Prairie Crop Disease Monitoring Network

The Prairie Crop Disease Monitoring Network (PCDMN) represents the combined effort of  prairie pathologists working together to support in-field disease management in field crops.  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.  Read the OVERVIEW describing the collaborative nature of this effort and the methods employed.  

Wind trajectory and cereal rust risk assessment and need for in-crop scouting in the Prairie region, June 16-22, 2020

1. Pacific Northwest – There moderate number of reverse wind trajectories that passed over the PNW region and into the prairies.  Locations with the highest number of days with events (3-4) with reverse trajectories from the PNW included: Lethbridge (4) and Olds (3), AB; Regina (3), Saskatoon (3) and Yorkton (3), SK; and Brandon (3) and Dauphin (3), MB.  Of note was the occurrence of 1-2 days with trajectory events that ended up in the Fort Vermilion, Grande Prairie, Manning, and Rycroft areas of the Peace Region of Alberta.  Currently there appears to be relatively low levels of stripe rust development in the PNW, although this may change over the week, although later season (anthesis) fungicide applications may limit further stripe rust development in PNW winter wheat crops.  Temperatures have been in the 15-20C range for most of Manitoba, southeastern Saskatchewan, the Lethbridge area, and the Peace Region.  Other Prairie regions had average temperatures from June 15-21, 2020 of 11 to 15C.  This past week, rainfall amounts were greatest across central regions of SK and eastern MB.  In contrast, limited rainfall occurred in the Grande Prairie region and from Manning to High Level/Fort Vermilion, AB, and in large areas of central to western Manitoba. Winter wheat crops are progressing towards head emergence and flowering, while Prairie spring wheat development ranges from the end of the seedling stage to stem elongation.  There have been reports of stripe rust in western Idaho and on June 16, 2020 from southern Alberta, specifically the County of Lethbridge.  On June 19, 2020 there was a third report in Alberta with the observation of stripe rust in winter wheat yield trials at AAFC Beaverlodge. Given the appearance of stripe rust in the Nobleford area of the County of Lethbridge, and at Beaverlodge in the Country of Grande Prairie, farmers in these regions should be on the look out for stripe rust in wheat.  Special focus should be on wheat fields seeded to varieties rated as susceptible or moderately susceptible.  These recent observations in Alberta indicate that Prairie regional sources of inoculum may become more important with further crop and disease development.  Thus, as of June 22, 2020 the risk of stripe rust appearance from the PNW or from regional sources is low to moderate.  However, some locations may be at an increased stripe rust risk, especially where there were 3-4 reverse trajectory events from the PNW or in Prairie regions where stripe rust has been reported.

2. Texas-Oklahoma corridor – Currently, there is very limited leaf and stripe rust development in this corridor.  Moreover, as the Texas and Oklahoma winter wheat crops continue to be harvested, this region no longer represents a significant source of cereal rust inoculum for movement into the Prairie region.  Thus, as of June 22, 2020 the risk of leaf and stripe rust appearance from the Texas-Oklahoma corridor is limited and scouting for these diseases is not urgent.  

