populations should be predominantly in the first and second instars (less than 10% are predicted to be third instars). 


Figure 1.  Heat units accumulated necessary for the development of Alfalfa weevil 
(Hypera posticaacross the Canadian prairies (April 1-June 4, 2017).


Remember – Use the photo below as a visual reference to identify alfalfa weevil larvae.  Note the white dorsal line, the tapered shape of the abdomen and the dark head capsule.


Alfalfa growers are encouraged to check the Alfalfa Weevil Fact Sheet prepared by Dr. Julie Soroka (AAFC-Saskatoon) and additional information can be accessed by reviewing the Alfalfa Weevil Page extracted from the “Field crop and forage pests and their natural enemies in western Canada – Identification and management field guide” (Philip et al. 2015).  That guide is available in both a free English-enhanced or French-enhanced version.

Weekly Update – Pea leaf weevil

Pea Leaf Weevil (Sitona lineatus– This week, weevil oviposition is predicted to be occurring across central and southern regions of Alberta and Saskatchewan.   











The PLW Blitz continues this week and features:
– The Insect of the Week from June 1st, 
– A NEWLY UPDATED Monitoring Protocol (Vankosky et al. 2017), AND
– The current Insect of the Week features a group of beetles recognized as general predators but one species is an egg predator associated with Pea leaf weevil.



Remember – Pea leaf weevils emerge in the spring primarily by flying (at temperatures above 17ºC) or they may walk short distances. Pea leaf weevil movement into peas and faba beans is achieved primarily through flight.  Adults are slender, greyish-brown measuring approximately 5 mm in length (Fig. 3, Left).  


The pea leaf weevil resembles the sweet clover weevil (Sitona cylindricollis) but the former is distinguished by three light-coloured stripes extending length-wise down thorax and sometimes the abdomen.  All species of Sitona, including the pea leaf weevil, have a short snout.  



Figure 3.  Comparison images and descriptions of four Sitona species adults including pea leaf weevil (Left).


Adults feed upon the leaf margins and growing points of legume seedlings (alfalfa, clover, dry beans, faba beans, peas) and produce a characteristic, scalloped (notched) edge (Fig. 4).  Females lay 1000 to 1500 eggs in the soil either near or on developing pea or faba bean plants from May to June.


Figure 4.  Scalloped notching along leaf margins of pea plant (Photo: L. Dosdall).




Biological and monitoring information related to pea leaf weevil in field crops is posted by the province of Alberta and a NEWLY UPDATED PPMN monitoring protocol is available!

Also refer to the pea leaf weevil page within the “Field Crop and Forage Pests and their Natural Enemies in Western Canada: Identification and management field guide” – both English-enhanced or French-enhanced versions are available.  A review of this insect was published in 2011 in Prairie Soils and Crops by Carcamo and Vankosky.

Weekly Update – Predicted Grasshopper Development

Grasshopper Simulation Model Output – The grasshopper simulation model will be used to monitor grasshopper development across the prairies. Weekly temperature data collected across the prairies is incorporated into the simulation model which calculates estimates of grasshopper development stages based on biological parameters for Melanoplus sanguinipes (Migratory grasshopper).  



As of June 5, 2017, model output suggests that most of the population is still at the egg stage. However, recent warm conditions have advanced grasshopper development. Predicted hatch was 23% (17% first instar and 6% second instar) across the prairies (up from 7% last week). Development was predicted to be most advanced across southern regions in all three provinces, particularly southeastern Alberta and a region extending south from Regina to the USA border. 



Though it is still early in the growing season, grasshopper hatch can vary across the prairies. Model output indicates that development near Vauxhall is one week ahead of Saskatoon and three weeks faster than Grande Prairie. This suggests that peak hatch at Grande Prairie may not occur until late June.






The following image showing various stages of the clearwinged grasshopper is provided below – note that adults have wings extending the length of the abdomen whereas nymphs lack wings but develop wing buds that will eventually mature to wings.  


Reminder:
– The Prairie Pest Monitoring Network’s 2017 Grasshopper Forecast Map can be viewed here.  

Biological and monitoring information related to grasshoppers in field crops is posted by Manitoba Agriculture, Food and Rural DevelopmentSaskatchewan AgricultureAlberta Agriculture and Forestry, the BC Ministry of Agriculture and the Prairie Pest Monitoring Network.  Also refer to the grasshopper pages within the new “Field Crop and Forage Pests and their Natural Enemies in Western Canada: Identification and management field guide” as an English-enhanced or French-enhanced version.

Weekly Update – Predicted Bertha Armyworm Development

Bertha armyworm (Lepidoptera: Mamestra configurata– Warm conditions over the past week has advanced pupal development across the southern prairies. Compared to last week, adult emergence is predicted to be 1-7 days earlier. The first map shows that pupal development is well underway across southern and central regions. Average development was 70% (50% last week). Pupal development at a number of locations was 75%. 

The second map indicates that development, compared to long-term-average, is slightly greater than average development. Model output indicted that first adult emergence may occur this week in the Vauxhall, Brooks and Regina areas. 

IMPORTANT – The table indicates predicted dates of first appearance of adults for specific locations across the prairies. Adult emergence generally occurs within 5-7 days after 80% development. 



Reminder – The video below posted by Alberta Agriculture and Forestry’s Scott Meers describes how pheromone traps are used to monitor this important pest of canola.





Those monitoring BAW pheromone traps may want to compare trap “catches” to the following reference photo kindly shared by Saskatchewan Agriculture below:





Biological and monitoring information related to bertha armyworm in field crops is posted by the provinces of ManitobaSaskatchewanAlberta and the Prairie Pest Monitoring Network.  Also refer to the bertha armyworm pages within the new “Field Crop and Forage Pests and their Natural Enemies in Western Canada: Identification and management field guide” – both English-enhanced or French-enhanced versions are available.

Weekly Update – Cutworms

Cutworms (Noctuidae) – NEW – Just in time for spring scouting!  A new field guide is now available to help growers scout and manage Cutworms!  Cutworm Pest of Crops is now available for free in either English or French and is featured at our new Cutworm Field Guide!  

Keep an eye on fields that are “slow” to emerge, are missing rows, include wilting or yellowing plants, have bare patches, or appear highly attractive to birds – these are areas warranting a closer look.  Plan to follow-up by walking these areas later in the day when some cutworm species move above-ground to feed.  Start to dig below the soil surface (1-5 cm deep) near the base of a symptomatic plant or the adjacent healthy plant.  If the plant is well-established, check within the crown in addition to the adjacent soil.  The culprits could be wireworms or cutworms.  


Several species of cutworms can be present in fields.  They range in colour from shiny opaque, to tan, to brownish-red with chevron patterning.  Cutworm biology, species information, plus monitoring recommendations are available in the Prairie Pest Monitoring Network’s Cutworm Monitoring Protocol.  Also refer to the Manitoba Agriculture cutworm fact sheet which includes action and economic thresholds for cutworms in several crops. 


For Albertans….. If you find cutworms, please consider using the Alberta Pest Surveillance Network’s “2017 Cutworm Reporting Tool”.  The map now has reports of pale western and redbacked cutworms in central and southern Alberta so view the live 2017 cutworm map.


Check the Insect of the Week – the month of May highlighted cutworms!  Be sure to read more about Pale western cutworms, Redbacked cutworms, Army cutwormsDingy cutworms.

Remember the NEW Cutworm Field Guide is free and downloadable in 2017!

Weekly Update – Cereal leaf beetle

Cereal leaf beetle (Oulema melanopus) – As of May 29, 2017, the CLB model indicates that larvae should be present across the southern prairies (Fig. 1). Compared to Lethbridge AB, populations near Brandon MB are predicted to be delayed by approximately five days. At Lethbridge, the hatch should be almost complete, while hatch should be approximately 50% complete near Brandon.

Figure 1. Predicted percent of Cereal leaf beetle (Oulema melanopus) in larval stage
across the Canadian prairies as of May 29, 2017.

Lifecycle and Damage:
Adult: Adult cereal leaf beetles (CLB) have shiny bluish-black wing-covers (Fig. 2). The thorax and legs are light orange-brown. Females (4.9 to 5.5 mm) are slightly larger than the males (4.4 to 5 mm). Adult beetles overwinter in and along the margins of grain fields in protected places such as in straw stubble, under crop and leaf litter, and in the crevices of tree bark. They favour sites adjacent to shelter belts, deciduous and conifer forests. They emerge in the spring once temperature reaches 10-15 ºC and are active for about 6 weeks. They usually begin feeding on grasses, then move into winter cereals and later into spring cereals.  

Figure 2. Adult Oulema melanopus (~4.4-5.5 mm long).


Egg: Eggs are laid approximately 14 days following the emergence of the adults. Eggs are laid singly or in pairs along the mid vein on the upper side of the leaf and are cylindrical, measuring 0.9 mm by 0.4 mm, and yellowish in colour. Eggs darken to black just before hatching.  

