ALERT – Wind Trajectory Report for May 7

Environment and Climate Change Canada (ECCC) trajectory models indicate that air trajectories, originating over the Pacific Northwest (Idaho, Oregon, Washington), have crossed a number of Alberta locations including Lethbridge, Beiseker, Olds, Manning, Rycroft, and Wanham.

Access this special one-page alert to learn more. Albertans please take note!

Action: Areas highlighted green in this alert may receive incoming winds from the Pacific Northwest of the USA very shortly so please deploy diamondback pheromone traps as soon as possible!

Weekly Update

Seeders are rolling across the prairies this week and we’re back for 2021 with Week 1! In addition to the Weekly Update, be sure to catch the Insect of the Week and Wind Trajectory Report.

Now, more than ever, we wish everyone a safe and productive field season! Stay Safe!

Questions or problems accessing the contents of this Weekly Update?  Please contact us so we can connect you to our information. Past “Weekly Updates” can be accessed on our Weekly Update page.

Weather synopsis

Since April 1, the 2021 growing season has been cooler and dryer than normal. This past week (April 26-May 2, 2021), the average temperature across the prairies was approximately 0.5 °C cooler than normal. Similarly, the average 30-day temperature (April 3- May 2) was 0.6 °C less than climate normal values. Temperatures have been warmest in southern Alberta. Seven day cumulative rainfall indicates that below normal rain (79% of average) was reported for the prairies.

Figure 1. 7-day average temperature (°C) across the Canadian prairies for the period of April 26-May 2, 2021.
Figure 2. 30-day average temperature (°C) across the Canadian prairies for the period of April 3-May 2, 2021.

The growing degree day map (GDD) (Base 5 ºC, April 1-May 2, 2021) is below (Fig. 3) while the growing degree day map (GDD) (Base 10 ºC, April 1-August 9, 2020) is shown in Figure 4.

Figure 3. Growing degree day map (Base 5 °C) observed across the Canadian prairies for the growing season (April 1-May 3, 2021).
Image has not been reproduced in affiliation with, or with the endorsement of the Government of Canada and was retrieved (06May2021). Access the full map at https://www.agr.gc.ca/DW-GS/current-actuelles.jspx?lang=eng&jsEnabled=true
Figure 4. Growing degree day map (Base 10 °C) observed across the Canadian prairies for the growing season (April 1-May 3, 2021).
Image has not been reproduced in affiliation with, or with the endorsement of the Government of Canada and was retrieved (06May2021). Access the full map at https://www.agr.gc.ca/DW-GS/current-actuelles.jspx?lang=eng&jsEnabled=true

At this early point in the growing season, cool temperatures pose the risk of frost but the differences between low and high temperatures can exert incredible stress on newly germinating plants in field crops. The lowest temperatures ranged from <-14 to >0 °C (Fig. 5) while the highest temperatures (°C) observed across the Canadian prairies the past seven days ranged from <3 to >24 °C (Fig. 6).

Figure 5. Lowest temperatures (°C) observed across the Canadian prairies the past seven days (April 29-May 5, 2021).
Image has not been reproduced in affiliation with, or with the endorsement of the Government of Canada and was retrieved (06May2021). Access the full map at https://www.agr.gc.ca/DW-GS/current-actuelles.jspx?lang=eng&jsEnabled=true
Figure 6. Highest temperatures (°C) observed across the Canadian prairies the past seven days (April 29-May 5, 2021).
Image has not been reproduced in affiliation with, or with the endorsement of the Government of Canada and was retrieved (06May2021). Access the full map at https://www.agr.gc.ca/DW-GS/current-actuelles.jspx?lang=eng&jsEnabled=true

Rain (30-day accumulation) amounts have been less than average for most of the prairies (75 % of average; Fig. 7). Rainfall for April 3-May 2, 2021, has been greatest for southeastern Manitoba and the extreme southwest of Alberta (Fig. 8).

Figure 7. 30-day cumulative rainfall (mm) observed across the Canadian prairies the past 30 days (April 1-May 2, 2021).
Figure 8. Seven-day cumulative rainfall (mm) observed across the Canadian prairies the past 30 days (April 26-May 2, 2021).

The maps above are all produced by Agriculture and Agri-Food Canada. Growers can bookmark the AAFC Current Conditions Maps for the growing season. Historical weather data can be access at the AAFC Drought Watch Historical website, Environment Canada’s Historical Data website, or your provincial weather network.

Access the PPMN’s Weekly Wind Trajectory report released May 5, 2021.

FYI: Environment and Climate Change Canada updated the weather radar mapping interface recently.

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).  

Model simulations were used to estimate percent grasshopper embryonic development as of May 2, 2021. Results indicate that egg development has begun across the southern prairies (Fig. 1) and progression estimates for sites across the prairies are presented in Figure 2.

Figure 1. Predicted grasshopper (Melanoplus sanguinipes) embryological development across the Canadian prairies as of May 2, 2021. 
Figure 2. Predicted percent embryonic development of overwintered grasshopper eggs across the Canadian prairies as of May 2, 2021. 

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

Cereal leaf beetle development

The cereal leaf beetle (CLB) model output suggests that overwintered adults are active and that oviposition is underway across the prairies. The graphs provide a comparison of development for Lethbridge (Fig. 1) and Saskatoon (Fig. 2).

Figure 1. Predicted status of cereal leaf beetle populations near Lethbridge AB as of May 2, 2021.
Figure 2. Predicted status of cereal leaf beetle populations near Saskatoon SK as of May 2, 2021.

Lifecycle and Damage:

Adult: Adult cereal leaf beetles (CLB) have shiny bluish-black wing-covers (Fig. 3). The thorax and legs are light orange-brown. Females (4.9 to 5.5 mm) are slightly larger than 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 temperatures reach 10-15 ºC and the adults are active for about 6 weeks. They usually begin feeding on grasses, then move into winter cereals and later into spring cereals.  

