In Alberta, grasshopper population densities are high in the southeast and southcentral municipalities and the Agricultural Fieldmen are now starting to survey for adult grasshopper populations. There have been reports of wheat head armyworm in the central Peace River region, but there have also been Cotesia parasitoid cocoons in those fields, which is a good sign in terms of natural control of the armyworm population. Tiger moth caterpillars have also been reported in the central Peace River region; these are not typically pests but are interesting as they have been feeding on wild buckwheat.
Visit the Alberta Insect Pest Monitoring Network and Crop Insects pages for information about insects and monitoring in Alberta, including links for live maps from the 2023 monitoring season for diamondback moth, bertha armyworm, cutworms, and cabbage seedpod weevil.
Grasshopper densities are high in many parts of the prairies this year, especially now that adult grasshoppers are able to fly to disperse. With adults present, egg laying is likely to be underway. Picture by Jonathon Williams, AAFC-Saskatoon.
In Saskatchewan, grasshopper population densities are particularly high in the southern and central regions. Ripening canola crops are currently playing host to crickets (reported consuming pods), crucifer flea beetles, diamondback moth and Lygus bugs. Densities of diamondback moth and Lyugs have been economically significant in some regions, so scouting is important. Pea aphid and cereal aphid numbers appear to be increasing in some parts of the province, so scouting for these pests in their respective host crops is also important as the growing season winds down. There have been four reports of Hessian fly in Saskatchewan this summer.
Saskatchewan Crop Production News issues are now online! There are links on the Crop Production News page so that interested readers can subscribe to the newsletter or read issues from past years.
A diamondback moth larva on a canola leaf. Population densities are high in some fields and scouting is needed to avoid unpleasant surprises. Picture by Jonathon Williams, AAFC-Saskatoon.
In Manitoba, aphid population densities have been high enough to warrant control in small grain cereal crops in some regions, especially where crops were planted late and crops are still in vulnerable stages. Where there are a lot of aphids in fields, there have also been lots of lady beetle larvae and aphid mummies (resulting from aphids being attacked by parasitoids). A few fields in the Cypress River/Balder area of Manitoba have been sprayed for bertha armyworm. Some canola fields have been sprayed for diamondback moth and Lygus bugs in the Eastern region, and for diamondback moth in the Interlake region. Like in Saskatchewan, crucifer flea beetles are now active again, and are feeding on green canola. A soybean field in the Central region of Manitoba was treated for spider mites. Some insecticide applications for banded sunflower moth have occurred in the Eastern region. Grasshoppers are numerous in crops in some areas, and pastures in some areas have been sprayed for grasshoppers. John spotted some dead grasshoppers clinging to the upper leaves of plants that were infected with the pathogen Entomophaga grylii, but the incidence of infection has been low so far this year. Scout for aphids in cereal crops and for a variety of insects in canola fields.
Weekly Manitoba Crop Pest Updates for 2023 are available online with timely updates about insect pests, weeds, and plant pathogens. Watch their website for new Crop Pest Updates (usually published on Wednesdays this year).
Based on model simulations, bertha armyworm development continues to be 7-10 days ahead of normal. Where present, populations of bertha armyworm will largely be in the larval stage (Fig. 1).
Figure 1. The proportion (%) of the bertha armyworm (Mamestra configurata) population that is expected to be in the larval stage across the Canadian prairies as of July 2, 2023. Note that bertha armyworm may not be present at all locations.
The larvae of this generalist moth could be found in canola fields, but also in other crops.
The lifestages of bertha armyworm: A) eggs, B) larva, C) pupa, and D) adult. All pictures taken by Jonathon Williams, AAFC-Saskatoon (please include a photo credit if these pictures are reproduced elsewhere).
The network of pheromone traps across the prairies is reporting low numbers of adults (less than 300 cumulative catch over the last 6 weeks) so far in 2023, including in Manitoba (check out the July 5 Manitoba Crop Pest Update), Saskatchewan, and Alberta. Only one monitoring location (in Manitoba) has caught more than 300 bertha armyworm adults so far this year, suggesting relatively low risk across the prairies. Risk to yield from bertha armyworm increases when cumulative trap catches exceed 300 (300-900 = medium risk, >900 = high risk). Although the pheromone trap network suggests low risk of economic damage from bertha armyworm, it is still important to scout for larvae. For information about scouting, check out the PPMN protocol and the Alberta Agriculture and Irrigation pages.
Development of the pest grasshoppers continues to be ahead of schedule in 2023, as compared to past years. The first adult two-striped grasshoppers (Melonplus bivittatus) were collected on June 15 (Alberta) and June 19-20 (Saskatchewan). No one that we’ve spoken to remembers finding adult two-striped grasshoppers in June before. Especially in the south, densities are quite high and crop damage is being reported, as well as spraying to protect crops.