Larva: The larvae hatch in about 5 days and feed for about 3 weeks, passing through 4 growth stages (instars). The head and legs are brownish-black; the body is yellowish. Larvae are usually covered with a secretion of mucus and fecal material, giving them a shiny black, wet appearance (Fig. 3).  When the larva completes its growth, it drops to the ground and pupates in the soil. 

Figure 3.  Larval stage of Oulema melanopus with characteristic feeding damage visible on leaf.


Pupa: Pupal colour varies from a bright yellow when it is first formed, to the colour of the adult just before emergence. The pupal stage lasts 2 – 3 weeks. Adult beetles emerge and feed for a couple of weeks before seeking overwintering sites. There is one generation per year.

Fact sheets for CLB are published by the province of Alberta and available from the Prairie Pest Monitoring Network. Also access the Oulema melanopus page from the new “Field crop and forage pests and their natural enemies in western Canada – Identification and management field guide”.

Weekly Update – Flea beetles

Flea Beetles (Chrysomelidae: Phyllotreta species) – Be on the lookout for flea beetle damage resulting from feeding on canola cotyledons but also on the stem.  Two species, Phyllotreta striolata and P. cruciferae, will feed on all cruciferous plants but they can cause economic levels of damage in canola during the seedling stages.



Remember, the Action Threshold for flea beetles on canola is 25% of cotyledon leaf area consumed.  Watch for shot-hole feeding in seedling canola but also watch the growing point and stems of seedlings which are particularly vulnerable to flea beetle feeding.


Estimating flea beetle feeding damage can be challenging.  Using a visual guide to estimate damage can be helpful.  Canola Watch circulated this article but also use the two images (copied below for reference) produced by Dr. J. Soroka (AAFC-Saskatoon)  – take it scouting!

Figure 1. Canola cotyledons with various percentages of leaf area consume owing to 
flea beetle feeding damage (Photo: Soroka & Underwood, AAFC-Saskatoon).

Figure 2.  Percent leaf area consumed by flea beetles feeding on canola seedlings
 (Photo: Soroka & Underwood, AAFC-Saskatoon).


Refer to the flea beetle page from the new “Field Crop and Forage Pests and their Natural Enemies in Western Canada: Identification and management field guide” as an English-enhanced or French-enhanced version.

Weekly Update – Alfalfa weevil

Alfalfa Weevil (Hypera postica) – Reminder – Biological information and photos of all life stages of this insect can reviewed on the Week 4 post.  The larval stage of this weevil feeds on alfalfa leaves in a manner that characterizes the pest as a “skeletonizer”.  


Degree-day maps of base 9°C are now being produced by Soroka, Olfert, and Giffen (2016) using the Harcourt/North Dakota models.  Models predicting the development of Alfalfa weevil across the prairies are updated weekly to help growers time their in-field scouting for second-instar larvae.  Compare the following predicted development stages and degree-day values from Soroka (2015) to the map below.




As of May 29, 2017, embryological development (hatch) is predicted to be greatest across south and central regions of the prairies (Fig. 2). 

Figure 1.  Heat units accumulated necessary for the development of Alfalfa weevil (Hypera postica)
across the Canadian prairies (April 1-May 29, 2017).

The map below reflects the predicted stage of development of alfalfa weevil (as of May 29th) and suggests the percent of the population at first instar stage across the Canadian prairies (as of May 29th).

Figure 2.  Predicted percent of H. postica population at first instar stage
across the Canadian prairies (as of May 29, 2017).
Use the photo below as a visual reference to identify alfalfa weevil larvae.  Note the white dorsal line, the tapered shape of the abdomen and the dark head capsule.

Alfalfa growers are encouraged to check the Alfalfa Weevil Fact Sheet prepared by Dr. Julie Soroka (AAFC-Saskatoon) and additional information can be accessed by reviewing the Alfalfa Weevil Page extracted from the “Field crop and forage pests and their natural enemies in western Canada – Identification and management field guide” (Philip et al. 2015).  That guide is available in both a free English-enhanced or French-enhanced version.

Weekly Update – Pea leaf weevil

Pea Leaf Weevil (Sitona lineatus– This week is our PLW Blitz featuring this pest with:
  -The Insect of the Week
  -Updated model outputs and phenological predictions for 2017 (as of May 29, 2017), and 
  – A NEWLY UPDATED Monitoring Protocol (Vankosky et al. 2017)!


The PLW model was run for Lethbridge AB and Saskatoon SK. Current weather data was used then extended by Long Term Normal climate data (May 30-Jun 30) in order to predict pea leaf weevil phenology.  Compared to last week, model output indicated that oviposition has been delayed by ~5-7 days.  As of May 29th, phenologies for eggs and larvae were predicted to be similar for both locations (Fig. 1-2)

Figure 1. Pea leaf weevil model predicting phenology for 2017 near Saskatoon SK.


Figure 2. Pea leaf weevil model predicting phenology for 2017 near Lethbridge AB.





Pea leaf weevils emerge in the spring primarily by flying (at temperatures above 17ºC) or they may walk short distances. Pea leaf weevil movement into peas and faba beans is achieved primarily through flight.  Adults are slender, greyish-brown measuring approximately 5 mm in length (Fig. 3, Left).  

The pea leaf weevil resembles the sweet clover weevil (Sitona cylindricollis) but the former is distinguished by three light-coloured stripes extending length-wise down thorax and sometimes the abdomen.  All species of Sitona, including the pea leaf weevil, have a short snout.  


Figure 3.  Comparison images and descriptions of four Sitona species adults including pea leaf weevil (Left).


Adults will feed upon the leaf margins and growing points of legume seedlings (alfalfa, clover, dry beans, faba beans, peas) and produce a characteristic, scalloped (notched) edge.  Females lay 1000 to 1500 eggs in the soil either near or on developing pea or faba bean plants from May to June.


Biological and monitoring information related to pea leaf weevil in field crops is posted by the province of Alberta and a NEWLY UPDATED PPMN monitoring protocol is available!


Also refer to the pea leaf weevil page within the “Field Crop and Forage Pests and their Natural Enemies in Western Canada: Identification and management field guide” – both English-enhanced or French-enhanced versions are available.  A review of this insect was published in 2011 in Prairie Soils and Crops by Carcamo and Vankosky.


Weekly Update – Predicted Grasshopper Development

Grasshopper Simulation Model Output – The grasshopper simulation model will be used to monitor grasshopper development across the prairies. Weekly temperature data collected across the prairies is incorporated into the simulation model which calculates estimates of grasshopper development stages based on biological parameters for Melanoplus sanguinipes (Migratory grasshopper).  



As of May 29, 2017, predicted mean embryological development was 77% (70% last week); the greatest development was predicted to be across southern regions in all three provinces, particularly southern Alberta (Fig. 1). Hatch was predicted for a few, isolated locations with approximately 7% hatch (Fig. 1).

Figure 1. Predicted embryological development of Migratory grasshopper  (Melanoplus
sanguinipes
) eggs across the Canadian prairies as of May 29, 2017.



For comparison, the map below (Fig. 2) indicates that the predicted M. sanguinipes hatch is actually slower than normal. This week, 93% of the population should be in the egg stage and 6.5% in the first instar. Predicted warm conditions for May 31 and June 1 should result in completion of the egg stage.  Though it is still early in the growing season, grasshopper hatch can vary across the prairies. 

Figure 2.   Predicted embryological development of Migratory grasshopper  (Melanoplus sanguinipes) eggs
across the Canadian prairies as of May 29, 2017, using Long Term Normal data
.





Reminders:
– Review the predicted M. sanguinipes phenologies generated for Week 4 for Regina SK, Lethbridge AB and Grande Prairie AB.
– The Prairie Pest Monitoring Network’s 2017 Grasshopper Forecast Map can be viewed here.  

Biological and monitoring information related to grasshoppers in field crops is posted by Manitoba Agriculture, Food and Rural DevelopmentSaskatchewan AgricultureAlberta Agriculture and Forestry, the BC Ministry of Agriculture and the Prairie Pest Monitoring Network.  Also refer to the grasshopper pages within the new “Field Crop and Forage Pests and their Natural Enemies in Western Canada: Identification and management field guide” as an English-enhanced or French-enhanced version.

Weekly Update – Predicted Bertha Armyworm Development

Bertha armyworm (Lepidoptera: Mamestra configurata– As of May 28th, predicted pupal development is well underway. We are fortunate to have two methods projecting pupal development:
–> Figure 1 reflects pupal development BASED ON DEGREE DAYS ONLY.
–> Figure 2 reflects pupal development BASED ON CLIMEX MODELLING (i.e., incorporates environmental data + biological data for organisms) AND legend is designed to estimate WHEN PHEROMONE TRAPS SHOULD BE DEPLOYED (i.e., pheromone traps are best deployed at ~80% pupal development). 

Figure 1. Predicted stage of pupal development of overwintered Bertha armyworm (based on Degree-Day heat units) set to emerge in 2017.


FIGURE 2. Predicted pupal development of Bertha armyworm (based on Climex model and legend designed to reflect that pheromone traps are best deployed at ~80% pupal development).



