Weekly Update (June 6-7, 2019; Wk 09) Otani, Weiss, Giffen, Trudel, Turkington, Svendsen, Olfert, Vankosky

Hello - again!

We had an email glitch so the Weekly Update was released over June 6-7, 2019.  

Please access the complete Weekly Update either as a series of Posts for Week 09 (June 6, 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.

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Weather synopsis (June 6, 2019; Wk 09)

Weather synopsis – The prairie wide average temperature for May was 2 °C cooler than average (Fig. 1) while rainfall was approximately 50% of average (Fig. 2). The coolest conditions have occurred across southern MB and SK. 

Figure 1. Average temperature (°C) across the Canadian prairies for the month of May (May 1-31, 2019).

Figure 2. Mean temperature differences from Normal across the Canadian prairies from May 1-31, 2019.
Image has not been reproduced in affiliation with, or with the endorsement of the Government of Canada and was retrieved (06Jun2019).  Access the full map at http://www.agr.gc.ca/DW-GS/current-actuelles.jspx?lang=eng&jsEnabled=true

This week (May 29 – June 4, 2019) weather conditions were warm and dry. Across the prairies, temperatures were 3-4 °C warmer than last week and 1-2 °C warmer than average (Fig. 3). The warmest temperatures were observed across a region that extended from Medicine Hat AB to Saskatoon SK and southwestern MB.  

Figure 3. Average temperature (°C) across the Canadian prairies the past seven days (May 29-June 4, 2019).

Average 30-day temperatures were warmest in AB and coolest in eastern SK and MB (Fig. 4). Northern locations within the Peace River region were warmer than average. 

Figure 4. Average temperature (°C) across the Canadian prairies the past 30 days (May 5-June 4, 2019).

Seven day cumulative rainfall indicated that minimal rain was observed across most of the prairies (Fig. 5). Most locations reported less than 5 mm.  Higher rainfall amounts were reported in southwestern AB, southeastern SK and an area near Dauphin MB. 

Figure 5. Cumulative precipitation observed the past seven days across the Canadian prairies (May 29-June 4, 2019).

Across the prairies, rainfall amounts for the past 30 days (May 5 – June 4, 2019) were approximately 48 % of normal (Fig. 7 and 8). Most of the prairies reported rainfall amounts less than 40 % of normal. 

Figure 6. Cumulative precipitation observed the past 30 days across the Canadian prairies (May 5-June 4, 2019).

Growing season rainfall (April 1 – June 4) amounts have been well below average for most of the prairies, particularly in west central SK and eastern regions of AB (Fig. 7). Almost all of the prairies has had growing season rainfall that is 85 percent, or less, than average. 

Figure 7. Cumulative precipitation observed for the growing season across the Canadian prairies (April 1-June 4, 2019).

Figure 8. Percent of Average precipitation across the Canadian prairies for the growing season (April 1-June 5, 2019).
Image has not been reproduced in affiliation with, or with the endorsement of the Government of Canada and was retrieved (06Jun2019).  Access the full map at http://www.agr.gc.ca/DW-GS/current-actuelles.jspx?lang=eng&jsEnabled=true

Soil moisture values are low across most of the prairies (Fig. 9). 

Figure 9. Modeled soil moisture (%) across the Canadian prairies (up to June 4, 2019).

The growing degree day map (GDD) (Base 5 ºC, April 1-June 3, 2019) is below (Fig. 10):

Figure 10. Growing degree day (Base 5 ºC) across the Canadian prairies for the growing season (April 1-June 3, 2019).
Image has not been reproduced in affiliation with, or with the endorsement of the Government of Canada and was retrieved (06Jun2019).  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 3, 2019) is below (Fig. 11):

Figure 11. Growing degree day (Base 10 ºC) across the Canadian prairies for the growing season (April 1-June 3, 2019).
Image has not been reproduced in affiliation with, or with the endorsement of the Government of Canada and was retrieved (06Jun2019).  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 ranged from 6 to at least -5 °C in the map below (Fig. 12).

Figure 12. Lowest temperatures (°C) observed across the Canadian prairies the past seven days (May 30-June 5, 2019).Image has not been reproduced in affiliation with, or with the endorsement of the Government of Canada and was retrieved (06Jun2019).  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 ranged from 14 to at least 32 °C in the map below (Fig. 14).