3. Kansas to Nebraska corridor – Currently there appears to be relatively low levels of stripe rust development in the Kansas to Nebraska.  Looking at specific locations in Prairie region and reverse trajectories, only 10 of 29 locations had only 1-3 days each with reverse trajectories originating over the states of Kansas and Nebraska from June 16-22, 2020, with the remaining locations having zero.  Locations with the highest number of days with events (3) with reverse trajectories from the PNW included: Brandon (3) and Selkirk (3), MB.  Eight locations in Saskatchewan and Manitoba had 1-2 days with events, while the remaining locations had no events from June 16 to 22, 2020 (Table 2).  Temperatures have been in the 15-20C range for most of Manitoba, southeastern Saskatchewan, the Lethbridge area, and the Peace Region.  Other Prairie regions had average temperatures from June 15-21, 2020 of 11 to 15C.  This past week, rainfall amounts were greatest across central regions of SK and eastern MB.  In contrast, limited rainfall occurred in the Grande Prairie region and from Manning to High Level/Fort Vermilion, AB, and in large areas of central to western Manitoba. Winter wheat crops are progressing towards head emergence and flowering, while Prairie spring wheat development ranges from the end of the seedling stage to stem elongation.  Thus, as of June 22, 2020 the risk of leaf and stripe rust appearance from the Kansas-Nebraska corridor is limited and scouting for these diseases is not urgent.  In Kansas the winter wheat crop is rapidly maturing with harvesting occurring in some areas, and thus no longer represents a significant source of rust inoculum.  The Nebraska winter wheat crop has mostly headed and in some areas is starting to turn with harvest 1-2 weeks away.  With the Nebraska winter wheat crop progressing towards maturity and harvest, and given limited reports of disease, this state is becoming less of a potential source of rust inoculum.  There continue to be reports of low levels of stripe rust in South Dakota and Wisconsin.  Thus, given the proximity to the Prairie region, these reports serve as a warning that farmers and crop scouts in the central to eastern Prairie region of Canada should be on the look out for stripe rust, especially in winter wheat fields.

4. Where farmers or consultants noticed stripe rust development on winter wheat in the fall of 2019, it is recommended to scout winter wheat fields that have resumed growth in spring 2020.  Scouting is especially critical where the variety being grown is susceptible to stripe rust.  Currently, there have been three reports of the initial appearance of stripe rust on winter wheat on June 5, 16, and 19, 2020 in the County of Lethbridge in southern Alberta and in the County of Grande Prairie in the Peace Region of Alberta.  Given the appearance of stripe rust in the Counties of Lethbridge and Grande Prairie, farmers in these regions should be on the look out for stripe rust in wheat.  Special focus should be on wheat fields seeded to varieties rated as susceptible or moderately susceptible.

5. Read the full report here.  

Monarch migration

We again track the migration of the Monarch butterflies as they move north by checking the 2020 Monarch Migration Map!  A screen shot of the map showing reported first sightings of adults is below as reference (retrieved 25Jun2020) but follow the hyperlinks to check the interactive map! 

This week monarchs have moved even further north with more sightings in Manitoba, Saskatchewan, central Alberta and southern British Columbia. 

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 fascinating insect. 

Previous posts

Click to review these earlier 2020 Posts (organized alphabetically):

    • 2019-2020 Risk and forecast maps

    • Alfalfa weevil (Wk08)
    • Aster leafhopper (Wk05)

    • Beetle data please! (Wk03)

    • Crop protection guides (Wk02)
    • Cutworms (Wk02)

    • Flea beetles (Wk02)

    • Prairie provincial insect pest pages (Wk02)

    • Scouting charts - canola and flax (Wk02)

    • Ticks and Lyme Disease (Wk06)

Insect Pest of the Week and the Entomologists that Study Them (June 22): Flax Pests / Feature entomologist: Boyd Mori

This week’s Insect of the Week feature crop is flax, a crop that thrives in cooler environments. Our feature entomologist this week is Boyd Mori.

Flax Seeds cc by 2.0 Tia Mont

Note: 

This year, we're doing things a bit differently for our Insect of the Week. Instead of focussing on a single insect (pest or natural enemy), we're looking at it from a crop perspective. Each week, we'll pick a crop and list the insects that attack it along with additional helpful information. The insect list is based on the information found in the Field Crop and Forage Pests and their Natural Enemies in Western Canada: Identification and Management field guide. The field guide offers information describing lifecycle, damage description, monitoring/scouting strategies, economic thresholds (where available) and control options) for each economic pest.

In addition to an Insect of the Week, we'll also feature one of the entomologists that helps support the PPMN, either directly or indirectly.