More specifically, Figure 2 shows the average pupal development is 50% (36% last week), and as high as 75% at a number of locations. The three graphs below show that adult emergence is predicted to be six days sooner in the Winnipeg region than in fields near Vegreville and ten days sooner than the Yorkton area.  





IMPORTANTThe table indicates predicted dates of first appearance of adults for specific locations across the prairies. We generally suggest that traps go out when pupal development is at 80%. Adult emergence generally occurs within 5-7 days after 80% development. As of May 29, 2017, there is a large area in southern Alberta that is greater than 70%. 






Reminder – These maps will be updated weekly to aid those who deploy and monitor this moth using pheromone traps.  The video below posted by Alberta Agriculture and Forestry’s Scott Meers describes how pheromone traps are used to monitor this important pest of canola.


Biological and monitoring information related to bertha armyworm in field crops is posted by the provinces of ManitobaSaskatchewanAlberta and the Prairie Pest Monitoring Network.  Also refer to the bertha armyworm pages within the new “Field Crop and Forage Pests and their Natural Enemies in Western Canada: Identification and management field guide” – both English-enhanced or French-enhanced versions are available.

Weekly Update – Flea beetles

Flea Beetles (Chrysomelidae: Phyllotreta species) – Be on the lookout for flea beetle damage resulting from feeding on canola cotyledons but also on the stem.  Two species, Phyllotreta striolata and P. cruciferae, will feed on all cruciferous plants but they can cause economic levels of damage in canola during the seedling stages.



Remember, the Action Threshold for flea beetles on canola is 25% of cotyledon leaf area consumed.  Watch for shot-hole feeding in seedling canola but also watch the growing point and stems of seedlings which are particularly vulnerable to flea beetle feeding.


Estimating flea beetle feeding damage can be challenging.  Using a visual guide to estimate damage can be helpful.  Canola Watch circulated this article but also use the two images (copied below for reference) produced by Dr. J. Soroka (AAFC-Saskatoon)  – take it scouting!

Figure 1. Canola cotyledons with various percentages of leaf area consume owing to flea beetle feeding damage (Photo: Soroka & Underwood, AAFC-Saskatoon).

Figure 2.  Percent leaf area consumed by flea beetles feeding on canola seedlings (Photo: Soroka & Underwood, AAFC-Saskatoon).



Refer to the flea beetle page from the new “Field Crop and Forage Pests and their Natural Enemies in Western Canada: Identification and management field guide” as an English-enhanced or French-enhanced version.

Weekly Update – Cutworms

Cutworms (Noctuidae) – NEW – Just in time for spring scouting!  A new field guide is now available to help growers scout and manage Cutworms!  Cutworm Pest of Crops is now available for free in either English or French and is featured at our new Cutworm Field Guide!  Also be sure to check the Insect of the Week throughout May – it highlights cutworms!  Be sure to read more about Dingy cutworms.


Dingy cutworm larva (cc John Gavloski, Manitoba Agriculture)

Several species of cutworms can be present in fields.  They range in colour from shiny opaque, to tan, to brownish-red with chevron patterning.  Cutworm biology, species information, plus monitoring recommendations are available in the Prairie Pest Monitoring Network’s Cutworm Monitoring Protocol.  Also refer to the Manitoba Agriculture cutworm fact sheet which includes action and economic thresholds for cutworms in several crops. 

Keep an eye on fields that are “slow” to emerge, are missing rows, include wilting or yellowing plants, have bare patches, or appear highly attractive to birds – these are areas warranting a closer look.  Plan to follow-up by walking these areas later in the day when some cutworm species move above-ground to feed.  Start to dig below the soil surface (1-5 cm deep) near the base of a symptomatic plant or the adjacent healthy plant.  If the plant is well-established, check within the crown in addition to the adjacent soil.  The culprits could be wireworms or cutworms.  


For Albertans….. If you find cutworms, please consider using the Alberta Pest Surveillance Network’s “2017 Cutworm Reporting Tool”.  The map now has reports of pale western and redbacked cutworms in central and southern Alberta so view the live 2017 cutworm map.


Remember the NEW Cutworm Field Guide is free and downloadable in 2017!

Weekly Update – Cereal leaf beetle

Cereal leaf beetle (Oulema melanopus) – As of May 22, 2017, the CLB model indicates that oviposition is well underway across the southern prairies. Compared to southern Alberta and Saskatchewan, populations in southern Manitoba are predicted to be delayed by approximately five days (Fig. 1). Compared to 2016, development in 2017 is approximately 1 week later. Hatch is predicted to occur in isolated areas. 

Lifecycle and Damage:
Adult: Adult cereal leaf beetles (CLB) have shiny bluish-black wing-covers (Fig. 2). The thorax and legs are light orange-brown. Females (4.9 to 5.5 mm) are slightly larger than the males (4.4 to 5 mm). Adult beetles overwinter in and along the margins of grain fields in protected places such as in straw stubble, under crop and leaf litter, and in the crevices of tree bark. They favour sites adjacent to shelter belts, deciduous and conifer forests. They emerge in the spring once temperature reaches 10-15 ºC and are active for about 6 weeks. They usually begin feeding on grasses, then move into winter cereals and later into spring cereals.  

Figure 2. Adult Oulema melanopus (~4.4-5.5 mm long).


Egg: Eggs are laid approximately 14 days following the emergence of the adults. Eggs are laid singly or in pairs along the mid vein on the upper side of the leaf and are cylindrical, measuring 0.9 mm by 0.4 mm, and yellowish in colour. Eggs darken to black just before hatching.  

Larva: The larvae hatch in about 5 days and feed for about 3 weeks, passing through 4 growth stages (instars). The head and legs are brownish-black; the body is yellowish. Larvae are usually covered with a secretion of mucus and fecal material, giving them a shiny black, wet appearance (Fig. 3).  When the larva completes its growth, it drops to the ground and pupates in the soil. 

Figure 3.  Larval stage of Oulema melanopus with characteristic feeding damage visible on leaf.


Pupa: Pupal colour varies from a bright yellow when it is first formed, to the colour of the adult just before emergence. The pupal stage lasts 2 – 3 weeks. Adult beetles emerge and feed for a couple of weeks before seeking overwintering sites. There is one generation per year.

Fact sheets for CLB are published by the province of Alberta and available from the Prairie Pest Monitoring Network. Also access the Oulema melanopus page from the new “Field crop and forage pests and their natural enemies in western Canada – Identification and management field guide”.

Weekly Update – Pea leaf weevil

Pea Leaf Weevil (Sitona lineatus– The pea leaf weevil simulation model will be used to monitor weevil development across the prairies. Weekly temperature data collected across the prairies is incorporated into the simulation model which calculates estimates of weevil development stages based on biological parameters for Sitona lineatus.


The PLW model was run for Lethbridge AB and Saskatoon SK. Meteorological data (April 1 – May 15, 2017) and climate data (May 16- June 30) were used to predict PLW phenology.  Output indicates that PLW oviposition in Lethbridge is approximately one week earlier than Saskatoon.  Reminder – Access last week’s PLW model output predictions here.

Pea leaf weevils emerge in the spring primarily by flying (at temperatures above 17ºC) or they may walk short distances. Pea leaf weevil movement into peas and faba beans is achieved primarily through flight.  Adults are slender, greyish-brown measuring approximately 5 mm in length (Fig. 1, Left).  

The pea leaf weevil resembles the sweet clover weevil (Sitona cylindricollis) but the former is distinguished by three light-coloured stripes extending length-wise down thorax and sometimes the abdomen.  All species of Sitona, including the pea leaf weevil, have a short snout.  


Figure 3.  Comparison images and descriptions of four Sitona species adults including pea leaf weevil (Left).


Adults will feed upon the leaf margins and growing points of legume seedlings (alfalfa, clover, dry beans, faba beans, peas) and produce a characteristic, scalloped (notched) edge.  Females lay 1000 to 1500 eggs in the soil either near or on developing pea or faba bean plants from May to June.


Biological and monitoring information related to pea leaf weevil in field crops is posted by the province of Alberta.  Also refer to the pea leaf weevil page within the “Field Crop and Forage Pests and their Natural Enemies in Western Canada: Identification and management field guide” – both English-enhanced or French-enhanced versions are available.  A review of this insect was published in 2011 in Prairie Soils and Crops by Carcamo and Vankosky.

Weekly Update – Alfalfa weevil

Alfalfa Weevil (Hypera postica) – The larval stage of this weevil feeds on alfalfa leaves in a manner that characterizes the pest as a “skeletonizer”.  The green larva featuring a dorsal, white line down the length of its body has a dark brown head capsule and will grow to 9mm long.  Alfalfa growers are encouraged to check the Alfalfa Weevil Fact Sheet prepared by Dr. Julie Soroka (AAFC-Saskatoon).



Degree-day maps of base 9°C are now being produced by Soroka, Olfert, and Giffen (2016) using the Harcourt/North Dakota models.  Models predicting the development of Alfalfa weevil (Hypera postica) across the prairies are updated weekly to help growers time their in-field scouting for second-instar larvae.  Compare the following predicted development stages and degree-day values from Soroka (2015) to the map below.



