Welcome to the first Weekly Update for the 2023 growing Season!
As planting and insect scouting are just getting started, this Weekly Update focuses on two important insects to watch out for early in the season, grasshoppers and alfalfa weevil. The first Insect of the Week (which unfortunately did not get emailed out earlier this week) is a timely reminder to watch out for flea beetles.
The prairie-wide maps summarizing the results from the 2022 growing season are online and available for review, as are the historical insect pest distribution maps. These prairie-wide geospatial maps offer insight into potential risk and help growers prioritize their scouting lists.
Remember, insect Monitoring Protocols containing helpful insect pest biology, how and when to target in-field scouting, and even thresholds to help support in-field management decisions are all available for review or download.
Wishing everyone good weather and let the insect scouting begin!
Questions or problems accessing the contents of this Weekly Update? Please contact Dr. Meghan Vankosky (meghan.vankosky@agr.gc.ca) to get connected to our information. Past “Weekly Updates” can be accessed on our Weekly Update page.
Since April 1, the 2023 growing season has been cooler than average and marginally wetter than normal. It has been coolest across Manitoba and central Saskatchewan (Fig. 1). This past week (May 1-7, 2023), the average temperature across the prairies was 5°C warmer than normal (Fig. 2). Temperatures were warmest across Alberta and western Saskatchewan and cooler over eastern Saskatchewan and Manitoba.
Figure 1. Growing season average temperature (°C) observed across the Canadian prairies for the period of April 1 to May 7, 2023.Figure 2. Seven-day average temperature (°C) observed across the Canadian prairies for the period of May 1-7, 2023.
Growing season rainfall has been near normal across most of the prairies so far in 2023, with the greatest accumulations reported across southern Manitoba and Saskatchewan (Fig. 3). Between May 1 and May 7, 2023, the 7-day cumulative rainfall was marginal across most of the prairies (Fig. 4).
Figure 3. Growing season cumulative rainfall (mm) observed across the Canadian prairies for the period of April 1 to May 7, 2023.Figure 4. Seven-day cumulative rainfall (mm) observed across the Canadian prairies for the period of May 1-7, 2023.
The grasshopper model predicts development of the migratory grasshopper (Melanoplus sanguinipes) and closely related species using biological parameters known for the pest species and environmental data observed across the Canadian prairies on a daily basis. Review lifecycle and damage information for this pest. Review the historical grasshopper maps based on late-summer adult in-field counts performed across the prairies. Results from the 2022 late-summer adult grasshopper survey are shown in Fig. 1.
Figure 1. Adult grasshopper densities in late summer of 2022.
Model simulations were used to estimate development of grasshopper eggs as of May 7, 2023. Compared with average spring temperatures, well above normal temperatures in Alberta and western Saskatchewan thus far this spring are predicted to result in rapid grasshopper egg development (Fig. 2). As a result, grasshopper egg development in 2023 is expected to be advanced as compared to egg development in average growing seasons (Fig. 3). Cool conditions in Manitoba have resulted in slower rates of egg development. Areas with the highest adult grasshopper densities in summer 2022 (Fig. 1) overlap with regions where egg development is predicted to be most advanced so far in spring 2023 (Fig. 2). Based on the 2022 survey, high densities were reported across a large region that extended south of the Yellowhead Highway corridor to the Canada-USA border (Fig. 1).
Prairie farmers should be prepared to scout for grasshoppers in spring and early summer this year, especially if conditions remain warmer and drier than normal.
Figure 2. Predicted grasshopper (Melanoplus sanguinipes) embryological development across the Canadian Prairies as of May 7, 2023.Figure 3. Long-term average predicted grasshopper (Melanoplus sanguinipes) embryological development across the Canadian prairies as of May 7, 2023, based on climate normals data.
The alfalfa weevil (AAW), Hypera postica, model predicts development using biological parameters known for the pest species and environmental data observed across the Canadian prairies on a daily basis. Review lifecycle and damage information for this pest.
Model simulations for alfalfa weevil (AAW), Hypera postica, indicate that oviposition should be underway across the prairies. Relative to eastern Saskatchewan and Manitoba, warmer temperatures in Alberta are predicted to have resulted in rapid development of alfalfa weevil populations. The following graphs indicate, based on potential number of eggs, that development of alfalfa weevil populations is greater near Lethbridge (Fig. 1) than Regina (Fig. 2). As of May 7, 2023, alfalfa weevil populations may have produced two or three times more eggs in the Lethbridge area than alfalfa weevil populations near Regina. The model predicts that hatch may occur across southern Alberta in mid-May and 10 days later across south-central Saskatchewan.
Figure 1. Predicted status of alfalfa weevil populations near Lethbridge, Alberta as of May 7, 2023.Figure 2. Predicted status of alfalfa weevil populations near Regina, Saskatchewan as of May 7, 2023.