Weekly Update (June 18, 2020; Wk 08) Otani, Weiss, Rounce, Trudel, Svendsen, Evenden, Turkington, Olfert, Vankosky

Another BIG Weekly Update - several predictive model updates have been generated this week! Find updated information for bertha armyworm, grasshoppers, cereal leaf beetle, alfalfa weevil, wheat midge and pea leaf weevil.  Keep scrolling down and it's time to get in fields to scout!

Access information to support your in-field insect monitoring efforts in the complete Weekly Update either as a series of Posts for Week 8 OR a downloadable PDF.

Stay Safe!

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

Subscribe to the Blog by following these easy steps!

Weather synopsis

Weather synopsis – This week (June 8-14, 2020), temperatures were generally warmer than average and seven day rainfall totals were above average.  Average 7-day temperatures were warmest across Manitoba, Saskatchewan and eastern Alberta.  Temperatures were cooler across the Parkland and Peace River regions.  The weekly average temperature at Brandon (16.8 °C) was more than 3 °C warmer than at Grande Prairie.  

Table 1. 7-day temperature and rainfall summary (June 8-14, 2020)

Figure 1. Observed average temperatures across the Canadian prairies for the past seven days (June 8-14, 2020).

Average 30-day (May 16 - June 14, 2020) temperatures continue to be cooler in Alberta than in Saskatchewan and Manitoba.  Temperature anomalies indicated that northwestern Saskatchewan and a region extending from Calgary to Grande Prairie has been 0 to 2 °C cooler than normal. Most of Manitoba and Saskatchewan have been 0 to 2 °C warmer than normal (May 19 - Jun 15, 2020).  

Table 2. 30-day temperature and rainfall summary (May 16 -June 14, 2020)

Figure 2. Observed average temperatures across the Canadian prairies for the past seven days (May 16-June 14, 2020).

Figure 3. Mean temperature difference from Normal across the Canadian prairies the past 30 days (May 19-June 15, 2020). Image has not been reproduced in affiliation with, or with the endorsement of the Government of Canada and was retrieved (15Jun2020). Access the full map at http://www.agr.gc.ca/DW-GS/current-actuelles.jspx?lang=eng&jsEnabled=true&reset=1588297059209  

This past week, rainfall amounts were greatest in Alberta and southern/east-central Saskatchewan. Rainfall in Manitoba was minimal.  Seven-day total rainfall for Grande Prairie was 35.4 mm compared to 1.7 mm at Brandon.  Eastern Saskatchewan and Manitoba have had the lowest 30-day cumulative rainfall amounts; precipitation has been greatest in Alberta.  At Saskatoon and Lacombe, rainfall has been greater than 200% of long term (30-day) normal values.  Conditions continue to be dryer than normal across most of Saskatchewan and Manitoba.  Rainfall amounts have been well above normal across most of Alberta as well as northwestern Saskatchewan. 

Figure 4. Observed cumulative precipitation across the Canadian prairies for the past seven days (June 8-14, 2020).

Figure 5. Observed cumulative precipitation across the Canadian prairies for the past 30 days (May 16-June 14, 2020).

Figure 6. Percent of average precipitation the past 30 days (May 16-June 14, 2020). Image has not been reproduced in affiliation with, or with the endorsement of the Government of Canada and was retrieved (15Jun2020). Access the full map at http://www.agr.gc.ca/DW-GS/current-actuelles.jspx?lang=eng&jsEnabled=true&reset=1588297059209

The growing degree day map (GDD) (Base 5 ºC, April 1-June 15, 2020) is below (Fig. 7):

Figure 7. Growing degree day map (Base 5 °C) observed across the Canadian prairies for the growing season (April 1-June 15, 2020). Image has not been reproduced in affiliation with, or with the endorsement of the Government of Canada and was retrieved (15Jun2020). Access the full map at http://www.agr.gc.ca/DW-GS/current-actuelles.jspx?lang=eng&jsEnabled=true&reset=1588297059209

The growing degree day map (GDD) (Base 10 ºC, April 1-June 1, 2020) is below (Fig. 8):

Figure 8. Growing degree day map (Base 10 °C) observed across the Canadian prairies for the growing season (April 1-June 15, 2020). Image has not been reproduced in affiliation with, or with the endorsement of the Government of Canada and was retrieved (15Jun2020). Access the full map at http://www.agr.gc.ca/DW-GS/current-actuelles.jspx?lang=eng&jsEnabled=true&reset=1588297059209

The lowest temperatures (°C) observed the past seven days ranged from <-1 to >8 °C in the map below (Fig. 9).