This week, embryological development is greatest across south and central regions of Alberta and Saskatchewan and across southern Manitoba. Early hatch is predicted to occur in a region near Brooks AB and Regina SK and south to the USA border.



Use the figure below as a visual reference to identify alfalfa weevil larvae.  Note the white dorsal line, the tapered shape of the abdomen and the dark head capsule.

Additional information can be accessed by reviewing the Alfalfa Weevil Page extracted from the “Field crop and forage pests and their natural enemies in western Canada – Identification and management field guide” (Philip et al. 2015).  The guide is available in both a free English-enhanced or French-enhanced version.

Weekly Update – Predicted Grasshopper Development

Grasshopper Simulation Model Output – The grasshopper simulation model will be used to monitor grasshopper development across the prairies. Weekly temperature data collected across the prairies is incorporated into the simulation model which calculates estimates of grasshopper development stages based on biological parameters for Melanoplus sanguinipes (Migratory grasshopper).  


As of May 22, 2017, predicted mean embryological development was 70% (66% last week); the greatest development was predicted to be across southern regions in all three provinces (similar to long term averages; Fig. 1).  


Figure 1.  Simulation model outputs mapped to predict the embryological development of Migratory grasshopper  (Melanoplus sanguinipes) eggs across the Canadian prairies as of May 15, 2017).
 
Model output indicates that development near Regina SK (Fig 2, Top) is slightly greater than Lethbridge AB (Fig. 2, Middle). Hatch in Lethbridge is predicted to be two weeks ahead of model predictions for Grande Prairie AB (Fig 2, Bottom). 
 



Figure 2. Predicted development of Migratory grasshoppers near Regina SK (Top), Lethbridge AB (Middle), and Grande Prairie AB (Bottom). 
 

 

Reminder – The Prairie Pest Monitoring Network’s 2017 Grasshopper Forecast Map can be viewed here.  


Biological and monitoring information related to grasshoppers in field crops is posted by Manitoba Agriculture, Food and Rural DevelopmentSaskatchewan AgricultureAlberta Agriculture and Forestry, the BC Ministry of Agriculture and the Prairie Pest Monitoring Network.  Also refer to the grasshopper pages within the new “Field Crop and Forage Pests and their Natural Enemies in Western Canada: Identification and management field guide” as an English-enhanced or French-enhanced version.

Weekly Update – Predicted Bertha Armyworm Development

Bertha armyworm (Lepidoptera: Mamestra configurata– This week, predicted pupal development is well underway. Average development is 36% (27% last week); average development is 37% (Fig. 1). 

Figure 1. Predicted stage of pupal development of overwintered Bertha armyworm set to emerge in 2017.


Reminder – These maps will be updated weekly to aid those who deploy and monitor this moth using pheromone traps.  The video below posted by Alberta Agriculture and Forestry’s Scott Meers describes how pheromone traps are used to monitor this important pest of canola.



Biological and monitoring information related to bertha armyworm in field crops is posted by the provinces of ManitobaSaskatchewanAlberta and the Prairie Pest Monitoring Network.  Also refer to the bertha armyworm pages within the new “Field Crop and Forage Pests and their Natural Enemies in Western Canada: Identification and management field guide” – both English-enhanced or French-enhanced versions are available.

Weekly Update – Flea beetles

Flea Beetles (Chrysomelidae: Phyllotreta species) – Be on the lookout for flea beetle damage resulting from feeding on canola cotyledons but also on the stem.  Two species, Phyllotreta striolata and P. cruciferae, will feed on all cruciferous plants but they can cause economic levels of damage in canola during the seedling stages.




Remember, the Action Threshold for flea beetles on canola is 25% of cotyledon leaf area consumed.  Watch for shot-hole feeding in seedling canola but also watch the growing point and stems of seedlings which are particularly vulnerable to flea beetle feeding.



Estimating flea beetle feeding damage can be challenging.  Using a visual guide to estimate damage can be helpful.  Canola Watch circulated this article but also use the two images (copied below for reference) produced by Dr. J. Soroka (AAFC-Saskatoon)  – take it scouting!

Figure 1. Canola
cotyledons with various percentages of leaf area consume owing to flea beetle
feeding damage (Photo: Soroka & Underwood, AAFC-Saskatoon).

Figure 2.
 Percent leaf area consumed by flea beetles feeding on canola seedlings
(Photo: Soroka & Underwood, AAFC-Saskatoon).





Refer to the flea beetle page from the new “Field Crop and Forage Pests and their Natural Enemies in Western Canada: Identification and management field guide” as an English-enhanced or French-enhanced version.

Weekly Update – Cutworms

Cutworms (Noctuidae) – NEW – Just in time for spring scouting!  A new field guide is now available to help growers scout and manage Cutworms!  Cutworm Pest of Crops is now available for free in either English or French and is featured at our new Cutworm Field Guide!  Also be sure to check the Insect of the Week throughout May – it highlights cutworms!  Be sure to read more about Army cutworms.

Army cutworm larva (cc-by 3.0 Whitney Cranshaw, bugwood.org)


Several species of cutworms  can be present in fields.  They range in colour from shiny opaque, to tan, to brownish-red with chevron patterning.  Cutworm biology, species information, plus monitoring recommendations are available in the Prairie Pest Monitoring Network’s Cutworm Monitoring Protocol.  Also refer to the Manitoba Agriculture cutworm fact sheet which includes action and economic thresholds for cutworms in several crops. 

Keep an eye on fields that are “slow” to emerge, are missing rows, include wilting or yellowing plants, have bare patches, or appear highly attractive to birds – these are areas warranting a closer look.  Plan to follow-up by walking these areas later in the day when some cutworm species move above-ground to feed.  Start to dig below the soil surface (1-5 cm deep) near the base of a symptomatic plant or the adjacent healthy plant.  If the plant is well-established, check within the crown in addition to the adjacent soil.  The culprits could be wireworms or cutworms.  


For Albertans….. If you find cutworms, please consider using the Alberta Pest Surveillance Network’s “2017 Cutworm Reporting Tool”.  Once data entry occurs, growers can view the live 2017 cutworm map which is updated daily.


Remember the NEW Cutworm Field Guide is free and downloadable in 2017!

Weekly Update – Cereal leaf beetle

Cereal leaf beetle (Oulema melanopus) – As of May 15, 2017, the CLB model predicts that oviposition should be underway in the Lethbridge, Swift Current and Brandon areas. Compared to southern Alberta and Saskatchewan, populations in southern Manitoba are predicted to be delayed by approximately a week.

Lifecycle and Damage:
Adult: Adult cereal leaf beetles (CLB) have shiny bluish-black wing-covers (Fig. 1). The thorax and legs are light orange-brown. Females (4.9 to 5.5 mm) are slightly larger than the males (4.4 to 5 mm). Adult beetles overwinter in and along the margins of grain fields in protected places such as in straw stubble, under crop and leaf litter, and in the crevices of tree bark. They favour sites adjacent to shelter belts, deciduous and conifer forests. They emerge in the spring once temperature reaches 10-15 ºC and are active for about 6 weeks. They usually begin feeding on grasses, then move into winter cereals and later into spring cereals.  

Figure 1. Adult Oulema melanopus (~4.4-5.5 mm long).


Egg: Eggs are laid approximately 14 days following the emergence of the adults. Eggs are laid singly or in pairs along the mid vein on the upper side of the leaf and are cylindrical, measuring 0.9 mm by 0.4 mm, and yellowish in colour. Eggs darken to black just before hatching.  

Larva: The larvae hatch in about 5 days and feed for about 3 weeks, passing through 4 growth stages (instars). The head and legs are brownish-black; the body is yellowish. Larvae are usually covered with a secretion of mucus and fecal material, giving them a shiny black, wet appearance (Fig. 2).  When the larva completes its growth, it drops to the ground and pupates in the soil. 

Figure 2.  Larval stage of Oulema melanopus with characteristic feeding damage visible on leaf.



Pupa: Pupal colour varies from a bright yellow when it is first formed, to the colour of the adult just before emergence. The pupal stage lasts 2 – 3 weeks. Adult beetles emerge and feed for a couple of weeks before seeking overwintering sites. There is one generation per year.

Fact sheets for CLB are published by the province of Alberta and available from the Prairie Pest Monitoring Network. Also access the Oulema melanopus page from the new “Field crop and forage pests and their natural enemies in western Canada – Identification and management field guide”.

Weekly Update – Alfalfa weevil

Alfalfa Weevil (Hypera postica) – The larval stage of this weevil feeds on alfalfa leaves in a manner that characterizes the pest as a “skeletonizer”.  The green larva featuring a dorsal, white line down the length of its body has a dark brown head capsule and will grow to 9mm long.  Alfalfa growers are encouraged to check the Alfalfa Weevil Fact Sheet prepared by Dr. Julie Soroka (AAFC-Saskatoon).