AMANDA JORGENSEN, SHELBY DUFTON, JENNIFER OTANI, AND MEGHAN VANKOSKY*
The 2023 Insect of the Week season kicks off by featuring these small yet economically important beetles. Flea beetles have already been spotted across the prairies. Growers need to be wary of flea beetles even in the initial 7 days following seeding of their host crops, including canola. The best defense is in-field scouting from germination until the first true leaves unfurl and enlarge in size beyond the cotyledon leaf area. The adults create shot-hole damage visible on the topsides of the highly vulnerable cotyledons of canola but careful scouting also involves checking for feeding damage on the undersides of cotyledons and tiny canola stems where they also can feed.
Crucifer Beetle on Canola Leaf — photo credit: Whitney Cranshaw, Colorado State University, Bugwood.org
Several species of flea beetles are present across the Canadian prairies and not all are considered pests. Historically, crucifer (Phyllotreta crucifer), striped (Phyllotreta striolata), and hops (Psylliodes punctulata) flea beetle species have caused damage in canola. Over the past decade, the bluish-black crucifer and black-with-yellow-lined striped flea beetles have proven to be consistent economic pests in canola grown across the Canadian prairies.
Striped and crucifer flea beetles feed on canola, mustard and related cruciferous plants and weeds. Canola is highly susceptible to feeding damage at the cotyledon stage – damage appears as ‘shot-holes’ in cotyledon leaves. Flea beetles also feed on stems and very young seedlings may wilt or break off under windy or damp conditions. New generation adults feed on maturing pods late in the summer. Remember, the Action Threshold for flea beetles on canola is when 25% of cotyledon leaf area is consumed.
*Information here was compiled from past PPMN Insect of the Week feature articles about flea beetles.
Key links for more information and to aid in field scouting include:
Week 1 for the 2022 growing season and welcome back!
Seeders AND the many field crop entomologists across the Canadian prairies are out and raring to go for another growing season! This week….
Please take a moment to review the historicalRisk Maps for our most economically important insect pests of field crops on the Canadian prairies. These prairie-wide geospatial maps offer insight into potential risk and help growers prioritize their scouting lists.
Remember, insect Monitoring Protocols containing helpful insect pest biology, how and when to target in-field scouting, and even thresholds to help support in-field management decisions are all available for review or download.
NEW for this growing season – the website has been updated to create a Field Guides page linking to free, downloadable, AND searchable PDF copies of some of the key field guides used to support in-field insect monitoring in field crops on the Canadian prairies.
Be sure to catch this week’s earlier Insect of the Weekfor Week 1- it’s Flea beetles!
Wishing everyone good weather and let the insect scouting begin!
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.
TEMPERATURE: Since April 1, the 2022 growing season has been cooler and wetter than normal. This past week (May 2-8, 2022), the average temperature across the prairies was 1.1 °C cooler than normal (Fig. 1). The average 30-day temperature (April 9-May 8, 2022) was 3 °C lower than climate normal values (Fig. 1). Temperatures have been coolest in Manitoba (Figs. 1, 2).
Figure 1. 30-day average temperature (°C) observed across the Canadian prairies for the period of April 9– May 8, 2022.Figure 2. Seven-day average temperature (°C) across the Canadian prairies for the period of May 2-8, 2022.
Growing degree day (GDD) maps for Base 5 ºC and Base 10 ºC (April 1-May 9, 2022) can be viewed by clicking the hyperlinks. Over the past 7 days (May 3-9, 2022), the lowest temperatures recorded across the Canadian prairies ranged from < -12 to >0 °C while the highest temperatures observed ranged from <10 to >25 °C. Even at this early point in the growing season, a few areas in Alberta and Saskatchewan have experienced 1-2 days >25 °C (view map). Access these maps and more using the AAFC Maps of Historic Agroclimate Conditions interface.
PRECIPITATION: Average seven-day cumulative rainfall ranged between 0 and 66 mm with the highest rainfall amounts occurring in the Peace River region of Alberta and British Columbia (Fig. 3). The remainder of the prairies received little or no rain. Rain (30-day accumulation) amounts have been well above average for most of the prairies (255 % of average). Rainfall for April 9-May 8, 2022 was greatest across Manitoba and conditions have been drier across most of Saskatchewan and Alberta (Fig. 4).
Figure 3. Seven-day cumulative rainfall (mm) observed across the Canadian prairies for the period of May 2-8, 2022.Figure 4. 30-day cumulative rainfall (mm) observed across the Canadian prairies for the period of April 9-May 8, 2022.
The alfalfa weevil (AAW) (Curculionidae: Hypera postica) model predicts development using biological parameters known for the pest species and environmental data observed across the Canadian prairies on a daily basis. Review lifecycle and damage information for this pest.
As of May 8, model simulations for alfalfa weevil (AAW) predict that oviposition is well underway across the prairies. The following graphs indicate, based on the potential number of eggs, that development is slower near Lethbridge (Fig. 1) than Saskatoon (Fig. 2). Development for both locations is ahead of that expected based on long-term averages. The model predicts that hatch may occur during the last week of May.
Figure 1. Predicted status of alfalfa weevil (Hypera postica) populations near Lethbridge AB as of May 8, 2022.Figure 2. Predicted status of alfalfa weevil (Hypera postica) populations near Saskatoon SK as of May 8, 2022.
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 as a free downloadable PDF in either English or French on our new Field Guides page.