Figure 9. Lowest temperatures (°C) observed across the Canadian prairies the past seven days (April 1-June 15, 2020). Image has not been reproduced in affiliation with, or with the endorsement of the Government of Canada and was retrieved (15Jun2020). Access the full map at http://www.agr.gc.ca/DW-GS/current-actuelles.jspx?lang=eng&jsEnabled=true&reset=1588297059209

The highest temperatures (°C) observed the past seven days ranged from <15 to >32 °C in the map below (Fig. 10).

Figure 10. Highest temperatures (°C) observed across the Canadian prairies the past seven days (April 1-June 15, 2020). Image has not been reproduced in affiliation with, or with the endorsement of the Government of Canada and was retrieved (15Jun2020). Access the full map at http://www.agr.gc.ca/DW-GS/current-actuelles.jspx?lang=eng&jsEnabled=true&reset=1588297059209

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

Wind Trajectories

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.

The entire list of 2020 Wind Trajectory Reports is available here.
→ Read the WEEKLY Wind Trajectory Report for Wk08 (released June 15, 2020).

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 14, 2020, the simulation estimates that hatch varies between 14.5% at Grande Prairie and Lacombe to more than 85% at Winnipeg and Regina (Table 1; Fig. 1).  The prairie average, is 34% (20% last week) and well above the long term average of 10% (4.5% last week) for this point in the growing season (Fig. 1).  Across the prairies, populations are predicted to be 65, 18, 11 and 4% in egg, first, second, and third instars, respectively (Table 1).  

Table 1.  Predictive model output estimates for Melanoplus sanguinipes development (% of total population for each location) at selected sites across the Canadian prairie as of June 14, 2020.

Figure 1. Grasshopper hatch (%) based on model simulations using current environmental conditions (blue bars) compared to long-term normal (red bars) as of June 14, 2020.
*LTN = long term climate normals, used for comparison of current year development (OBS)

Grasshopper hatch is greatest in across the southern prairies; areas bound within the black line in the map below are those where 50% or more of eggs have hatched, according to the simulation model (Fig. 2).  

Figure 2. Predicted percent of grasshopper (Melanoplus sanguinipes) population at hatching stage across
the Canadian prairies (as of June 14, 2020). 

First instar grasshoppers are predicted to be present across the prairies, with first occurrence of hatchlings near Edmonton and southern Peace River region in the past week (Fig. 3).  Warmer conditions across southern regions of the prairies should result in appearance of third instar nymphs (Fig. 4).  

Figure 3. Predicted percent of grasshopper (Melanoplus sanguinipes) population at first instar stage across
the Canadian prairies (as of June 14, 2020). 

Figure 4. Predicted percent of grasshopper (Melanoplus sanguinipes) population at third instar stage across
the Canadian prairies (as of June 14, 2020). 

The two graphs compare development for Regina and Saskatoon.  The graphs illustrate that grasshopper populations near Saskatoon are predominantly in the first instar with relatively few grasshoppers in the second and third instars (Fig. 5).  Populations near Regina may be expected to have grasshoppers nymphs in first to fourth instar stages of development (Fig. 6).

Figure 5. Predicted grasshopper (Melanuplus sanguinipes) phenology at Saskatoon SK.
Values are based on model simulations (April 1-June 14, 2020).

Figure 6. Predicted grasshopper (Melanuplus sanguinipes) phenology at Regina SK.
Values are based on model simulations (April 1-June 14, 2020).