Degree-day maps of base 9°C are now being produced by Soroka, Olfert, and Giffen (2016) using the Harcourt/North Dakota models.  Models predicting the development of Alfalfa weevil (Hypera postica) across the prairies are updated weekly to help growers time their in-field scouting for second-instar larvae.  Compare the following predicted development stages and degree-day values from Soroka (2015) to the map below.



This week, the predictive model output for Brooks AB suggests that oviposition is well underway (i.e., in areas of the map below highlighted chocolate-brown).  The initial first instar larvae may occur by next week.



Use the figure below as a visual reference to identify alfalfa weevil larvae.  Note the white dorsal line, the tapered shape of the abdomen and the dark head capsule.

Additional information can be accessed by reviewing the Alfalfa Weevil Page extracted from the “Field crop and forage pests and their natural enemies in western Canada – Identification and management field guide” (Philip et al. 2015).  The guide is available in both a free English-enhanced or French-enhanced version.

Weekly Update – Pea leaf weevil

Pea Leaf Weevil (Sitona lineatus– The pea leaf weevil simulation model will be used to monitor weevil development across the prairies. Weekly temperature data collected across the prairies is incorporated into the simulation model which calculates estimates of weevil development stages based on biological parameters for Sitona lineatus.


Model output predicted that flight of pea leaf weevil adults was significantly earlier in Lethbridge than Saskatoon in 2017.  In the figure below, note the red line predicting adults emerging from overwintering then the yellow line predicting overwintered adults taking flight this spring for Lethbridge AB (Fig. 1, Upper) and Saskatoon SK (Fig. 1, Lower).





Figure 1.  Model output predicting development of pea leaf weevil in Lethbridge AB (Upper) and Saskaton SK (Lower) in the spring of 2017.




Reminder – In 2016, the distribution of pea leaf weevil increased dramatically based on both damage assessments AND collection of adults in 2016 (Fig. 2).

Figure 2. Distribution of pea leaf weevil (Sitona lineatus) based on surveying conducted in 2016 (Olfert et al. 2017).




Pea leaf weevils emerge in the spring primarily by flying (at temperatures above 17ºC) or they may walk short distances. Pea leaf weevil movement into peas and faba beans is achieved primarily through flight.  Adults are slender, greyish-brown measuring approximately 5 mm in length (Fig. 3, Left).  


The pea leaf weevil resembles the sweet clover weevil (Sitona cylindricollis) but the former is distinguished by three light-coloured stripes extending length-wise down thorax and sometimes the abdomen.  All species of Sitona, including the pea leaf weevil, have a short snout.  



Figure 3.  Comparison images and descriptions of four Sitona species adults including pea leaf weevil (Left).


Adults will feed upon the leaf margins and growing points of legume seedlings (alfalfa, clover, dry beans, faba beans, peas) and produce a characteristic, scalloped (notched) edge.  Females lay 1000 to 1500 eggs in the soil either near or on developing pea or faba bean plants from May to June.


Biological and monitoring information related to pea leaf weevil in field crops is posted by the province of Alberta.  Also refer to the pea leaf weevil page within the “Field Crop and Forage Pests and their Natural Enemies in Western Canada: Identification and management field guide” – both English-enhanced or French-enhanced versions are available.  A review of this insect was published in 2011 in Prairie Soils and Crops by Carcamo and Vankosky.

Weekly Update – Predicted Grasshopper Development

Grasshopper Simulation Model Output – The grasshopper simulation model will be used to monitor grasshopper development across the prairies. Weekly temperature data collected across the prairies is incorporated into the simulation model which calculates estimates of grasshopper development stages based on biological parameters for Melanoplus sanguinipes (Migratory grasshopper).  


As of May 15, 2017, the predicted mean embryological development was only slightly ahead of last week at 66% (compared to 62% last week), and similar to long term averages (64%; Fig. 1). Although it is still early in the growing season, grasshopper hatch can vary across the prairies. For example, model output indicated that the hatch in Vauxhall AB was predicted to be about a week ahead of Saskatoon SK. As a result, timing of peak hatch could be 10-14 days earlier in Vauxhall than Saskatoon.


Figure 1.  Simulation model outputs mapped to predict the embryological development of Migratory grasshopper  (Melanoplus sanguinipes) eggs across the Canadian prairies as of May 15, 2017).


Reminder – The Prairie Pest Monitoring Network’s 2017 Grasshopper Forecast Map (Fig. 2) was released in January.  While spring temperatures, soil moisture conditions, and precipitation can all have an impact on overwintered grasshopper eggs, growers in areas highlighted orange or red in the map below should be vigilant as nymphs begin to hatch this season.

Figure 2. Prairie Pest Monitoring Network’s 2017 Grasshopper Forecast Map.


Biological and monitoring information related to grasshoppers in field crops is posted by Manitoba Agriculture, Food and Rural DevelopmentSaskatchewan AgricultureAlberta Agriculture and Forestry, the BC Ministry of Agriculture and the Prairie Pest Monitoring Network.  Also refer to the grasshopper pages within the new “Field Crop and Forage Pests and their Natural Enemies in Western Canada: Identification and management field guide” as an English-enhanced or French-enhanced version.

Weekly Update – Predicted Bertha Armyworm Development

Bertha armyworm (Lepidoptera: Mamestra configurata– The first map (Fig. 1) shows that predicted pupal development is well underway (average 27%)

Figure 1. Predicted stage of pupal development of overwintered Bertha armyworm set to emerge in 2017.



The second map (Fig. 2) indicates that predicted development this year is ahead of long term averages in Manitoba and Saskatchewan

Figure 2. Pupal development of overwintered Bertha armyworm in 2017 compared to long-term averages observed across the Canadian prairies.



These maps will be updated weekly to aid those who deploy and monitor this moth using pheromone traps.  The video below posted by Alberta Agriculture and Forestry’s Scott Meers describes how pheromone traps are used to monitor this important pest of canola.







Biological and monitoring information related to bertha armyworm in field crops is posted by the provinces of ManitobaSaskatchewanAlberta and the Prairie Pest Monitoring Network.  Also refer to the bertha armyworm pages within the new “Field Crop and Forage Pests and their Natural Enemies in Western Canada: Identification and management field guide” – both English-enhanced or French-enhanced versions are available.


Weekly Update – Scouting Charts (Canola and Flax)

Field scouting is critical – it enables the identification of potential risks to crops.  However, the identification of these insect pests PLUS the application of established monitoring methods will enable growers to make informed pest management decisions.


For 2017, we offer TWO generalized insect pest scouting charts to aid in-field scouting on the Canadian prairies:

1. CANOLA INSECT SCOUTING CHART

    

2. A NEW FLAX INSECT SCOUTING CHART

    
These charts feature hyperlinks directing growers to downloadable PDF pages within the “Field crop and forage pests and their natural enemies in western Canada: Identification and management field guide“.


Whenever possible, monitor and compare pest densities to established economic or action thresholds to protect and preserve pollinators and beneficial arthropods. Economic thresholds, by definition, help growers avoid crop losses related to outbreaking insect pest species.


Good luck with your scouting!

Weekly Update – Flea beetles

Flea Beetles (Chrysomelidae: Phyllotreta species) – Be on the lookout for flea beetle damage resulting from feeding on canola cotyledons but also on the stem.



Remember, the Action Threshold for flea beetles on canola is 25% of cotyledon leaf area consumed.  Shot-hole feeding is the traditional damage in seedling canola but watch the growing point and stems of seedlings.

Refer to the flea beetle page from the new “Field Crop and Forage Pests and their Natural Enemies in Western Canada: Identification and management field guide” as an English-enhanced or French-enhanced version.

Weekly Update – Cutworms

Cutworms (Noctuidae) – NEW – Just in time for spring scouting!  A new field guide is now available to help growers scout and manage Cutworms!  Cutworm Pest of Crops is now available for free in either English or French and is featured at our new Cutworm Field Guide!  Also be sure to check the Insect of the Week throughout May – it highlights cutworms!  Be sure to read more about Redbacked cutworms.

Figure 1. Redbacked cutworms retrieved from a Manitoban field (Photo: J. Gavloski)

Several species of cutworms  can be present in fields.  They range in colour from shiny opaque, to tan, to brownish-red with chevron patterning.  Cutworm biology, species information, plus monitoring recommendations are available in the Prairie Pest Monitoring Network’s Cutworm Monitoring Protocol.  Also refer to the Manitoba Agriculture cutworm fact sheet which includes action and economic thresholds for cutworms in several crops. 

Keep an eye on fields that are “slow” to emerge, are missing rows, include wilting or yellowing plants, have bare patches, or appear highly attractive to birds – these are areas warranting a closer look.  Plan to follow-up by walking these areas later in the day when some cutworm species move above-ground to feed.  Start to dig below the soil surface (1-5 cm deep) near the base of a symptomatic plant or the adjacent healthy plant.  If the plant is well-established, check within the crown in addition to the adjacent soil.  The culprits could be wireworms or cutworms.  

