Weekly Update

Jennifer Otani, Ross Weiss, David Giffen, Serge Trudel, Kelly Turkington, Erl Svendsen, Owen Olfert and Meghan Vankosky
Categories
Week 10

Hello!

A special thanks ALWAYS to David Giffen (AAFC-Saskatoon) for all his work supporting the PPMN!  We are especially grateful this week for his keen eye!  David detected an issue with the incoming environmental data and, once again, steered us all in the right direction! 

Things are getting busy now for our field research programs so, from now until mid-July, the Weekly Update may need to be posted each week in portions at any point from Wednesday-Saturday.  Please bookmark the Blog or subscribe to receive the latest growing season information!

Please access the complete Weekly Update either as a series of Posts for Week 10 (June 13, 2019) OR a downloadable PDF. Be sure to check out the Insect of the Week – the rest of the growing season features doppelgangers to aid in-field scouting!

Questions or problems accessing the contents of this Weekly Update?  Please e-mail either Dr. Meghan Vankosky or Jennifer Otani.  Past “Weekly Updates” can be accessed on our Weekly Update page.

Subscribe to the Blog by following these easy steps!

Weather synopsis

Ross Weiss, David Giffen and Meghan Vankosky
Categories
Week 10

This week there was an issue with the incoming environmental data but it was thankfully detected by David Giffen (AAFC-Saskatoon).  

A: TEMPERATURES – Temperatures continued to be cooler than average. This past week temperatures were coolest in AB and warmest in MB (Fig. 1). Average temperatures for May 12 to June 11, 2019, were approximately 1°C cooler than average (Fig. 2).   

Figure 1.  Average temperature (°C) across the Canadian prairies over the past SEVEN days (June 5-11, 2019).
Figure 2.  Average temperature (°C) across the Canadian prairies over the past 30 days (May 12-June 11, 2019).
Figure 3.  Percent of Average precipitation across the Canadian prairies for the growing season (April 1-June 13, 2019).
Image has not been reproduced in affiliation with, or with the endorsement of the Government of Canada and was retrieved (14Jun2019).  Access the full map at http://www.agr.gc.ca/DW-GS/current-actuelles.jspx?lang=eng&jsEnabled=true

The growing degree day map (GDD) (Base 5 ºC, April 1-June 10, 2019) is below (Fig. 4):

Figure 4. Growing degree day (Base 5 ºC) across the Canadian prairies for the growing season (April 1-June 10, 2019).
Image has not been reproduced in affiliation with, or with the endorsement of the Government of Canada and was retrieved (14Jun2019).  Access the full map at http://www.agr.gc.ca/DW-GS/current-actuelles.jspx?lang=eng&jsEnabled=true

The growing degree day map (GDD) (Base 10 ºC, April 1-June 10, 2019) is below (Fig. 5):

Figure 5. Growing degree day (Base 10 ºC) across the Canadian prairies for the growing season (April 1-June 10, 2019).
Image has not been reproduced in affiliation with, or with the endorsement of the Government of Canada and was retrieved (14Jun2019).  Access the full map at http://www.agr.gc.ca/DW-GS/current-actuelles.jspx?lang=eng&jsEnabled=true

The lowest temperatures (°C) observed the past seven days are reflected in the map below (Fig. 6).

Figure 6. Lowest temperatures (°C) observed across the Canadian prairies the past seven days (June 7-13, 2019).
Image has not been reproduced in affiliation with, or with the endorsement of the Government of Canada and was retrieved (13Jun2019).  Access the full map at http://www.agr.gc.ca/DW-GS/current-actuelles.jspx?lang=eng&jsEnabled=true

The highest temperatures (°C) observed the past seven days are reflected in the map below (Fig. 7).

Figure 7. Highest temperatures (°C) observed across the Canadian prairies the past seven days (June 7-13 2019).
Image has not been reproduced in affiliation with, or with the endorsement of the Government of Canada and was retrieved (14Jun2019).  Access the full map at http://www.agr.gc.ca/DW-GS/current-actuelles.jspx?lang=eng&jsEnabled=true

B: PRECIPITATION – During the past seven days, rainfall in central regions of AB and southern MB was reported to be greater than 15 mm (Fig. 8). Little or no rain was reported across central areas of SK. Rainfall totals for May 12-June 11 indicated that rainfall amounts were greatest in AB and MB (Fig. 9) while conditions continue to be very dry across most of SK (Fig. 10). 

Figure 8.  Cumulative precipitation (mm) across the Canadian prairies over the past SEVEN days (June 5-11, 2019).
Figure 9. Cumulative precipitation (mm) across the Canadian prairies over the past 30 days (May 12-June 11, 2019).

C: SOIL MOISTURE – Soil moisture values are low across most of the prairies (Fig. 10).

Figure 10. Modeled soil moisture (%) across the Canadian prairies (up to June 11, 2019).