The cereal leaf beetle (CLB) (Chysomelidae: Oulema melanopus) model predicts larval development using biological parameters known for the pest species and environmental data observed across the Canadian prairies on a daily basis. Review lifecycle and damage information for this pest.
As of May 8, 2022, the model output suggests that overwintered adults are active and that oviposition is underway across the southern regions of Alberta and in southwestern western Saskatchewan. Compared to simulations for climate normals, development in 2022 is generally slower than average. The graphs provide a comparison of development for Lethbridge (Fig. 1) and Swift Current (Fig. 2).
Warmer conditions in southern Alberta are predicted to result in more rapid development of CLB populations in comparison to southern Saskatchewan. The simulation indicates that first instar larvae may occur during the third week of May.
Figure 1. Predicted status of cereal leaf beetle (Oulema melanopus) populations near Lethbridge AB as of May 8, 2022. Figure 2. Predicted status of cereal leaf beetle (Oulema melanopus) populations near Swift Current SK as of May 8, 2022.
Access scouting tips for cereal leaf beetle or find more detailed information by accessing 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 as a free downloadable PDF in either English or French on our new Field Guides page.
The grasshopper (Acrididae: Melanoplus sanguinipes) model predicts development using biological parameters known for the pest species and environmental data observed across the Canadian prairies on a daily basis. Review lifecycle and damage information for this pest. Review the historical grasshopper maps based on late-summer adult in-field counts performed across the prairies.
As of May 8, 2022, the model simulation indicates that egg development is most advanced in southern Alberta (Fig. 1). Cool conditions in Manitoba have resulted in slower development rates. Egg development is expected to range from 50 and 65 % across most of the prairies (average = 59 %). Based on climate normals data, long-term average development should be 57 % (Fig. 2).
Figure 1. Predicted grasshopper (Melanoplus sanguinipes) embryological development across the Canadian prairies as of May 8, 2022.Figure 2. Predicted grasshopper (Melanoplus sanguinipes) embryological development across the Canadian prairies as of May 8 based on long-term average (climate normals) data.
SASKATCHEWAN’SCrop Production News normally includes 7 issues released through the growing season. Be sure to bookmark their insect pest homepage to access important information!
ALBERTA’SInsect Pest Monitoring Network webpage links to insect survey maps, live feed maps, insect trap set-up videos, and more. There is also a Major Crops Insect webpage. The new webpage does not replace the Insect Pest Monitoring Network page. Remember, AAF’s Agri-News occasionally includes insect-related information. Twitter users can connect to #ABBugChat Wednesdays at 10:00 am. • Diamondback moth pheromone trap monitoring update for AB – Cumulative counts arising from weekly data are available so refer to the Live Map.
Shot-hole feeding on seedling canola is NOT a pretty sight in newly emerging stands but growers need to be wary of flea beetles even in the initial 7 days following seeding. The best defense is in-field scouting which continues from germination until the first true leaves unfurl and enlarge in size beyond the cotyledon leaf area. Overwintered adults are highly mobile and attracted to yellow. They even orient towards kairomones released by canola and other closely related Brassicaceae.
Adults are defoliators and small in size, ranging 2-3 mm in length. Even so, the combination of high densities of flea beetles and adverse growing conditions that slow canola seedling growth and extend the vulnerable number of days plants remain seedlings. In some cases, daily in-field monitoring may be necessary to protect canola seedlings from high densities of flea beetles that move into a field en masse.
Crucifer Beetle on Canola Leaf — photo credit: Whitney Cranshaw, Colorado State University, Bugwood.org
Several species of flea beetles are present across the Canadian prairies and not all are considered pests. Historically, crucifer (Phyllotreta crucifer), striped (Phyllotreta striolata), and hops (Psylliodes punctulata) flea beetle species have caused damage in canola. Over the past decade, the bluish-black crucifer and especially black-with-yellow-lined striped flea beetles have proven to be consistent economic pests in canola grown across the Canadian prairies.
The 2022 Insect of the Week kicks off by featuring these small yet economically important 2-3 mm long beetles. The adults create shot-hole damage visible on the topsides of the highly vulnerable cotyledons of canola but careful scouting also involves checking for feeding damage on the undersides of cotyledons and tiny stem where they also can feed.
Striped Flea Beetle–Photo: Mike Dolinski, MikeDolinski@hotmail.com
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!
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.
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=trueFigure 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=trueFigure 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).
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.
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.
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).
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:
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!
• 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 Forestry – NEW 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.
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.
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.
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.
We hope everyone is doing well and coping with this extraordinary spring. The Weekly Update is back for 2020 although changes are coming this growing season! The popular Insect of the Week feature will return soon but today we are pleased to share Week 1 of the Weekly Updates for 2020!
April’s information will focus on wind trajectories related to the prairie provinces. This is an important tool used to track potential arrival events for pest species moving northerly into the Canadian prairies from more southerly points of origin (e.g., diamondback moth, aster leafhoppers).
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. 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. We receive two types of model output from ECCC: reverse trajectories and forward trajectories.