For Albertans….. If you find cutworms, please consider using the Alberta Pest Surveillance Network’s “2017 Cutworm Reporting Tool”.  Once data entry occurs, growers can view the live 2017 cutworm map which is updated daily.


Remember the NEW Cutworm Field Guide is free and downloadable in 2017!

Weekly Update – Cereal leaf beetle

Cereal leaf beetle (Oulema melanopus) – As
of May 8, 2017, CLB model output predicted that oviposition is underway in populations
that may be present in the Lethbridge, Swift Current and Brandon areas. Compared
to 2016, phenological development in 2017 is approximately 1 week later.

Lifecycle and Damage:
Adult: Adult cereal leaf beetles (CLB) have shiny bluish-black wing-covers (Fig. 1). The thorax and legs are light orange-brown. Females (4.9 to 5.5 mm) are slightly larger than the males (4.4 to 5 mm). Adult beetles overwinter in and along the margins of grain fields in protected places such as in straw stubble, under crop and leaf litter, and in the crevices of tree bark. They favour sites adjacent to shelter belts, deciduous and conifer forests. They emerge in the spring once temperature reaches 10-15 ºC and are active for about 6 weeks. They usually begin feeding on grasses, then move into winter cereals and later into spring cereals.  

Figure 1. Adult Oulema melanopus (~4.4-5.5 mm long).


Egg: Eggs are laid approximately 14 days following the emergence of the adults. Eggs are laid singly or in pairs along the mid vein on the upper side of the leaf and are cylindrical, measuring 0.9 mm by 0.4 mm, and yellowish in colour. Eggs darken to black just before hatching.  

Larva: The larvae hatch in about 5 days and feed for about 3 weeks, passing through 4 growth stages (instars). The head and legs are brownish-black; the body is yellowish. Larvae are usually covered with a secretion of mucus and fecal material, giving them a shiny black, wet appearance (Fig. 2).  When the larva completes its growth, it drops to the ground and pupates in the soil. 

Figure 2.  Larval stage of Oulema melanopus with characteristic feeding damage visible on leaf.



Pupa: Pupal colour varies from a bright yellow when it is first formed, to the colour of the adult just before emergence. The pupal stage lasts 2 – 3 weeks. Adult beetles emerge and feed for a couple of weeks before seeking overwintering sites. There is one generation per year.

Fact sheets for CLB are published by the province of Alberta and available from the Prairie Pest Monitoring Network. Also access the Oulema melanopus page from the new “Field crop and forage pests and their natural enemies in western Canada – Identification and management field guide”.

Weekly Update – Pea leaf weevil

Pea Leaf Weevil (Sitona lineatus– This species was one of the “big” insects of 2016’s field crop growing season.  The distribution of pea leaf weevil increased dramatically based on both damage assessments AND collection of adults in 2016 (Fig. 1) compared to previous years (Fig. 2).

Figure 1. Distribution of pea leaf weevil (Sitona lineatus) based on surveying conducted in 2016 (Olfert et al. 2017).


Figure 2.  Distributions of pea leaf weevil based on surveying conducted between 2012-2015 (Olfert et al. 2017).



Pea leaf weevils emerge in the spring primarily by flying (at temperatures above 17ºC) or they may walk short distances. Pea leaf weevil movement into peas and faba beans is achieved primarily through flight.  Adults are slender, greyish-brown measuring approximately 5 mm in length (Fig. 3, Left).  

The pea leaf weevil resembles the sweet clover weevil (Sitona cylindricollis) but the former is distinguished by three light-coloured stripes extending length-wise down thorax and sometimes the abdomen.  All species of Sitona, including the pea leaf weevil, have a short snout.  

Figure 3.  Comparison images and descriptions of four Sitona species adults including pea leaf weevil (Left).


Adults will feed upon the leaf margins and growing points of legume seedlings (alfalfa, clover, dry beans, faba beans, peas) and produce a characteristic, scalloped (notched) edge.  Females lay 1000 to 1500 eggs in the soil either near or on developing pea or faba bean plants from May to June.


Biological and monitoring information related to pea leaf weevil in field crops is posted by the province of Alberta.  Also refer to the pea leaf weevil page within the “Field Crop and Forage Pests and their Natural Enemies in Western Canada: Identification and management field guide” – both English-enhanced or French-enhanced versions are available.  A review of this insect was published in 2011 in Prairie Soils and Crops by Carcamo and Vankosky.

Weekly Update – Predicted Grasshopper Development

Grasshopper Simulation Model Output – The grasshopper simulation model will be used to monitor grasshopper development across the prairies. Weekly temperature data collected across the prairies is incorporated into the simulation model which calculates estimates of grasshopper development stages based on biological parameters for Melanoplus sanguinipes (Migratory grasshopper).  


As of May 8, 2017, predicted mean embryological development was 62% (56% last week); the greatest development was predicted to be across southern Saskatchewan. Embryological development was very similar to long term averages (60%) though well behind 2016 (74%). Hatch was not predicted for any locations. 

Reminder – The Prairie Pest Monitoring Network’s 2017 Grasshopper Forecast Map (Figure 1) was released in January.  While spring temperatures, soil moisture conditions, and precipitation can all have an impact on overwintered grasshopper eggs, growers in areas highlighted orange or red in the map below should be vigilant as nymphs begin to hatch this season.

Figure 1. Prairie Pest Monitoring Network’s 2017 Grasshopper Forecast Map.


Biological and monitoring information related to grasshoppers in field crops is posted by Manitoba Agriculture, Food and Rural DevelopmentSaskatchewan AgricultureAlberta Agriculture and Forestry, the BC Ministry of Agriculture and the Prairie Pest Monitoring Network.  Also refer to the grasshopper pages within the new “Field Crop and Forage Pests and their Natural Enemies in Western Canada: Identification and management field guide” as an English-enhanced or French-enhanced version.

Weekly Update – Scouting Charts (Canola and Flax)

Field scouting is critical – it enables the identification of potential risks to crops.  Field crop production systems across the Canadian prairies will suffer insect pest outbreaks.  However, the identification of these insect pests PLUS the application of established monitoring methods will enable growers to make informed pest management decisions.

For 2017, we offer TWO generalized insect pest scouting charts to aid in-field scouting on the Canadian prairies:


1. CANOLA INSECT SCOUTING CHART
   



2. A NEW FLAX INSECT SCOUTING CHART
    

These charts feature hyperlinks directing growers to downloadable PDF pages within the “Field crop and forage pests and their natural enemies in western Canada: Identification and management field guide“.

Growers can access biological information about the pest and its natural enemies, the type of damage it causes, how to monitor, and what pest management strategies might apply to help protect yield and quality (Fig. 1).

Whenever possible, monitor and compare pest densities to established economic or action thresholds to protect and preserve pollinators and beneficial arthropods. Economic thresholds, by definition, help growers avoid crop losses related to outbreaking insect pest species.

Good luck with your scouting!

Figure 1. Example of Bertha armyworm pages from the above field guide:

Weekly Update – Predicted Grasshopper Development

Grasshopper Simulation Model Output – The grasshopper simulation model will be used to monitor grasshopper development across the prairies. Weekly temperature data collected across the prairies is incorporated into the simulation model which calculates estimates of grasshopper development stages based on biological parameters for Melanoplus sanguinipes (Migratory grasshopper).  


As of May 1, 2017, model output predicted embryological mean development was 56%; the greatest development was predicted to be across the southern prairies. Embryological development was very similar to long term averages (57%) though marginally slower than 2016 (62%).


Reminder – The Prairie Pest Monitoring Network’s 2017 Grasshopper Forecast Map (Figure 1) was released in January.  While spring temperatures, soil moisture conditions, and precipitation can all have an impact on overwintered grasshopper eggs, growers in areas highlighted orange or red in the map below should be vigilant as nymphs begin to hatch this season.

Figure 1. Prairie Pest Monitoring Network’s 2017 Grasshopper Forecast Map.



Biological and monitoring information related to grasshoppers in field crops is posted by Manitoba Agriculture, Food and Rural DevelopmentSaskatchewan AgricultureAlberta Agriculture and Forestry, the BC Ministry of Agriculture and the Prairie Pest Monitoring Network.  Also refer to the grasshopper pages within the new “Field Crop and Forage Pests and their Natural Enemies in Western Canada: Identification and management field guide” as an English-enhanced or French-enhanced version.

Weekly Update – Grasshoppers

Grasshoppers (Acrididae) – Previous model predictions related to hatch and nymphal instar development can be reviewed here.  


The following image showing various stages of Camnulla pellucida is provided below – note that adults have wings extending the length of the abdomen whereas nymphs lack wings but develop wing buds that will eventually mature to wings.  


Generally, the economic threshold for grasshoppers in cereals is 8-12 per square metre but will vary by crop and growing conditions.

Figure 1. Life stages of Camnulla pellucida which including eggs, first-fifth instar nymphs and adult (L-R).
Biological and monitoring information related to grasshoppers in field crops is posted by the provinces of ManitobaSaskatchewanAlbertaBritish Columbia and the Prairie Pest Monitoring Network.  Also refer to the grasshopper pages within the new “Field Crop and Forage Pests and their Natural Enemies in Western Canada: Identification and management field guide” – both English-enhanced or French-enhanced versions are available.