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 "Field Crop and Forage Pests and their Natural Enemies in Western Canada: Identification and management field guide" (Philip et al. 2018) as an English-enhanced or French-enhanced version.

Bertha armyworm monitoring

Bertha armyworm (Lepidoptera: Mamestra configurata) - Model simulations to June 14, 2020, indicate that pupal development is greater than 90% across most of Saskatchewan and Manitoba.  Pupal development is predicted to be slower across central and northern regions of Alberta.  First occurrence of BAW should be occurring in isolated regions across southern Alberta, Saskatchewan and Manitoba. In fact, adult BAW were reported in Saskatoon by Dr. Julie Soroka on June 17, 2020.  By next week adults should be emerging across most of the prairies.  

Figure 1. Predicted bertha armyworm (Mamestra configurata) pupal development across
the Canadian prairies as of June 14, 2020. 

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 "Field Crop and Forage Pests and their Natural Enemies in Western Canada: Identification and management field guide" which is a free downloadable document as both an English-enhanced or French-enhanced version.

Refer to the PPMN Bertha armyworm monitoring protocol for help when performing in-field scouting.  Use the images below (Fig. 2) to help identify egg masses and the economically important larvae in canola.  Review the 2019 Insect of the Week which featured bertha armyworm and its doppelganger, the clover cutworm!

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

Cereal leaf beetle

Cereal leaf beetle (Oulema melanopus) - As of June 14, 2020, cereal leaf beetle (CLB) simulations indicate that oviposition is almost complete with 30% of the population in the egg stage (Table 1).  

Table 1. Predictive model output estimates for O. melanopus development (% of total population for each location) at selected sites across the Canadian prairies (as of June 14, 2020).

Across the prairies, first instar larvae are predicted to be most abundant (prairie average; Fig. 1).  This week, fourth instar larvae may begin to occur.  The following three maps illustrate larval development of first (Fig. 1), second (Fig. 2) and third instar (Fig. 3) stages across the prairies. Based on the simulation, development is greatest across southern Manitoba and southern Saskatchewan.

Figure 2. Predicted percent of cereal leaf beetle (Oulema melanopus) population at first instar stage across the Canadian prairies (as of June 14, 2020).  

Figure 3. Predicted percent of cereal leaf beetle (Oulema melanopus) population at second instar stage across the Canadian prairies (as of June 14, 2020).  

Figure 4. Predicted percent of cereal leaf beetle (Oulema melanopus) population at third instar stage across the Canadian prairies (as of June 14, 2020).  

Manitobans - Dr. John Gavloski is looking for samples of cereal leaf beetle larvae this growing season to determine their range across Manitoba, their population density, and the rate at which larvae are parasitized. Please contact John.Gavloski@gov.mb.ca or @JohnTheBugGuy if you observe cereal leaf beetles in your fields. 

Canadians - Dr. Haley Catton is looking for samples of cereal leaf beetle larvae this growing season too!  Help her monitor for the tiny beneficial wasp, Tetrastichus julis, that lives inside the larvae of cereal leaf beetle.  Tracking these biological control agents will help Dr. Catton learn more about their distribution and value in fields.  Please check her Twitter poster for more details or contact her at @HaleyCatton or Haley.Catton@canada.ca . Access the recently released Pests & Predators podcast by Real Agriculture which features Dr. Haley Catton and this powerful parasitoid!

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 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 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" available as a free downloadable document in either an English-enhanced or French-enhanced version.

Alfalfa weevil

Alfalfa Weevil (Hypera postica) – Model output indicates that hatch is almost complete with less than 5% of the population predicted to still be in the egg stage (prairie average; Table 1). Across the prairies, populations are predicted to be 12, 45, 29 and 10% in first, second, third and fourth instars, respectively.  

Table 1.  Predictive model output estimates for Hypera postica development (% of total population for each location) at selected sites across the Canadian prairie as of June 14, 2020.