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

Cutworms

John Gavloski and prairiepest_admin
Categories
Week 10

Manitoba continues to experience cutworm issues this spring!  Thanks to John Gavloski (Manitoba Agriculture) who was able to provide a quick summary:

There has been a lot of insecticide applications and some reseeding of crops in Manitoba because of cutworms. Damage is to a variety of crops. Redbacked and dingy cutworms have been the two dominant species, although some other species of cutworms are being found. They are starting to turn to pupae, however stages are quite variable in some fields and scouting and insecticide applications continue.

Please refer back to our earlier Cutworm post (Wk05) for help with scouting and identification tips.  Also access the free downloadable Cutworm Field Guide.

Predicted bertha armyworm development

Ross Weiss, David Giffen, Owen Olfert and Meghan Vankosky
Categories
Week 10

Bertha armyworm (Lepidoptera: Mamestra configurata– Based on BAW model runs, this week pupal development is greater than  80% across most of southern and central areas of the prairies (Fig. 1). Within the next five days BAW adults should begin to emerge in these areas.

Figure 1. Predicted bertha armyworm (Mamestra configurata) pupal development across the Canadian prairies as of June 11, 2019.

Please ensure pheromone traps are out in SK and AB fields this week!

Table 1. Predicted emergence date of bertha armyworm moths at select locations across the Canadian prairies in 2019.

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” as an English-enhanced or French-enhanced version.

A special thanks to John Gavloski (Manitoba Agriculture) who helped update the PPMN Bertha armyworm monitoring protocol.  Use the images below (Fig. 2) to help identify moths from the by-catch that will be retained in phermone-baited unitraps.

Figure 2. Stages of bertha armyworm from egg (A), larva (B), pupa (C) to adult (D). 
Photos: J. Williams (Agriculture and Agri-Food Canada)

Also be sure to review the Insect of the Week which features bertha armyworm and its doppelganger, the clover cutworm!

Predicted grasshopper development

Ross Weiss, David Giffen, Owen Olfert and Meghan Vankosky
Categories
Week 10

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). 

This week, the grasshopper hatch is well underway across the prairies with most locations having 30% (12% last week) hatch and some areas are predicted to have hatch rates of 75%. Approximately 21% of the population is in the first instar (Fig. 1), 7% (2,5% last week) is predicted to be in the second instar (Fig. 2), and 1% in the third instar.  Grasshopper developmental rates are greatest across southern and central regions of SK. Over the past 30 days this region has experienced the warmest and driest conditions for the prairies. Recent, warm temperatures in southern MB has advanced grasshopper development. 

A survey of roadsides south of Saskatoon this week indicated that melanopline species were primarily first and second second instars.  

Figure 1.  Predicted percent of grasshopper (Melanoplus sanguinipes) population at first instar stage across the Canadian prairies (as of June 11, 2019). 
Figure 2. Predicted percent of grasshopper (Melanoplus sanguinipes) population at second instar stage across the Canadian prairies (as of June 11, 2019). 

Biological and monitoring information related to grasshoppers in field crops is posted by Manitoba AgricultureSaskatchewan 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.

Alfalfa weevil

Ross Weiss, David Giffen, Owen Olfert and Meghan Vankosky
Categories
Week 10

Alfalfa Weevil (Hypera postica) – Degree-day maps of base 9°C are produced using the Harcourt/North Dakota models (Soroka et al. 2015).  Models predicting the development of Alfalfa weevil (AAW) across the prairies are updated weekly to help growers time their in-field scouting for second-instar larvae. 

This past week warmer temperatures in southern MB advanced alfalfa weevil development. Weevils are predicted to be primarily in the second (53%) and third instars (22%) across most of southern areas in MB and SK (Fig. 1).

Figure 1. Predicted average instar stage of alfalfa weevil (Hypera postica)  acrossthe Canadian prairies as of June 11, 2019.

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).  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.

Cabbage seedpod weevil

Jennifer Otani
Categories
Week 10

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.  Monitoring should typically begin for this pest as canola enters the bud stage.

Monitoring – Refer to the 2019 update of the PPMN Cabbage seedpod weevil monitoring protocol for detailed information, photos of all insect stages and canola damage:

  • Sample from the bud to flower stages in canola.  
  • 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.  

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.

Provincial Insect Pest Reports

James Tansey, John Gavloski and Scott Meers
Categories
Week 10

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

Manitoba‘s Insect and Disease Updates for 2019 are posted here and includes an update posted June 5, 2019.

Saskatchewan‘s Crops Blog Posts includes a segment on “Early season scouting of cutworms” by Sara Doerksen posted in April 2019 and “Economic thresholds” by Kaeley Kindrachuk posted in May 2019.