Weekly Update – Swede midge

Swede midge (Contarinia nasturtii)  – Reminder – Pheromone traps captured the first swede midge of 2016 between May 25 and 31 in northeastern Saskatchewan.  This is substantially earlier (6-7 weeks) compared to 2014 and 2015. 

The earlier emergence pattern is likely due to the mild winter and warm spring weather combined with adequate moisture levels. Emergence traps indicate a moderate number of swede midge have emerged near Carrot River, Saskatchewan, and producers should monitor their canola fields for damage symptoms

Figure 1. Swede midge infested canola buds which are enlarged with sepals fused together. 


Figure 2.  Swede midge large (~1mm long; yellowish-white) feeding within canola flower.


Swede midge scouting tips for in-field monitoring:
• Watch for unusual plant structures and plant discolourations then follow-up by closely scrutinizing the plant for larvae.
• The growing tip may become distorted and produce several growing tips or none at all, young leaves may become swollen, crinkled or crumpled and brown scarring caused by larval feeding may be seen on the leaf petioles and stems.
• Flowers may fail to open.
• Young plants that show unusual growth habits should be examined carefully for damage and larvae; especially if the sticky liners have many flies resembling midges (swede midges are about the size of orange blossom wheat midge but are not orange).
• Larvae can be seen with a hand lens.
• Refer to the Canola Watch article by Dr. Julie Soroka for more information on swede midge and watch for a new Ontario fact sheet produced by Baute et al. 2016.

Note the distribution map of confirmed symptoms and populations of swede midge (red dots) on the Canadian prairies  (Soroka and Andreassen 2015).


Weekly Update – Grasshoppers

Grasshoppers (Acrididae) – Previous model predictions related to hatch and nymphal instar development can be reviewed here.  

For the week of June 19, 2016, warm conditions in southeastern Saskatchewan and southern Manitoba were predicted to result in enhanced grasshopper development. Across the prairies, grasshoppers should be between the first and fifth instars. The model predicted that approximately 15% of the population was predicted to be in the first instar, 35% second, 28% third, 13% fourth instar and just under one percent fifth instar.  Development is well ahead of average rates (22% first instar, 14% second instar and 10% third instar). 



In central Saskatchewan, grasshopper development is currently more than two weeks ahead of average development. The following graph shows grasshopper development at Saskatoon based on 2016 data. The model indicates that fifth instar grasshoppers should be present.





Now compare the above with the following graph which illustrates grasshopper development (for Saskatoon) based on long term normal (LTN) data.  The model indicates that  primarily first instars are predicted to be present with only the initial appearance of third instar nymphs. 



The following image showing various stages of the clearwinged grasshopper is provided below – note that adults have wings extending the length of the abdomen whereas nymphs lack wings but develop wing buds that will eventually mature to wings.  


Figure 1. Life stages of Camnulla pellucida  which including eggs, first-fifth instar nymphs and adult (L-R).


Biological and monitoring information related to grasshoppers in field crops is posted by the provinces of ManitobaSaskatchewanAlbertaBritish Columbia and the Prairie Pest Monitoring Network.  Also refer to the grasshopper pages within the new “Field Crop and Forage Pests and their Natural Enemies in Western Canada: Identification and management field guide” – both English-enhanced or French-enhanced versions are available.

Weekly Update – Swede midge

Swede midge (Contarinia nasturtii)  – Reminder – Pheromone traps captured the first swede midge of 2016 between May 25 and 31 in northeastern Saskatchewan.  This is substantially earlier (6-7 weeks) compared to 2014 and 2015. 


The earlier emergence pattern is likely due to the mild winter and warm spring weather combined with adequate moisture levels. Emergence traps indicate a moderate number of swede midge have emerged near Carrot River, Saskatchewan, and producers should monitor their canola fields for damage symptoms

Figure 1. Swede midge infested canola buds which are enlarged with sepals fused together. 




Figure 2.  Swede midge large (~1mm long; yellowish-white) feeding within canola flower.



Swede midge scouting tips for in-field monitoring:
• Watch for unusual plant structures and plant discolourations then follow-up by closely scrutinizing the plant for larvae.
• The growing tip may become distorted and produce several growing tips or none at all, young leaves may become swollen, crinkled or crumpled and brown scarring caused by larval feeding may be seen on the leaf petioles and stems.
• Flowers may fail to open.
• Young plants that show unusual growth habits should be examined carefully for damage and larvae; especially if the sticky liners have many flies resembling midges (swede midges are about the size of orange blossom wheat midge but are not orange).
• Larvae can be seen with a hand lens.
• Refer to the Canola Watch article by Dr. Julie Soroka for more information on swede midge and watch for a new Ontario fact sheet produced by Baute et al. 2016.




Note the distribution map of confirmed symptoms and populations of swede midge (red dots) on the Canadian prairies  (Soroka and Andreassen 2015).



Weekly Update – Cabbage seedpod weevil

Cabbage seedpod weevil (Ceutorhynchus obstrictus–  There is one generation of CSPW per year and the overwintering stage is the adult which is an ash-grey weevil measuring 3-4mm long (Refer to lower left photo).  Adults typically overwinter in soil beneath leaf litter within shelter belts and roadside ditches.


CSPW emerge from overwintering in the spring as soil temperatures warm to ~15°C.  CSPW utilize several flowering hosts including wild mustard, flixweed, hoary cress, stinkweed and volunteer canola.  CSPW move to canola during the bud to early flower stages and will feed on pollen and buds, causing flowers to die.


The map below reflects CSPW densities observed in 2015.  Growers situated within or adjacent to areas of the map highlighted yellow, orange and red will need to be scouting with a sweep-net as their canola fields initiate flowering.






Monitoring:  
 ● Begin sampling when the crop first enters the bud stage and continue through the flowering. 
 ● Sweep-net samples should be taken at ten locations within the field with ten 180° sweeps per location.  
 ● Count the number of weevils at each location. Samples should be taken in the field perimeter as well as throughout the field.  
 ● Adults will invade fields from the margins and if infestations are high in the borders, application of an insecticide to the field margins may be effective in reducing the population to levels below which economic injury will occur.  
 ● An insecticide application is recommended when three to four weevils per sweep are collected and has been shown to be the most effective when canola is in the 10 to 20% bloom stage (2-4 days after flowering starts). 
 ● Consider making insecticide applications late in the day to reduce the impact on pollinators.  Whenever possible, provide advanced warning of intended insecticide applications to commercial beekeepers operating in the vicinity to help protect foraging pollinators.  
 ● High numbers of adults in the fall may indicate the potential for economic infestations the following spring.

Damage: Adult feeding damage to buds is more evident in dry years when canola is unable to compensate for bud loss.  Adults mate following a pollen meal then the female will deposit a single egg through the wall of a developing pod or adjacent to a developing seed within the pod (refer to lower right photo).  Eggs are oval and an opaque white, each measuring ~1mm long.  Typically a single egg is laid per pod although, when CSPW densities are high, two or more eggs may be laid per pod.


There are four larval instar stages of the CSPW and each stage is white and grub-like in appearance ranging up to 5-6mm in length (refer to lower left photo).  The first instar larva feeds on the cuticle on the outside of the pod while the second instar larva bores into the pod, feeding on the developing seeds.  A single larva consumes about 5 canola seeds.  The mature larva chews a small, circular exit hole from which it drops to the soil surface and pupation takes place in the soil within an earthen cell.  Approximately 10 days later, the new adult emerges to feed on maturing canola pods.  Later in the season these new adults migrate to overwintering sites beyond the field.



Please find additional detailed information for CSPW in fact sheets posted by Alberta Agriculture and ForestrySaskatchewan Agriculture, or the Prairie Pest Monitoring Network.

Weekly Update – Alfalfa weevil

Alfalfa Weevil (Hypera postica)  Earlier predictive model outputs can be reviewed by searching the Blog for “Alfalfa weevil” or use the Label Index located to the right of the screen to sort and review all “Alfalfa weevil” posts for 2016.


Reminder – The larval stage of this weevil feeds on alfalfa leaves in a manner that characterizes the pest as a “skeletonizer”.  The green larva featuring a dorsal, white line down the length of its body has a dark brown head capsule and will grow to 9mm long.  Alfalfa growers are encouraged to check the Alfalfa Weevil Fact Sheet prepared by Dr. Julie Soroka (AAFC-Saskatoon).




Economic thresholds for Alfalfa weevil (adapted from Soroka 2015) vary by crop type (hay or seed), area fed upon and larval densities.