Figure 14. Highest temperatures (°C) observed across the Canadian prairies the past seven days (May 30-June 5, 2019).Image has not been reproduced in affiliation with, or with the endorsement of the Government of Canada and was retrieved (06Jun2019).  Access the full map at http://www.agr.gc.ca/DW-GS/current-actuelles.jspx?lang=eng&jsEnabled=true

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

Predicted bertha armyworm development (June 6, 2019; Wk 09)

Bertha armyworm (Lepidoptera: Mamestra configurata) - Based on BAW model runs, pupal development is nearing 80% in some areas of southern and central AB and SK (Fig. 1). BAW adults may begin to emerge within the next 10 days (Table 1). It is advisable to place pheromone traps in fields when pupal development is 80% to capture the full extent of adult flight activity. Based on this value, traps should be put out in SK and AB fields this week.

Figure 1. Predicted bertha armyworm (Mamestra configurata) pupal development acrossthe Canadian prairies as of June 3, 2019. 

Table 1. Predicted emergence date of bertha armyworm moths at 

select locations across the Canadian prairies in 2019.

Recent warm conditions have advanced bertha armyworm (BAW) pupal development. Compared to last week, development is 2-6 days faster and development is 2 days ahead of normal (based on climate normals).  Model outputs were run for bertha armyworm for Saskatoon SK (Fig. 2), Lethbridge AB (Fig. 3), and Edmonton AB (Fig. 4).

Figure 2. Predicted development of bertha armyworm populations near Saskatoon SK as of June 3, 2019. 

Figure 3. Predicted development of bertha armyworm populations near Lethbridge AB as of June 3, 2019. 

Figure 4. Predicted development of bertha armyworm populations near Edmonton AB as of June 3, 2019. 

Biological and monitoring information related to bertha armyworm in field crops is posted by the provinces of Manitoba, Saskatchewan, Alberta 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.

Cereal leaf beetle (June 6, 2019; Wk 09)

Cereal leaf beetle (Oulema melanopus) - The cereal leaf beetle model indicates hatch has begun (Fig. 1).  Models were projected to June 21, 2019 and run for Lethbridge AB (Fig. 2), Grande Prairie AB (Fig. 3), and Brandon MB (Fig. 4). 

Figure 1.  Percent of populations of cereal leaf beetle (Oulema melanopus) in the larval stage as
of June 3, 2019, across the Canadian prairies. 

Figure 2. Predicted status of cereal leaf beetle populations near Lethbridge AB projected to June 21, 2019, generated using long term average temperatures.

Figure 3. Predicted status of cereal leaf beetle populations near Grande Prairie AB projected to June 21, 2019, generated using long term average temperatures.

Figure 4. Predicted status of cereal leaf beetle populations near Brandon MB projected to June 21, 2019, generated using long term average temperatures.

Lifecycle and Damage:

Adult: Adult cereal leaf beetles (CLB) have shiny bluish-black wing-covers (Fig. 5). 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 5. 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. 6).  When the larva completes its growth, it drops to the ground and pupates in the soil. 

Figure 6.  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 new "Field crop and forage pests and their natural enemies in western Canada - Identification and management field guide".

Predicted grasshopper development (June 6, 2019; Wk 09)

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 (Fig. 1 and 2) with most locations having approximately 15% hatch and some areas having 35% hatch. 

Figure 1. Predicted percent of grasshopper (Melanoplus sanguinipes) population at first instar stage across
the Canadian prairies (as of June 4, 2019). 

Figure 2. Predicted percent of grasshopper (Melanoplus sanguinipes) population at second instar stage across
the Canadian prairies (as of June 4, 2019). 

Model runs for Saskatoon SK (Fig. 3), Lethbridge AB (Fig. 4), and Grande Prairie AB (Fig. 5) were projected to June 30, 2019. Results for Lethbridge and Saskatoon indicated that populations are primarily in the first and second instars. A survey of roadsides south of Saskatoon indicated that melanoplines were primarily first an second instars. 

Figure 3. Predicted status of Melanoplus sanguinipes populations near Lethbridge  AB projected to June 30, 2019.  

Figure 4.  Predicted status of Melanoplus sanguinipes populations near Saskatoon SK projected to June 30, 2019.  

Figure 5.  Predicted status of Melanoplus sanguinipes populations near Grande Prairie AB projected to June 30, 2019.  

Biological and monitoring information related to grasshoppers in field crops is posted by Manitoba Agriculture, Saskatchewan Agriculture, Alberta 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 (June 6, 2019; Wk 09)

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. 

Weather conditions continue to be favourable for development of alfalfa weevil, if alfalfa weevil are present in your area. First instar development is nearing completion (Fig. 1) and the more individuals in the population should be in the second instar stage (Fig. 2). 

Figure 1. Percent of populations of alfalfa weevil (Hypera postica)  in the first instar stage across
the Canadian prairies as of June 3, 2019. 