•  Alberta Agriculture and Forestry’s Call of the Land regularly includes insect pest updates from Mr. Scott Meers. The most recent Call of the Land was posted March 18-22, 2019 but did not include an insect update.

Crop report links

Jennifer Otani
Categories
Week 10

Crop reports are produced by:

The following crop reports are also available:

Field Events – Speak to an entomologist

Jennifer Otani
Categories
Week 10

Public summer field events – Coming to a field near you –  Prairie field crop entomologists are already scheduled to be at these 2019 field tour events from May-August (be sure to re-confirm dates and details as events are finalized):

•  June 20, 2019: Solstice Forage and Crops Field Tour to be held at the Beaverlodge Research Farm (Beaverlodge AB).  View event info/registration details.  Entomologists tentatively participating: Jennifer Otani, Keith Uloth

•  June 26, 2019: 2019 CanolaPALOOZA to be held at the Lacombe Research and Development Centre (Lacombe AB).  View event info/registration details.  Entomologists tentatively participating: Jennifer Otani, Amanda Jorgensen, Meghan Vankosky, Scott Meers, Shelley Barkley, Patty Reid, Sunil Shivananjappa, Hector Carcamo, Julie Soroka, Mark Cutts, Jim Tansey, Sherrie Benson and the Junior Entomologists.

•  July 9-12, July 16-18, 2019: Crop Diagnostic School. Held at the University of Manitoba Research Farm at Carman, Manitoba. An 2-week diagnostic school will complete units on entomology, plant pathology, weed science, soil fertility, pulse crop production, and oilseed production. View registration and event information. Entomologists participating: John Gavloski and Jordan Bannerman.

•  July 9, 2019: CanolaPALOOZA Saskatoon, to be held at the SRDC Llewellyn Farm. Read more about this event.  Entomologists presenting: Tyler Wist, James Tansey, Greg Sekulic, Meghan Vankosky

•  July 22, 2019: Pulse grower gathering held near Three Hills AB.  Check Alberta Pulse Growers Event Page for more information.  Entomologists presenting: Graduate students from Dr. Maya Evenden’s (U of A) working on pea leaf weevil.

•  July 23-24, 2019: Crop Diagnostic School, Scott Saskatchewan. Read more about this event.  Entomologists presenting: Meghan Vankosky, Tyler Wist.

•  July 24, 2019: Crops-a-Palooza. Held at Canada-Manitoba Crop Diversification Centre (CMCDC), Carberry, Manitoba. Read more about this event. Entomologist participating: John Gavloski, Vincent Hervet, Tharshi Nagalingam, Bryan Cassone.

•  August 8, 2019:  2019 Wheatstalk to be held at Teepee Creek AB.  View event info/registration details.   Entomologists tentatively participating: Jennifer Otani, Amanda Jorgensen, Boyd Mori.

  August 8, 2019. Horticulture School. Agriculture and Agri-Food Canada Research Farm, Portage la Prairie, Manitoba. View event info/registration details.  Entomologist presenting: John Gavloski, Kyle Bobiwash.

Monarch migration

Jennifer Otani
Categories
Week 10

We continue to track the migration of the Monarch butterflies as they move north by checking the 2019 Monarch Migration Map!  A screen shot of the map has been placed below as an example (retrieved 14Jun2019) but follow the hyperlink to check the interactive map.  They are moving further north and west in Manitoba!

Visit the Journey North website to learn more about migration events in North America and visit their monarch butterfly website for more information related to this amazing insect.  

Previous Posts

Jennifer Otani
Categories
Week 10

Click to review these earlier 2019 Posts: 

  ● 2019 Risk and forecast maps – Week 2

 ● Cereal Aphid Manager APP – Week 9
   ● Cereal leaf beetle – Week 9
   ● Crop protection guides – Week 6
   ● Cutworms – Week 5

  ● Field heroes – Week 6
   ● Flea beetles – Week 5

  ● Insect scouting chart for Canola – Week 5
   ● Insect scouting chart for Flax – Week 5

  ● Pea leaf weevil – Week 9
   ● Painted lady butterfly – Week 8

  ● Ticks and Lyme disease – Week 4

  ● Weather Radar – Week 6
   ● Wildfires – Week 8
   ● Wind trajectories – Weeks 1-4

Insect of the Week – Doppelgangers: Bertha armyworm and clover cutworm

Jennifer Otani
Categories
Week 10

The case of the bertha armyworm and the clover cutworm (and other cutworm species)

Clover cutworm larva
cc-by 3.0 Lo Troisfontaine
Bertha armyworm – caterpillar 
Mike Dolinski, MikeDolinski@hotmail.com

Are those bertha armyworms (Mamestra configurata) eating your canola, mustard or alfalfa (also found on lamb’s-quarters, peas, flax, potato)? Or is it maybe a clover cutworm (Discestra trifolii)? [Note: not all cutworm species spend their larval stage underground.] The larvae of the two species are doppelgangers as they are similar in appearance, have a large overlap in host crops, and have similar timing (June-September). Telling them apart can be a challenge but here are few tips to focus on to help distinguish:

Colour:

  • there are generally fewer velvety black clover cutworm caterpillars, with most of the clover cutworm larvae being green or pale brown

Lateral stripe:

  • On the clover cutworm it is yellowish-pink
  • On the bertha armyworm it is yellowish-orange
Climbing cutworm larva – from Cutworm Field Guide
Climbing cutworm adults – from Cutworm Field Guide

In terms of scouting, economic thresholds and control options, treat both species as you would bertha armyworms.

