Ross Weiss, David Giffen, Owen Olfert and Meghan Vankosky
Categories
Week 9
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.
Ross Weiss, David Giffen, Owen Olfert and Meghan Vankosky
Categories
Week 9
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.
Ross Weiss, David Giffen, Owen Olfert and Meghan Vankosky
Categories
Week 9
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”.
Ross Weiss, David Giffen, Owen Olfert and Meghan Vankosky
Categories
Week 9
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.
Ross Weiss, David Giffen, Owen Olfert and Meghan Vankosky
Categories
Week 9
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-enhancedor French-enhanced version.
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.
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.
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.
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.
• 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.
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 06Jun2019) but follow the hyperlink to check the interactive map. They are in Manitoba!
The case of the innocuous versus the evil twin: When making pest management decisions, be sure that the suspect is a actually a pest. This can be challenge since insects often mimic each other or look very similar. An insect that looks, moves and acts like a pest may in fact be a look-alike or doppelganger.
Doppelgangers may be related (e.g. same genus) or may not be related, as in the case monarch butterflies (Danaus plexippus) and viceroys (Limenitis achrippus). In some cases, doppelgangers are relatively harmless. In others, the doppelganger is a pest too yet behaviour, lifecycle and hosts may be different.
Correctly identifying a pest enables selection of the most accurate scouting or monitoring protocol. Identification and monitoring enables the application of economic thresholds. It also enables a producer to select and apply the most effective control option(s) including method and timing of application. For the rest of the growing season, the Insect of the Week will feature insect crop pests and their doppelgangers.
The case of the pea weevil and other Sitona species doppelgangers
Weevils of the genus Sitona are broad-nosed weevils that are pests of various legume crops, including field pea, faba bean, alfalfa and sweet clover. Sitona larvae attack the roots of the host plant and usually consume the root nodules and the enclosed symbiotic bacteria that fix nitrogen. Adult Sitona weevils consume plant leaves resulting in ‘U’-shaped feeding notches. Sitona species known to occur in Canada include:
• Sitona lineatus – pea leaf weevil (Fig. 1), has two primary hosts: field pea and faba bean. • Sitona cylindricollis– clover root weevil or sweet clover weevil (Fig. 4). • Sitona hispidulus – clover root curculio* (Fig. 3), a clover pest. • Sitona lineellus – alfalfa curculio (Fig. 5), eats alfalfa, vetch and field pea. • Sitona obsoletus (=S. flavescens = S. lepidus) – clover root curculio*, a clover pest (Fig. 6).
* Note that common names can be used to describe more than one species and can be confusing.
Figure 1. Pea leaf weevil (Sitona lineatus L.). Photo: AAFC-Sasktoon-Williams.
The above five Sitona species found in Canada are doppelgangers of each other for several reasons:
1. Similar in size and appearance – Require a taxonomic key and microscope to accurately identify to species. Notable difference is Sitona hispidulus which has hairy elytra compared to the other four species which lack hair on their elytra (Fig. 2).
2. Sitona weevils share primary and secondary hosts – Pea leaf weevils must feed on primary hosts (i.e., field pea and faba bean) to attain sexual maturation AND the larvae must feed on primary hosts to successfully develop. However, early in the spring and again in the fall, pea leaf weevils feed on virtually any species of legume, including the primary host plants of the other four Sitona species.
3. Foliar feeding damage is similar – According to Weich and Clements (1992), “careful scrutiny” is required to differentiate the feeding damage caused by different Sitona species feeding on the same host plant. Therefore, it is important to collect adult weevils for identification to confirm which species is responsible for foliar damage.
Figure 6. Clover root curculio (Sitona obsoletus). Photo: by K. Walker
More information about pea leaf weevil (Sitona lineatus), and sweetclover weevil (Sitona cylindricollis) can be accessed on the Insect of the Week page. Information related to crop pests and their natural enemies can be found in the newly updated Field Guide and Cutworm Guide. Both are available for free download on our Insect Field Guide and Cutworm Field Guide pages.
Ross Weiss, Serge Trudel, David Giffen and Meghan Vankosky
Categories
Week 9
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:
DAILY REPORTS, as they can be generated, are accessible as a downloadable PDF file on this page.
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, 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.