Figure 2. Percent of populations of alfalfa weevil (Hypera postica)  in the second instar stage across
the Canadian prairies as of June 3, 2019.

Model runs for Brooks AB (Fig. 3)  and Swift Current SK (Fig. 4) were projected to June 21, 2019.  In alfalfa fields near Brooks AB larvae should start to reach the third instar stage late this week. At Swift Current SK third instar larvae will begin to appear approximately 5-7 days later.

Figure 3. Predicted status of alfalfa weevil populations near Brooks AB projected to June 21, 2019, using
long term average temperatures.

Figure 4. Predicted status of alfalfa weevil populations near Swift Current SK projected to June 21, 2019, using
long term average temperatures.

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.

Pea leaf weevil (June 6, 2019; Wk 09)

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.

Prairie Crop Disease Monitoring Network (June 3, 2019; Wk 09) - Turkington

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:
•  An introduction to cereal rust risk and wind trajectories from the USA.
• WIND TRAJECTORY AND CEREAL RUST RISK REPORT for June 3, 2019

Summary of wind trajectory and cereal rust risk assessment and the need for in-crop scouting in the Prairie region, May 28 – June 3, 2019:

1. Pacific Northwest – Currently there is limited stripe rust development in the PNW, a low-moderate number of recent wind trajectories from the PNW, cool and relatively dry Prairie weather conditions, and generally early stages of Prairie crop development, especially in spring cereals.  Thus, as of June 3, 2019, the risk of stripe rust appearance from the PNW is limited and scouting for this disease is not urgent.  

2. Texas-Oklahoma corridor – In general, crops are advancing towards maturity and thus will become less of a source of rust inoculum.  There have been no recent wind trajectories from this area, cool and relatively dry Prairie weather conditions, and generally early stages of Prairie spring crop development.  Thus, as of June 3, 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 – Although leaf and stripe rust development continues in Kansas with a recent report of stripe rust in Nebraska, it is at low-moderate levels, although there have been reports of elevated levels in regions of Kansas.  There have been no recent wind trajectories from this area, cool and relatively dry Prairie weather conditions, and generally early stages of Prairie crop development.  Thus, as of June 3, 2019, the risk of leaf and stripe rust appearance from the Kansas-Nebraska corridor is low and scouting for these diseases is not urgent, but further development of rust in these regions 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 that have resumed growth this spring.  Scouting is especially critical where the variety being grown is susceptible to stripe rust.  Currently, there are no early spring reports of stripe rust on commercial fields of winter wheat in the prairie region.

5.  Access the full downloadable report.

Cereal Aphid Manager (CAM) (June 6, 2019; Wk09)

Congratulations!  The Cereal Aphid Management (CAM) Mobile Application Team was recognized with an Agriculture and Agri-Food Canada Gold Harvest Award this month!  Team members included Ashraf Eid, Paul Faure, John Gavloski, François Jodoin, Elham Karimi, Eric Li, Jackson Macdonald, Nancy MacDonald, Owen Olfert, Chrystel Y. Olivier, 

Daniel Shen, Erl Svendsen, Gabriel Tobian, Tyler J. Wist.

"The app is a culmination of innovative thinking, extensive research, and most importantly collaboration in order to design a tool that met the needs of the farming community. The team’s ability to work together and build this application will result in economic savings, a greener environment, and increased crop quality in the food production industry."

The Cereal Aphid Manager is an easy-to-use mobile app that helps farmers and crop advisors control aphid populations in wheat, barley, oat or rye. It is based on Dr. Tyler Wist's (AAFC-Saskatoon) innovative Dynamic Action Threshold model. The model treats the grain field as an ecosystem and takes into account many complex biological interactions including:

• the number of aphids observed and how quickly they reproduce
• the number of different natural enemies of aphids in the field and how many aphids they eat or parasitize per day
• the lifecycles of aphids and their enemies taking into account developmental stages, egg laying behaviour, population growth rate, lifespan, etc.

By taking into consideration factors like these, the app predicts what the aphid population will be in seven days and the best time to apply insecticide based on economic thresholds.

Available in iOS and Android.

To learn more and to download, go to AAFC's CAM webpage.

Note: Cereal aphids can blow up from the South at any time which cannot be predicted by the app. Therefore, farmers and crop advisors should regularly check fields during the growing season regardless of what Cereal Aphid Manager Mobile may recommend.

CAM Homepage

CAM monitoring report and recommendation

CAM icon

Field Events - Speak to an entomologist (June 6, 2019; Wk 09)

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. Entomologist presenting: John Gavloski, Kyle Bobiwash.

Provincial Insect Pest Reports (June 6, 2019; Wk 09)

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.