In hay fields, forage losses can be economic if one or more of the following symptoms are noted:
● if 25-50 % of the leaves on the upper one-third of the stem show damage, or
● if 50-70% of the terminals are injured, or
● if 1 to 3 third or fourth instar larvae occur per stem (with shorter stems having lower economic thresholds and 3 or more larvae requiring treatment no matter what the alfalfa height), or 
● 20-30 larvae per sweep occur when 12% leaf loss is acceptable.
● Also consider these two points:
      1. Early cutting of the first growth of alfalfa or insecticide treatment will reduce alfalfa weevil populations.
      2. If the hay crop value is high and weevil injury is seen or 2 or more larvae per stem reappear in regrowth after cutting, insecticide may be necessary (if a second cut is anticipated). 


In alfalfa seed fields:
● Economic thresholds are 20-25 third to fourth instar larvae per sweep or 35-50% of the foliage tips showing damage. 
● Thresholds increase with the height of the alfalfa, and decrease in drought conditions. 
● Also know that several small wasps parasitize alfalfa weevil larvae and adults, and in the past these natural control agents kept the weevil in check in most years. One of these wasps, Bathyplectes curculionis (Thomson), parasitizes alfalfa weevil in Alberta and Saskatchewan, and is now found in Manitoba.

Weekly Update – Grasshoppers

Grasshoppers (Acrididae) – Previous model predictions related to hatch and nymphal instar development can be reviewed here.  

Reminder – Weekly surveying conducted by AAFC-Saskatoon Staff on June 2, 2016, confirmed that Melanoplines were primarily first and second instar stages although a few third instar nymphs were collected.

The following image showing various stages of the clearwinged grasshopper is provided below – note that adults have wings extending the length of the abdomen whereas nymphs lack wings but develop wing buds that will eventually mature to wings.  

Biological and monitoring information related to grasshoppers in field crops is posted by the provinces of ManitobaSaskatchewanAlbertaBritish Columbia and the Prairie Pest Monitoring Network.  Also refer to the grasshopper pages within the new “Field Crop and Forage Pests and their Natural Enemies in Western Canada: Identification and management field guide” – both English-enhanced or French-enhanced versions are available.

Weekly Update – Cutworms

Cutworms (Noctuidae) – The past week, cutworms were reported across Manitoba, Saskatchewan and Alberta.  


Keep an eye on fields that are “slow” to emerge, are missing rows, include wilting or yellowing plants, have bare patches, or appear highly attractive to birds – these are areas warranting a closer look.  Plan to follow-up by walking these areas later in the day when some cutworm species move above-ground to feed.  Start to dig below the soil surface (1-5 cm deep) near the base of a symptomatic plant or the adjacent healthy plant.  If the plant is well-established, check within the crown in addition to the adjacent soil.  The culprits could be wireworms or cutworms.  

Several species of cutworms  can be present in fields.  They range in colour from shiny opaque, to tan, to brownish-red with chevron patterning.  Cutworm biology, species information, plus monitoring recommendations are available in the Prairie Pest Monitoring Network’s Cutworm Monitoring Protocol.  Also refer to Manitoba Agriculture and Rural Initiatives cutworm fact sheet which includes action and economic thresholds for cutworms in several crops. 

More information about cutworms can be found by accessing the pages from the new “Field Crop and Forage Pests and their Natural Enemies in Western Canada: Identification and Field Guide”.  View an excerpt of ONLY the Cutworm pages from the new “Field Crop and Forage Pests and their Natural Enemies in Western Canada: Identification and management field guide”.  The guide is available as a free downloadable document as both an English-enhanced or French-enhanced version.


For Manitobans….The  earlier Insect Update included great photos of dingy and redbacked cutworms plus monitoring tips including how to discern these two species from one another.  Reports of cutworm continued in the most recent Insect Update.


For Saskatchewanians…. Cutworms were reported in the recent Saskatchewan Insect Report.

For Albertans….. Additional reports of cutworms have occurred throughout the province the past week!  If you find cutworms, please consider using the Alberta Pest Surveillance Network’s “2016 Cutworm Reporting Tool”.  Once data entry occurs, your growers can view the live 2016 cutworm map.

A screen shot of the live map has been retrieved (06Jun2016) below for your reference.

Weekly Update – Alfalfa weevil

Alfalfa Weevil (Hypera postica) – The larval stage of this weevil feeds on alfalfa leaves in a manner that characterizes the pest as a “skeletonizer”.  The green larva featuring a dorsal, white line down the length of its body has a dark brown head capsule and will grow to 9mm long.  Alfalfa growers are encouraged to check the Alfalfa Weevil Fact Sheet prepared by Dr. Julie Soroka (AAFC-Saskatoon).

Updated – Degree-day maps of base 9°C are now being produced by Soroka, Olfert, and Giffen (2016) using the Harcourt/North Dakota models.  The aim or the modelling is to predict the development of Alfalfa weevil (Hypera postica) across the prairies and to help growers time their in-field scouting as second-instar larvae are predicted to occur.  Compare the following predicted development stages and degree-day values copied below (Soroka 2015) to the map below.





For the week of June 5, 2016, second instar larvae are predicted to be present in fields falling within areas of the map highlighted ANY shade of purple.  Third and fourth instar larvae are predicted to be present in fields falling within areas highlighted ANY shade of blue in the map below.  Scout field and compare larval densities to the action threshold for alfalfa weevil which varies according to end use and crop stage.  



Weekly Update – Predicted Grasshopper Development

Grasshoppers (Acrididae) – Warm temperatures in Saskatchewan and southern Manitoba were predicted to result in enhanced development. 


The model predicted that 41% of the hatch is complete (versus 23% last week)


Approximately 25% of the population was predicted to be in the first instar whereas 11% were predicted to be in the second instar.  Development is well ahead of average rates (9% hatch, 7% first instar and 2% second instar). 






Weekly surveying conducted by AAFC-Saskatoon Staff on June 2, 2016, confirmed that Melanoplines were primarily first and second instar stages although a few third instar nymphs were collected.

The following image showing various stages of the clearwinged grasshopper is provided below – note that adults have wings extending the length of the abdomen whereas nymphs lack wings but develop wing buds that will eventually mature to wings.  




Biological and monitoring information related to grasshoppers in field crops is posted by the provinces of ManitobaSaskatchewanAlbertaBritish Columbia and the Prairie Pest Monitoring Network.  Also refer to the grasshopper pages within the new “Field Crop and Forage Pests and their Natural Enemies in Western Canada: Identification and management field guide” – both English-enhanced or French-enhanced versions are available.

Weekly Update – Canola scouting chart

We again post our generalized canola scouting chart to aid in-field scouting on the Canadian prairies. The version below contains hyperlinks to help growers learn more about some of our insect pests and how to monitor for them. 

Weekly Update – Flea beetles

Reminder – Flea Beetles (Chrysomelidae: Phyllotreta species) – Remember, the Action Threshold for flea beetles on canola is 25% of cotyledon leaf area consumed.  Shot-hole feeding is the traditional damage in seedling canola but watch the growing point and stems of seedlings.

Estimating flea beetle feeding damage can be challenging.  Using a visual guide to estimate damage can be helpful.  Canola Watch circulated this article but also use the images (copied below for reference) produced by Dr. J. Soroka (AAFC-Saskatoon)  – take  them scouting!

Figure 1. Canola cotyledons with various percentages of leaf area consume owing to flea beetle feeding damage (Photo: Soroka & Underwood, AAFC-Saskatoon).


Figure 2.  Percent leaf area consumed by flea beetles feeding on canola seedlings (Photo: Soroka & Underwood, AAFC-Saskatoon).

Refer to the flea beetle page from the new “Field Crop and Forage Pests and their Natural Enemies in Western Canada: Identification and management field guide” as an English-enhanced or French-enhanced version.

Also refer to the previous Flea beetle post on the Blog.

Weekly Update – Alfalfa weevil

Alfalfa Weevil (Hypera postica) – The larval stage of this weevil feeds on alfalfa leaves in a manner that characterizes the pest as a “skeletonizer”.  The green larva featuring a dorsal, white line down the length of its body has a dark brown head capsule and will grow to 9mm long.  Alfalfa growers are encouraged to check the Alfalfa Weevil Fact Sheet prepared by Dr. Julie Soroka (AAFC-Saskatoon).

Degree-day maps of base 9°C are now being produced by Soroka, Olfert, and Giffen (2016) using the Harcourt/North Dakota models.  The aim or the modelling is to predict the development of Alfalfa weevil (Hypera postica) across the prairies and to help growers time their in-field scouting as second-instar larvae are predicted to occur.  Compare the following predicted development stages and degree-day values copied below (Soroka 2015) to the map below.


This week, alfalfa growers situated within ANY shade of purple should prioritize scouting for second instar larvae and compare it to the action threshold for alfalfa weevil which varies according to end use and crop stage.  



Use the figure below as a visual reference to identify alfalfa weevil larvae.  Note the white dorsal line, the tapered shape and the dark head capsule.


Weekly Update – Predicted Bertha Armyworm Development

Bertha armyworm (Lepidoptera: Mamestra configurata– Bertha armyworm (BAW) pupal development is progressing well.  Pheromone traps should be deployed in areas highlighted yellow in the map below.


Those monitoring BAW pheromone traps may want to compare trap “catches” to the following reference photo kindly shared by Saskatchewan Agriculture below: