Insect of the Week – Army cutworm

Jennifer Otani
Categories
Week 3

For many, seed isn’t even in the ground yet, but the cutworms are ready for it when it is. So the time to start scouting for cutworms is now! Even if it is too wet to seed, consider checking volunteer plants for cutworms or feeding damage. General cutworm monitoring protocols can be found on the Monitoring Protocols page. Species-specific protocols can be found in the new Cutworm Pests of Crops on the Canadian Prairies (see below for download details).


There are over 20 cutworm species that may cause economic damage to your crop, each with different feeding behaviour, preferred hosts and lifecycle. This is why species identification is so important: it helps growers understand what they are up against: determining how and when to scout, knowing whether the cutworm species is found above-ground (climbing) or below-ground, recognizing damage, choosing control options. Species also impacts the most appropriate time of day for monitoring and applying controls.


Action and economic thresholds do exist for many of the cutworm species – please use them. This will help control costs by eliminating unnecessary/un-economic sprays and reduce your impact on non-target insects – insects that include cutworm natural enemies that work in the background to control cutworm populations.


This week’s Insect of the Week is the army cutworm. This is an above ground species. Young larvae chew holes in leaves and notch leaf margins. Older larvae will consume entire leaves. They get their name from the fact that when food is scarce, larvae move as a large group in the same direction to locate more host plants.


For more information about army cutworms, go to the Insect of Week page.

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

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

Weekly Update – Weather Synopsis

Ross Weiss, Owen Olfert, David Giffen and prairiepest_admin
Categories
Week 3

Weather synopsis – This week’s average temperatures were approximately 2°C cooler than normal and seven-day precipitation accumulations were above normal.  

Over the past month, precipitation was below average in Manitoba, but above average in northwest Alberta.


The map below reflects the Accumulated Precipitation for the Growing Season so far for the prairie provinces (i.e., April 1-May 17, 2017):


The map below shows the Lowest Temperatures the Past 7 Days (May 11-17, 2017) across the prairies:


Whereas the map below shows the Highest Temperatures the Past 7 Days (May 11-17, 2017):



The updated growing degree day map (GDD) (Base 5ºC, March 1 – May 14, 2017) is below:



While the growing degree day map (GDD) (Base 10ºC, March 1 – May 14, 2017) is below:


The maps above are all produced by Agriculture and Agri-Food Canada.  Growers may wish to bookmark the AAFC Drought Watch Maps for the growing season.

Wind Trajectories

Owen Olfert, David Giffen, Ross Weiss, Serge Trudel and prairiepest_admin
Categories
Week 3

THE WEEK OF MAY 15, 2017:  Wind trajectory data processing by AAFC-Saskatoon Staff began in April.  Reverse Trajectories track arriving air masses back to their point of origin while Forward Trajectories predict favourable winds expected to arrive across the Canadian Prairies for the week of May 15, 2017:

Reverse trajectories (RT)

Wind trajectories have been monitored since April 1 this year.  Wind patterns continue to be similar to previous weeks. The first graph (Fig. 1) indicates that winds from the Pacific Northwest (PNW) passed over Carman MB each day of the past week. Though the number of RTs increased over the past week, the overall pattern  has not changed across the prairies. 

Figure 1. Number of Reverse Trajectories (RT) originating in the Pacific Northwest that have arrived at sites across the Canadian prairies from May 9-15, 2017.



Figure 2 shows that the greatest number of RTs continue to be settling at sites across southern Alberta (e.g., areas highlighted red).

Figure 2.  Total number of reverse trajectories originating from the Pacific Northwest of the USA arriving at sites across the Canadian prairies (April 1-May 15, 2017).

Weekly Update – Flea beetles

Jennifer Otani
Categories
Week 3

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

Jennifer Otani
Categories
Week 3

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

Jennifer Otani
Categories
Week 3

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

David Giffen and prairiepest_admin
Categories
Week 3

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

Ross Weiss, Owen Olfert and Meghan Vankosky
Categories
Week 3

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

Ross Weiss, David Giffen, Owen Olfert and prairiepest_admin
Categories
Week 3

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

Ross Weiss, Owen Olfert and prairiepest_admin
Categories
Week 3

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)

Jennifer Otani
Categories
Week 3

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!

Crop reports

Jennifer Otani
Categories
Week 3

Crop reports are produced by:
• Manitoba Agriculture, Rural Development (May 15, 2017)
• Saskatchewan Agriculture Crop Report (May 9-15, 2017)
• Alberta Agriculture and Forestry Crop Report (May 9, 2017)


International reports are produced by:
• The United States Department of Agriculture’s Crop Progress Report (May 15, 2017)

• The European Commission’s Monitoring Agricultural ResourceS (MARS) bulletins for March 2017 can be accessed  and include outlooks for Russia, Kazakhstan, Turkey, Ukraine, and North Africa.

Provincial Insect Pest Reports

John Gavloski, Scott Meers and Scott Hartley
Categories
Week 3

Provincial entomologists provide insect pest updates throughout the growing season so we have attempted to link to their most recent information: 


Manitoba’s Insect and Disease Update for 2017 will be posted soon. Watch for updates prepared by John Gavloski and Pratisara Bajracharya).

Saskatchewan’s Crop Production News for 2017 will be posted soon. Watch for updates prepared by Scott Hartley and Danielle Stephens.  

Watch for Alberta Agriculture and Forestry’s Call of the Land for updates from Scott Meers who recently provided an update (posted on May 18, 2017). Flea beetles and seed-feeding carabids and fungus beetles in harvested grain were noted as being insects to watch at this point in Alberta.

Weekly Update – Monarch migration

Jennifer Otani
Categories
Week 3

We again track the migration of the Monarch butterflies as they move north by checking the 2017 Monarch Migration Map!  A screen shot of the map has been placed below as an example (retrieved 18May2017) but follow the hyperlink to check the interactive map!  They’ve migrated into the extreme south of Ontario! 



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