Bertha armyworm – adult
Alberta Agriculture and Rural Development
Clover cutworm adult
cc-by-nc-sa 2.0 Ilona Loser

To learn more about bertha armyworms and clover cutworms, go to the Insect of the Week page or download copies of the Field Crop and Forage Pests andtheir Natural Enemies in Western Canada and Cutworm Pests of Crops onthe Canadian Prairies identification field guides.

Wind Trajectories

Ross Weiss, Serge Trudel, David Giffen and Meghan Vankosky
Categories
Week 10

Agriculture and Agri-Food Canada (AAFC) and Environment and Climate Change Canada (ECCC) have been working together to study the potential of trajectories for monitoring insect movements since the late 1990s.

In a continuing effort to produce timely information, the wind trajectory reports are available in two forms:

Prairie Crop Disease Monitoring Network

Kelly Turkington and prairiepest_admin
Categories
Week 10

The Prairie Crop Disease Monitoring Network (PCDMN) represents the combined effort of our prairie pathologists who work together to support in-field disease management in field crops.  

In 2019, the PCDMN will release a series of weekly Cereal Rust Risk Reports throughout May and June.  Information related to trajectory events based on forecast and diagnostic wind fields and cereal rust risk is experimental, and is OFFERED TO THE PUBLIC FOR INFORMATIONAL PURPOSES ONLY. 

Background:  Agriculture and AgriFood Canada (AAFC) and Environment and Climate Change Canada (ECCC) have been working together to study the potential of trajectories for monitoring insect movements since the late 1990s. Trajectory models are used to deliver an early-warning system for the origin and destination of migratory invasive species, such as diamondback moth. In addition, plant pathologists have shown that trajectories can assist with the prediction of plant disease infestations and are also beginning to utilize these same data. An introduction will be presented of efforts to identify wind trajectory events that may bring rust urediniospores into Western Canada from epidemic areas in the central and Pacific northwest (PNW) regions of the USA. Identification of potential events as well as an assessment of epidemic severity from source locations, and prairie weather conditions, will be used to assess the need for prompt targeted crop scouting for at-risk regions of the Canadian Prairies.

This week, two documents are available from the PCDMN:

Summary of wind trajectory and cereal rust risk assessment and the need for in-crop scouting in the Prairie region, June 4-10, 2019:

1. Pacific Northwest – Currently there is limited stripe rust development in the PNW, a moderate-high number of recent wind trajectories from the PNW, relatively dry Prairie weather conditions, and generally early stages of Prairie crop development, especially in spring cereals.  Thus, as of June 10, 2019, the risk of stripe rust appearance from the PNW is relatively low and scouting for this disease is not urgent.  

2. Texas-Oklahoma corridor –In general, crops are advancing towards maturity, while in many areas of Texas harvesting has been completed, and thus will become less of a source of rust inoculum.  There has been a limited number of recent wind trajectories from this area, relatively dry Prairie weather conditions, and generally early stages of Prairie spring crop development.  Thus, as of June 10, 2019, the risk of leaf and stripe rust appearance from the Texas-Oklahoma corridor is low and scouting for these diseases is not urgent.  

3. Kansas-Nebraska corridor –Leaf and stripe rust development in winter wheat continues in Kansas, although the winter crop is starting to turn colour in some regions.  Although rusts have only been recently reported in Nebraska, levels are on the rise, and thus over the next few weeks this region could act as a significant source of rust inoculum for the Prairie region.  From June 4-10, 2019 there has been a low-moderate number of wind trajectories from this area.  In general, weather conditions have been relatively dry across the Prairies with generally early stages of Prairie crop development depending on the region.  Thus, as of June 10, 2019, the risk of leaf and stripe rust appearance from the Kansas-Nebraska corridor is relatively low and scouting for these diseases is not urgent; however, further development of rust in these regions, especially Nebraska, may increase the risk.  

4. Where farmers or consultants noticed stripe rust development on winter wheat in the fall of 2018, it is recommended to scout winter wheat fields this spring.  Scouting is especially critical where the variety being grown is susceptible to stripe rust.  Currently, there are no reports of stripe rust in commercial fields of winter or spring wheat across the Prairie region.

5.  Access the full downloadable report.


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