‘Reverse trajectories’ (RT) refer to air currents that are tracked back in time from specified Canadian locations over a five-day period prior to their arrival date. Of particular interest are those trajectories that, prior to their arrival in Canada, originated over northwestern and southern USA and Mexico, anywhere diamondback moth populations overwinter and adults are actively migrating. If diamondback adults are present in the air currents that originate from these southern locations, the moths may be deposited on the Prairies at sites along the trajectory, depending on the local weather conditions at the time that the trajectories pass over our area (e.g. rain showers, etc.). Reverse trajectories are the best available estimate of the ”true” 3D wind fields at a specific point. They are based on observations, satellite and radiosonde data.
‘Forward trajectories’ (FT) have a similar purpose; however, the modelling process begins at sites in USA & Mexico. The model output predicts the pathway of a trajectory. Again, of interest to us are the winds that eventually end up passing over the Prairies.
Ross Weiss (AAFC), Meghan Vankosky (AAFC) and Serge Trudel (ECCC)
DATE: APRIL 8, 2019
1. Reverse trajectories (RT): a. Pacific Northwest (PNW) – For the period of April 2-8 there have been 69 RT’s (originating over the PNW) that have crossed over prairie locations. Since March 23rd Lethbridge has reported the highest number of PNW RT’s (n=9), followed by Olds AB, Beiseker AB and Dauphin MB (n=6).
List of PNW Reverse trajectories that have crossed the prairies (Since March 23, 2019):
b. Mexico and SW USA (SW) – On April 7 the first Southwestern USA and Mexico RT’s crossed the prairies. These reverse trajectories originated over TX and CA.
The following maps present two examples of April 7, 2019 RT’s. The first map indicates that the RT crossing Tisdale originated across southern TX. The second map shows that two RT’s crossed over Regina. The red line indicates that this RT originated over southern TX. A second RT originated across central CA.
Tisdale SK, April 7, 2019
Regina SK, April 7, 2019
2. Forward trajectories (FT) –
The following table reports the origin of forward trajectories predicted to cross the prairies over the next five days. Forward trajectories, originating over Santa Maria, CA are predicted to pass over SK and MB in the next five days.
Weather synopsis – We begin with a synopsis of the weather situation starting with the map below reflecting the Accumulated Precipitation received during the winter (Nov 1, 2017 to Mar 31, 2018) across the prairies (Figure 1).
Figure 1. Accumulated precipitation across the Canadian prairies during the winter (November 1, 2017-March 31, 2018.
Prairie meteorological conditions continue to be cooler and dryer than average. This past week the average temperature was about 1 °C cooler than normal (Fig. 2). The 30-day average temperature (April 6-May 6) was 4 °C cooler than normal (Figs. 3 and 4). Weekly and 30 day total rainfall is approximately 50% less than average (Figs. 5 and 6).
Figure 2. Average temperatures across the Canadian prairies these past seven days (Apr 29-May 6, 2018).
Figure 3. Average temperatures across the Canadian prairies these past 30 days (Apr 6-May 6, 2018).
Figure 4. Monthly mean temperature differences across the Canadian prairies for the month of April 2018.
Figure 5 Accumulated precipitation across the Canadian prairies these past seven days (Apr 29-May 6, 2018).
Figure 6. Accumulated precipitation across the Canadian prairies these past 30 days (Apr 6-May 6, 2018).
The map below reflects the Highest Temperatures occurring over the past 7 days across the prairies.
The map below reflects the Lowest Temperatures occurring over the past 7 days across the prairies.
The growing degree day map (GDD) (Base 10ºC, March 1 – May 6, 2018) is below:
The growing degree day map (GDD) (Base 5ºC, March 1 – May 6, 2018) is below:
The maps above are all produced by Agriculture and Agri-Food Canada. Growers may wish to bookmark the AAFC Drought Watch Maps for the growing season.
Background. 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 1990’s. 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.
We receive two types of model output from ECCC: reverse trajectories (RT) and forward trajectories (FT): (i) Reverse trajectories refer to air currents that are tracked back in time from specified Canadian locations over a five-day period prior to their arrival date. Of particular interest are those trajectories that, prior to their arrival in Canada, originated over northwestern and southern USA and Mexico, anywhere diamondback moth populations overwinter and adults are actively migrating. If diamondback adults are present in the air currents that originate from these southern locations, the moths may be deposited on the Prairies at sites along the trajectory, depending on the local weather conditions at the time that the trajectories pass over our area (e.g. rain showers, etc.). RTs are the best available estimate of 3D wind fields at a specific point. They are based on observations, satellite and radiosonde data.
(ii) Forward trajectories have a similar purpose; however, the modelling process begins at sites in USA and Mexico. The model output predicts the pathway of a trajectory. Again, of interest to us are the winds that eventually end up passing over the Prairies.
Current Data
Pacific Northwest (PNW) – The number of RTs predicted to cross the prairies from the PNW, has increased over the last few days. Model runs for May 7th predicted that seven RTs will cross over AB and SK in the next 24 hours from the PNW. Based on results for April, there have been fewer RTs in 2018 than 2017. The number of RTs were greatest across southern AB (Fig. 1). The majority of these crossed the prairies in mid-April (Fig. 2).
Figure 1. Total number of reverse trajectories, originating over the US PNW, that
has entered the prairies during April, 2018.