Larval populations in the Peace River region are expected to be mostly in the second instar (Fig. 1).  Last week, the presence of third instar larvae was limited to areas southeast of Saskatchewan and extended into Manitoba (Fig. 2).  This week third instar larvae should be occurring across southern and central regions of the prairies (Fig. 3).  Fourth instar larvae should be abundant across southern Manitoba and southeastern Saskatchewan.

Figure 1. Predicted percent of populations of alfalfa weevil (Hypera postica) in the second instar stage across

the Canadian prairies as of June 14, 2020. 

Figure 2. Predicted percent of populations of alfalfa weevil (Hypera postica) in the third instar stage across

the Canadian prairies as of June 14, 2020. 

Figure 3. Predicted percent of populations of alfalfa weevil (Hypera postica) in the fourth instar stage across

the Canadian prairies as of June 14, 2020. 

Monitoring

The larval stage of this weevil feeds on alfalfa leaves in a manner that characterizes the pest as a “skeletonizer” (Fig. 3, lower left).  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 (Fig. 3, upper right).  

Figure 3.  Developmental stages of the alfalfa weevil (Hypera postica); overwintered adult (upper row L-R), eggs, larvae, larva feeding or "skeletonizing" alfalfa leaf (lower row L-R), pupa within lacey cocoon, pupa, and newly emerged adult.

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. 2018). The guide is available as an English-enhanced or French-enhanced version.

Predicted pea leaf weevil development

Pea Leaf Weevil (Sitona lineatus) –  As of June 14, 2020, PLW model runs indicate that PLW females continue to oviposit eggs.  The following two graphs illustrate that egg numbers continue to increase at Swift Current (Fig. 1) and Lacombe (Fig. 2).  This week, first appearance of PLW larvae is expected to occur at Swift Current (Fig. 1). 

Figure 1. Predicted pea leaf weevil (Sitona lineatus) phenology at Swift Current SK.
Values are based on model simulations (April 1-June 14 2020).

Figure 2. Predicted pea leaf weevil (Sitona lineatus) phenology at Lacombe AB.
Values are based on model simulations (April 1-June 14 2020).

Link here to access photos of PLW and related species of weevils which can all be active simultaneously in Canadian prairie field crops. 

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. 

Predicted wheat midge development

Wheat Midge (Sitodiplosis mosellana) – Wheat midge overwinter as larval cocoons in the soil.  Soil moisture conditions in May and June can have significant impact on wheat midge emergence.  Adequate rainfall promotes termination of diapause and movement of larval to the sol surface where pupation occurs.  Insufficient rainfall in May and June can result in delayed movement of larvae to the soil surface. Elliott et al. (2009) reported that wheat midge emergence was delayed or erratic  if rainfall did not exceed 20-30 mm during May.  Olfert et al. (2016) ran model simulations to demonstrate how rainfall impacts wheat midge population density. Our wheat midge model (Olfert et al. 2020) indicates that dry conditions may result in:
    a. Delayed adult emergence and oviposition 
    b. Reduced numbers of adults and eggs

As of June 14, 2020, wheat midge model runs indicate that recent rainfall in Alberta and the Parkland region of Saskatchewan has resulted in movement of more than 80% of the larval population to the soil surface. Dryer conditions in other parts of Saskatchewan and in Manitoba continue to delay movement of larvae to the soil surface.  If dry conditions persist, this may result in delayed pupation and adult emergence.  

Figure 1. Predicted  percent of larval population of wheat midge (Sitodiplosis mosellana) at soil surface across
the Canadian prairies (as of June 14, 2020).

Information related to wheat midge biology and monitoring can be accessed by linking to your provincial fact sheet (Saskatchewan Agriculture or Alberta Agriculture & Forestry).  A review of wheat midge on the Canadian prairies was published by Elliott, Olfert, and Hartley in 2011.  

Alberta Agriculture and Forestry has a YouTube video describing in-field monitoring for wheat midge.  

More information about Wheat midge 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 ONLY the Wheat midge pages but remember the guide is available as a free downloadable document as both an English-enhanced or French-enhanced version.