Figure 3. Adult Oulema melanopus measure 4.4-5.5 mm long (Photo: M. Dolinski).

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. 4).  When the larva completes its growth, it drops to the ground and pupates in the soil. 

Figure 4.  Larval stage of Oulema melanopus with characteristic feeding damage visible on leaf (Photo: M. Dolinski).

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 “Field crop and forage pests and their natural enemies in western Canada – Identification and management field guide” (2018; accessible in either English-enhanced or French-enhanced versions).

Alfalfa weevil predicted development

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. 

Model simulations for alfalfa weevil (AAW) indicate that oviposition should have begun across central and western areas of the prairies. The following graphs indicate, based on potential number of eggs, that development is more advanced near Regina SK (Fig. 1) than Winnipeg MB (Fig. 2).

Figure 1. Projected predicted status of alfalfa weevil populations near Regina SK as of May 2, 2021.
Figure 2. Projected predicted status of alfalfa weevil populations near Winnipeg MB as of May 2, 2021.

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 9 mm long.  

Figure 3. Developmental stages of the alfalfa weevil (Hypera postica). Composite image: J. Soroka (AAFC-Saskatoon).

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” (2018; accessible in either English-enhanced or French-enhanced versions).

Field heroes

The Field Heroes campaign continues to raise awareness of the role of beneficial insects in western Canadian crops. Check the recently updated Field Heroes website for scouting guides, downloadable posters, and videos. Learn about these important organisms at work in your fields!  

Two important NEW resources for 2021 include:

  1. The NEW Pests and Predators Field Guide is filled with helpful images for quick insect indentification and plenty of tips to manage the pests AND natural enemies in your fields. Claim your free copy at http://fieldheroes.ca/fieldguide/ or download for free to arm your in-field scouting efforts!

2. Real Agriculture went live in 2021 with Season 2 of the Pest and Predators podcast series!

• Access Episode 6 – Powerful parasitoids: Better than fiction (April 20, 2021)

• Access Episode 7 – Good vs pea leaf weEVIL (May 4, 2021)

• Recap of SEASON 1: Episode 1 – Do you know your field heroes? Episode 2 – An inside look at the Prairie Pest Monitoring Network. 3 – How much can one wasp save you? Episode 4 – Eat and be eaten — grasshoppers as pests and food Episode 5 – Killer wasp has only one target — wheat stem sawfly Episode 6Plentiful parasitoids

Access ALL the Field Heroes links here and be sure to follow @FieldHeroes!

Provincial insect pest report links

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

Manitoba‘s Crop Pest Updates for 2021 will soon become available. Be sure to bookmark their insect pest homepage to prepare for the season!

Saskatchewan‘s Crop Production News will soon be available. Access the new Crops Blog Posts and review Saskatchewan’s 2020 insect pest surveying results in order to prepare for 2021. Be sure to bookmark their insect pest homepage to access important information! Also, diamondback moth pheromone trap monitoring has begun in the province. To date, no moths have been intercepted (2021May06 Tansey, pers. comm.).

•  Alberta Agriculture and ForestryNEW for 2021 – AAF’s Shelley Barkley has gathered and streamlined information into a Major Crops Insect webpage. The new webpage does not replace the Alberta Insect Pest Monitoring Network page (where insect survey maps, live feed maps, and insect trap set-up videos can be found). However, the new Major Crops Insect webpage serves as a table of contents, connecting users to crop insect pest information on alberta.ca. It offers links to specific insect identification, life cycle, damage, monitoring and management. Users will hopefully find pertinent insect information with fewer clicks! Remember, AAF’s Agri-News occasionally includes insect-related information or Twitter users can connect to #ABBugChat Wednesdays at 10:00 am.

Crop report links


Click the provincial name below to link to online crop reports produced by:

• Manitoba Agriculture and Resource Development – Subscribe to receive, or access a PDF copy of the May 4, 2021 report.

• Saskatchewan Agriculture  or access a PDF copy of the May 3, 2021 report.

• Alberta Agriculture and Forestry or access a PDF copy of the report expected for public release on May 7, 2021.

The following crop reports are also available:

• The United States Department of Agriculture (USDA) produces a Crop Progress Report (read a PDF copy of the May 3, 2021 edition).

• The USDA’s Weekly Weather and Crop Bulletin (read a PDF copy of the May 4, 2021 edition). 

Weekly Wind Trajectory Report (released May 5)

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. Trajectory models are used to deliver an early-warning system for the origin and destination of migratory invasive species, such as diamondback moth.

Access a PDF version of the full report for May 5, 2021.

The cutworms are coming …

For many, seed isn’t in the ground yet, but cutworms may be in the soil ready for when it does. 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. 

While they may be related and share many similarities, cutworms are not all the same, nor cause the same kind of damage. For example, the armyworm (Mythimna unipuncta) is a climbing cutworm and feeds on leaves. In contrast, young pale western cutworms (Agrotis orthogonia) feed on the surface of newly-emerging shoots and furled leaves of young plants causing small holes and older larvae sever plants just below the soil surface and occasionally pull and eat severed plants underground. In addition, there is likely more than one cutworm species present in your field. 

A few of the important cutworms we’ve highlighted in the past include army, darksided, dingy, glassy, pale western and redbacked cutworms. There is a lot more information about cutworm lifecycle, the damage they cause, and management options in the recent Cutworm Pests of Crops on the Canadian Prairies. For even more information on cutworms (and many other pests) including information about their natural enemies, check out Field Crop and Forage Pests and their Natural Enemies in Western Canada.

Pale western cutworm,  Frank Peairs (cc-by-nc 3.0)