Figure 2. Daily total number of reverse trajectories, originating over the US PNW, that
have entered the prairies during April, 2018.
Cutworms (Noctuidae) – A field guide is now available to help growers scout and manage Cutworms! Cutworm Pest of Crops is available for free in either English or French and is posted on the Cutworm Field Guide page! Also be sure to check the Insect of the Week through May – it highlights cutworms.
Several species of cutworms can be present in fields. They range in colour from shiny opaque, to tan, to brownish-red with chevron patterning. Cutworm biology, species information, plus monitoring recommendations are available in the Prairie Pest Monitoring Network’s Cutworm Monitoring Protocol. Also refer to Manitoba Agriculture cutworm fact sheet which includes action and economic thresholds for cutworms in several crops. Scout fields that are “slow” to emerge, are missing rows, include wilting or yellowing plants, have bare patches, or appear highly attractive to birds – these are areas warranting a closer look. Plan to follow-up by walking these areas later in the day when some cutworm species move above-ground to feed. Start to dig below the soil surface (1-5 cm deep) near the base of a symptomatic plant or the adjacent healthy plant. If the plant is well-established, check within the crown in addition to the adjacent soil. The culprits could be wireworms or cutworms. For Albertans….. If you find cutworms, please consider using the Alberta Pest Surveillance Network’s “2018 Cutworm Reporting Tool”. Once data entry occurs, growers can view the live 2018 cutworm map which is updated daily.
Flea Beetles (Chrysomelidae: Phyllotreta species) – Be on the lookout for flea beetle damage resulting from feeding on canola cotyledons but also on the stem. Two species, Phyllotreta striolata and P. cruciferae, will feed on all cruciferous plants but they can cause economic levels of damage in canola during the seedling stages.
Remember, the Action Threshold for flea beetles on canola is 25% of cotyledon leaf area consumed. Watch for shot-hole feeding in seedling canola but also watch the growing point and stems of seedlings which are particularly vulnerable to flea beetle feeding. Estimating flea beetle feeding damage can be challenging. Using a visual guide to estimate damage can be helpful. Canola Watch circulated this article but also use the two images (copied below for reference) produced by Dr. J. Soroka (AAFC-Saskatoon) – take it scouting!
Figure 1. Canola cotyledons with various percentages of leaf area consume owing to flea beetle feeding damage (Photo: Soroka & Underwood, AAFC-Saskatoon).
Figure 2. Percent leaf area consumed by flea beetles feeding on canola seedlings (Photo: Soroka & Underwood, AAFC-Saskatoon).
Refer to the flea beetle page from the “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 (Oulema melanopus) – Model output indicates that CLB oviposition has begun in many locations. As of May 6th, CLB model runs indicated that cool temperatures have delayed oviposition (compared to long term average) in Lethbridge, but more advanced in Swift Current, Brandon and Saskatoon (Fig. 1).
Figure 1. Predicted CLB oviposition at four prairie locations. Values are based on model simulations, for April 1 – May 6, 2018.
Lifecycle and Damage:
Adult: Adult cereal leaf beetles (CLB) have shiny bluish-black wing-covers (Fig. 1). 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 1. 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. 2). When the larva completes its growth, it drops to the ground and pupates in the soil.
Figure 2. 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”.
Pea Leaf Weevil (Sitona lineatus) – The PLW model predicts that adults are emerging from overwintering sites and beginning to fly. This is similar to model output based on long term (climate) data. Looking forward, based on long term average climate data, oviposition should occur in late May or early June (Fig. 1).
Figure 1. Predicted PLW phenology at Swift Current based on long term climate data. Values are
based on model simulations (April 1 – May 6).
Pea leaf weevils emerge in the spring primarily by flying (at temperatures above 17ºC) or they may walk short distances. Pea leaf weevil movement into peas and faba beans is achieved primarily through flight. Adults are slender, greyish-brown measuring approximately 5 mm in length (Fig. 1, Left). The pea leaf weevil resembles the sweet clover weevil (Sitona cylindricollis) but the former is distinguished by three light-coloured stripes extending length-wise down thorax and sometimes the abdomen. All species of Sitona, including the pea leaf weevil, have a short snout.
Figure 1. Comparison images and descriptions of four Sitona species adults including pea leaf weevil (Left).
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.
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 May 6, 2018, predicted mean development was 62% (slightly greater than long term average of 56%). The greatest development was predicted to be across southern AB (Fig. 1).
Figure 1. Grasshopper embryological development (%) based on model simulations, for April 1 – May 6, 2018.
Reminder – The Prairie Pest Monitoring Network’s 2018 Grasshopper Forecast Map was released in March. Review all the risk and forecast maps by linking here. While spring temperatures, soil moisture conditions, and precipitation can all have an impact on overwintered grasshopper eggs, growers in areas highlighted orange or red in the map below should be vigilant this spring. 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 (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 (Hypera postica) across the prairies are updated weekly to help growers time their in-field scouting for second-instar larvae. Compare the following predicted development stages and degree-day values from Soroka (2015) to the map below.
The AAW model predicts that oviposition may have begun in southern areas of the prairies. Current oviposition rates are predicted to be higher than oviposition rates based on LTN climate data (Fig. 1).
Figure 1. Predicted AAW oviposition at four prairie locations. Values are based on
model simulations, for April 1 – May 6, 2018.
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.
Use the photo below as a visual reference to identify alfalfa weevil larvae. Note the white dorsal line, the tapered shape of the abdomen and the dark head capsule.
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.
Bertha armyworm (Lepidoptera: Mamestra configurata) – Bertha armyworm pupal development is predicted below. The map illustrates that overwintered BAW are beginning to develop within their pupa located in the soil but are still several weeks away from emerging as moths.
Field scouting is critical – it enables the identification of potential risks to crops. Accurate identification of insect pests PLUS the application of established monitoring methods will enable growers to make informed pest management decisions. We offer TWO generalized insect pest scouting charts to aid in-field scouting on the Canadian prairies: 1. CANOLA INSECT SCOUTING CHART 2. A NEW FLAX INSECT SCOUTING CHART These charts feature hyperlinks directing growers to downloadable PDF pages within the “Field crop and forage pests and their natural enemies in western Canada: Identification and management field guide“. Whenever possible, monitor and compare pest densities to established economic or action thresholds to protect and preserve pollinators and beneficial arthropods. Economic thresholds, by definition, help growers avoid crop losses related to outbreaking insect pest species. Good luck with your scouting!
Aphids can cause significant damage to fields and increase crop losses, but just because aphids are present in a grain field doesn’t mean they will have a negative economic impact on production. This is especially true if there are aphid’s natural enemies (beneficial insects) in the field to keep them under control.
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 (Agriculture and Agri-Food Canada Field Crop Entomologist) 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.
Greetings! The Prairie Pest Monitoring Network’s Blog gears up for the 2018 growing season this week! Today the first “Insect of the Week” was released and watch for the first “Weekly Update” on Friday morning!
This week’s insect is the glassy cutworm. The larva is greyish-white, semi-translucent and shiny (i.e. glass-like) with a orange-brown head. Since it overwinters as a larva, it is active as soon as the ground thaws. It feeds underground and rarely come to the surface. Their main host crop are grasses but will also attack wheat and corn. Corn planted following wheat may be particularly at risk.
Other important species include dingy, army, redbacked and pale western cutworms (See Insect of the Week: 2017 – May 1, 8, 15 and 29).
In addition, Cutworm Pests of Crops on the Canadian Prairies – Identification and Management Field Guide was just published (2017). This new handy field guide has chapters on general biology, history of outbreaks, scouting techniques, natural enemies and general control options. The guide includes descriptions of 24 cutworm species, their lifecycle, hosts, damage, monitoring and economic thresholds. To download a copy, go to the Cutworm Field Guide page.
For many, seed isn’t even in the ground yet, but the cutworms are ready for it when it is. 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. Species-specific protocols can be found in the new Cutworm Pests of Crops on the Canadian Prairies (see below for download details).
There are over 20 cutworm species that may cause economic damage to your crop, each with different feeding behaviour, preferred hosts and lifecycle. This is why species identification is so important: it helps growers understand what they are up against: determining how and when to scout, knowing whether the cutworm species is found above-ground (climbing) or below-ground, recognizing damage, choosing control options. Species also impacts the most appropriate time of day for monitoring and applying controls.
Action and economic thresholds do exist for many of the cutworm species – please use them. This will help control costs by eliminating unnecessary/un-economic sprays and reduce your impact on non-target insects – insects that include cutworm natural enemies that work in the background to control cutworm populations.
This week’s Insect of the Week is the Pale Western Cutworm. This is a below-ground feeder. Larvae hatch in late April/early May. As they feed on/tunnel through shoots as they pass through the soil, young larvae produce holes on newly-emerged shoots and furled leaves . Older larvae will sever plants just below the soil surface and may pull and eat the severed shoots underground.
For more information about Pale Western Cutworm, go to the Insect of Week page.
Pale western cutwom. cc-by-nc 3.0 Frank Peairs,
Colorado State University, bugwood.org
It’s Spring and the Weekly Update is back for the 2017 growing season in Blog form! A downloadable PDF version of the complete Weekly Update for Week 1 (May 4, 2017) can be accessed here.
Questions or problems accessing the contents of this Weekly Update? Please e-mail either Dr. Owen Olfert or Jennifer Otani. Past “Weekly Updates” are very kindly archived can be accessed on our Weekly Update page.
Weather synopsis – We begin with a synopsis of the weather situation starting with the map below which reflects the Accumulated Precipitation received during the winter (Nov 1, 2016 to Mar 31, 2017) across the prairies (Figure 1).
Figure 1. Accumulated precipitation across the Canadian prairies during the winter (November 1, 2016-March 31, 2017).
Average temperatures over the past month have been warmest across the southern prairies. April precipitation was greater across Manitoba and eastern Saskatchewan than western Saskatchewan or Alberta (Figure 2). Compared to last year at this time, April 2017 was approximately 2°C cooler with marginally greater precipitation than last year (prairie-wide average values; Figure 3).
Figure 2. Average temperatures across the Canadian prairies the past 30 days (April 1-30, 2017).
Figure 3. Cumulative precipitation across the Canadian prairies the past 30 days (April 1-30, 2017).
The map below reflects the Highest Temperatures occurring over the past 7 days across the prairies.
The map below reflects the Lowest Temperatures occurring over the past 7 days across the prairies.
The maps above are all produced by Agriculture and Agri-Food Canada. Growers may wish to bookmark the AAFC Drought Watch Maps for the growing season.
THE WEEK OF MAY 1, 2017: Wind trajectory data processing by AAFC-Saskatoon Staff began in April. Reverse Trajectories track arriving air masses back to their point of origin while Forward Trajectories predict favourable winds expected to arrive across the Canadian Prairies for the week of May 1, 2017: Reverse trajectories (RT) Wind trajectories have been monitored since April 1 this year. To date, winds have originated predominantly from the USA – Pacific Northwest (PNW). Overall results indicate that eastern locations on the prairies have had fewer of these winds than western locations (Figure 1). Over the last week (April 25- May 1, 2017), Lethbridge has had significantly more RT’s from the Pacific Northwest than either SK and MB sites (Figure 2).
Figure 1. Summary of reverse trajectory wind data (PNW) for the
prairies April 1-May 1, 2017.
Figure 2. Based on results for specific locations (Brandon,
Saskatoon, Lethbridge), Lethbridge has had significantly more RT’s from the
Pacific Northwest than SK and MB.
Forward trajectories (FT) Forward trajectories that were predicted to cross the prairies from the southern USA and Mexico have been limited so far. There were a few isolated days of winds from Santa Maria and Imperial Valley, CA. and from Mexicali, Mexico in mid-April.
Diamondback moth (Plutellidae: Plutella xylostella) – Pheromone traps attracting male Diamondback moths are being deployed across the prairies. High altitude air masses are tracked by AAFC-Saskatoon Staff (forward and backward trajectories). These wind events have the potential to aid the movement of diamondback moth and aster leafhoppers northward on to the Canadian prairies from Mexico, southern and central USA as well as the Pacific Northwest. Diamondback moth pheromone traps deployed across the prairies confirm their arrival – many thanks to the people who deploy and do the weekly monitoring!
More information about Diamondback moths 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 Diamondback moth page but remember the guide is available as a free downloadable document as both an English-enhanced or French-enhanced version.
Cutworms (Noctuidae) – NEW – Just in time for spring scouting! A new field guide is now available to help growers scout and manage Cutworms! Cutworm Pest of Crops is now available for free in either English or French and is featured at our newCutworm Field Guide! Also be sure to check the Insect of the Week throughout May – it highlights cutworms through May. Be sure to read more about Pale western cutworms.
Several species of cutworms can be present in fields. They range in colour from shiny opaque, to tan, to brownish-red with chevron patterning. Cutworm biology, species information, plus monitoring recommendations are available in the Prairie Pest Monitoring Network’s Cutworm Monitoring Protocol. Also refer to Manitoba Agriculture and Rural Initiatives cutworm fact sheet which includes action and economic thresholds for cutworms in several crops.
Keep an eye on fields that are “slow” to emerge, are missing rows, include wilting or yellowing plants, have bare patches, or appear highly attractive to birds – these are areas warranting a closer look. Plan to follow-up by walking these areas later in the day when some cutworm species move above-ground to feed. Start to dig below the soil surface (1-5 cm deep) near the base of a symptomatic plant or the adjacent healthy plant. If the plant is well-established, check within the crown in addition to the adjacent soil. The culprits could be wireworms or cutworms. For Albertans….. If you find cutworms, please consider using the Alberta Pest Surveillance Network’s “2017 Cutworm Reporting Tool”. Once data entry occurs, growers can view the live 2017 cutworm map which is updated daily.
Cereal leaf beetle (Oulema melanopus) – As of May 1, 2017, the CLB model indicates that oviposition has begun in the Lethbridge and Swift Current areas.
Lifecycle and Damage: Adult: Adult cereal leaf beetles (CLB) have shiny bluish-black wing-covers (Fig. 1). 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 1. Adult Oulema melanopus (~4.4-5.5 mm long).
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. 2). When the larva completes its growth, it drops to the ground and pupates in the soil.
Figure 2. Larval stage of Oulema melanopus with characteristic feeding damage visible on leaf.
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”.
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 May 1, 2017, model output predicted embryological mean development was 56%; the greatest development was predicted to be across the southern prairies. Embryological development was very similar to long term averages (57%) though marginally slower than 2016 (62%).
Reminder – The Prairie Pest Monitoring Network’s 2017 Grasshopper Forecast Map (Figure 1) was released in January. While spring temperatures, soil moisture conditions, and precipitation can all have an impact on overwintered grasshopper eggs, growers in areas highlighted orange or red in the map below should be vigilant as nymphs begin to hatch this season.
Figure 1. Prairie Pest Monitoring Network’s 2017 Grasshopper Forecast Map.
We again track the migration of the Monarch butterflies and they move north by checking the 2017 Monarch Migration Map! A screen shot of the map has been placed below as an example (retrieved 04May2017) but follow the hyperlink to check the interactive map!
And finally….. It’s time to scout! On the prairies we’re out in fields. It’s a little different for folks in Newfoundland and Labrador! Here’s the link to the first iceberg report for the 2017 season! A screen shot is below!
THE WEEK OF MAY 9, 2016: Wind trajectory data processing by AAFC-Saskatoon Staff began in April. Reverse Trajectories track arriving air masses back to their point of origin while Forward Trajectories predict favourable winds expected to arrive across the Canadian Prairies for the week of May 9, 2016: Reverse trajectories (RT) Naicam, Regina, Tisdale (Saskatchewan) and Lethbridge, Beiseker (Alberta) had the first occurrences of Reverse Trajectories this week that originated from southwestern USA and /or Mexico.
Forward Trajectories (FT) There are four forward trajectories from California and Texas that are predicted to cross the prairies over the next 5 days. Below is a map of the sites from which the Forward Trajectories originated that crossed the prairies over the past month.
2016 Wind Trajectories – High altitude air masses originate from southern locations and continuously move northerly to Canadian destinations. Insect pest species such as Diamondback moth and Aster leafhoppers, traditionally unable to overwinter above the 49th parallel, can utilize these air masses in the spring to move north from Mexico and the United States (southern or Pacific northwest). Data acquired from Environment Canada is compiled by Olfert et al. (AAFC-Saskatoon) to track and model spring high altitude air masses with respect to potential introductions of insect pests onto the Canadian prairies.
Reverse Trajectories track arriving air masses back to their point of origin while Forward Trajectories predict favourable winds expected to arrive across the Canadian Prairies.
As of May 2, 2016, Reverse Trajectories (RTs) originating from Mexico and southwest USA have been arriving across the prairies:
Whereas Reverse Trajectories (RTs) originating from northwest USA have arrived over a greater area of the prairies with more RTs arriving in Alberta and the BC Peace:
Wind trajectory data processing by AAFC-Saskatoon Staff began in April and those reports were posted for:
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).
Warm, dry conditions typically enhance grasshopper egg development. The predicted mean embryological development of the migratory grasshopper (Orthoptera: Melanoplus sanguinipes) was 62% this week. The greatest development was predicted to be in Alberta (note areas shaded orange).
We begin with a synopsis of the weather situation starting with the map below which reflects the Accumulated Precipitation received during the winter (Nov 1, 2015 to Mar 31, 2016) across the prairies.
In terms of Percent of Average Precipitation received during the winter (Nov 1, 2015 to Mar 31, 2016), the map below confirms the lower levels of precipitation received across the prairies the past winter.
Across the prairies, meteorological conditions have been warm and dry during April. The map below indicates the Average Temperatures across the prairies (April 1-30, 2016).
The map below reflects the Highest Temperatures occurring over the past 7 days across the prairies.
And the map below reflects the Lowest Temperatures occurring over the past 7 days across the prairies.
Alberta has been particularly dry in April. The map below reflects the Accumulated Precipitation (April 1-30, 2016).
The Accumulated Precipitation the past 7 days (i.e., April 27-May 3, 2016) is mapped below:
The maps above are all produced by Agriculture and Agri-Food Canada. Growers may wish to bookmark the AAFC Drought Watch webpage.
Cereal leaf beetle (Chrysomelidae: Oulema melanopus) – As of May 1, 2016, the Cereal leaf beetle (CLB) model indicates that oviposition is well underway at Lethbridge AB and Maple Creek SK. Oviposition is expected to begin this week near Swan River MB. Larval populations are predicted to peak in mid-June in southern Alberta and one to two weeks later at the Saskatchewan and Manitoba locations.
Predicted dates of peak emergence of CLB eggs and larvae are as follows:
Fact sheets for CLB are published by the province of Alberta and by 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”.
Wind trajectories Related to Diamondback Moth (DBM) and Aster Leafhopper Introductions to the Canadian Prairies in 2015
BACKGROUND:Potential wind events capable of carrying insect pests from source areas in the USA can be identified by following trajectories for air parcels through time. High altitude air masses, originating from southern locations, frequently move northerly to Canadian destinations. Insect pest species such as Diamondback moth and Aster leafhoppers, traditionally unable to overwinter above the 49th parallel, can utilize these air masses in the spring to move north from Mexico and the United States (southern or Pacific northwest).
Wind trajectory data processing by AAFC-Saskatoon Staff began in April. Reverse Trajectories track air masses arriving across the prairies back to their point of origin. Forward Trajectories predict favourable winds expected to arrive across the Canadian Prairies.
Updated: May 4-5, 2015
1. Reverse trajectories
a. Pacific Northwest (PNW) – Between May 1-3, 2015, the predominate air mass source is continues to be the Pacific Northwest. Reverse trajectories model output for 10 prairie locations and indicated that winds arriving to the Canadian prairies originated from northwest USA between April 25-27, 2015.
2. Forward trajectories
Between may 1-3, 2015, there were five forward trajectories originating over Texas and California that are predicted to cross over the prairies over the 2-3 days. An example of forward trajectories for the Santa Maria CA example is below. Note how air masses are predicted to land in northeast Saskatchewan, northern Manitoba, and into Ontario.