Model simulations for grasshopper development indicate that grasshoppers should range from first to fifth instars with some adults now present at many locations across the prairies, as of June 25. Based on average instar, development is most advanced across the southern prairies where 65% of the population is predicted to be fourth and 5th instar, with some adults also present (Fig. 1). In an ‘average year’, the majority of the grasshopper population (60%) would typically be in the first, second, and third instars in late June.
Figure 1. Predicted grasshopper (Melanoplus sanguinipes) development, presented as average instar, across the Canadian prairies as of June 25, 2023.
Based on occurrence of fifth instar grasshoppers, development is most advanced across southern Manitoba (Fig. 2).
Figure 2. Predicted migratory grasshopper (Melanoplus sanguinipes) development, presented as the percent of the population in the fifth instar, across the Canadian prairies as of June 25, 2023.
Adult two-striped grasshoppers (Melanoplus bivittatus) and migratory grasshoppers (M. sanguinipes) have been observed across the southern prairies.
Last week, models predicted that first instar bertha armyworm larvae might be present in some areas of the prairies. Bertha armyworm larvae could also be developing quickly, thanks to warm weather. The network of pheromone traps across the prairies is reporting low numbers of adults (less than 300 cumulative catch), including in Manitoba (check out the June 21 Manitoba Crop Pest Update) and Alberta. Risk to yield from bertha armyworm increases when cumulative trap catches exceed 300 (300-900 = medium risk, >900 = high risk). For information about scouting, check out the PPMN protocol and the Alberta Agriculture and Irrigation pages.
Diamondback moth
Some areas of the prairies might be at risk of damage from diamondback moth; pheromone traps with cumulative counts greater than 25 male moths so far in 2023 are located around Rosetown and Swift Current in Saskatchewan, in the Vulcan area in Alberta, and in the Central, Eastern, and Interlake regions in Manitoba (see the June 21 Manitoba Crop Pest Update). Like grasshoppers and bertha armyworm, diamond back moth development occurs quickly in warm weather. Last week, we predicted that diamondback moths had reached the second non-migrant generation and we heard of some sightings of larvae in some areas of the prairies. Because diamondback moth can have multiple generations in a single growing season, their populations can build up quickly. Keep scouting for diamondback moth to avoid unpleasant surprises later this summer.
To scout for diamondback moth, estimate the number of diamondback moth larvae per m2 at several locations in a field. The economic threshold for diamondback moth is NOT based on pheromone traps or sweep net samples, but on the density of larvae per plant. For immature and flowering canola, the economic threshold is 100-150 larvae/m2. In podded canola, the economic threshold is 200-300 larvae/m2. See the Field Crop and Forage Pests guide and monitoring protocol for more information about scouting for diamondback moth.
Based on model simulations, bertha armyworm development continues to be 7-10 days ahead of normal. Where present, females should have already begun to lay eggs (Fig. 1).
Figure 1. Proportion (% of total population) of the bertha armyworm (Mamestra configurata) population that is expected to be in the egg stage across the Canadian prairies as of June 18, 2023.
In some areas, first instar larvae (caterpillars) may be present (Fig. 2).
Figure 2. Proportion (% of total population) of the bertha armyworm (Mamestra configurata) population that is expected to be in the larval stage across the Canadian prairies as of June 18, 2023.
This week there have been some reports of large green caterpillars on canola crops in Alberta and Saskatchewan. The green caterpillars are too advanced in their development to be bertha armyworm. These are more likely to be alfalfa looper or clover cutworm. This week, a Canola Watch quiz challenges us to identify ‘green worms‘ in oilseed crops and provides excellent information about how to tell the difference between bertha armyworm, alfalfa looper, diamondback moth, clover cutworm, and cabbageworm.
Based on model simulations, development of overwintered bertha armyworm (Mamestra configurata) continues to be 7-10 days ahead of normal. Where present, we expect the majority of the prairie population of bertha armyworm to now be in the adult stage (Fig. 1) and females have likely already begun to lay eggs (Fig. 2).
Figure 1. Proportion (%) of the bertha armyworm (Mamestra configurata) population that is expected to be in the adult stage across the Canadian prairies as of June 11, 2023.Figure 2. Proportion (%) of the bertha armyworm (Mamestra configurata) population that is expected to be in the egg stage across the Canadian prairies as of June 11, 2023.
Bertha armyworm populations were very low in 2022. So far, trap catches in Alberta in 2023 have also been very low (most traps with less than 20 adult male moths). A few trap locations in Saskatchewan and at least one in Manitoba have reported more than 100 moths caught since the traps were set up in late May or early June.
Pheromone trap monitoring for bertha armyworm provides a regional picture of potential risk. Cumulative trap catches below 300 generally represent low risk. To know if a specific field is at risk of economic yield losses, scouting for larvae in that field is required. The PPMN protocol for bertha armyworm monitoring provides information about scouting for adult and larval bertha armyworm and about economic thresholds for this pest.
Insect scouting and monitoring season is getting into full swing!
Weather patterns in May and so far in June have been perfect for the development of some insect pests, but suboptimal for others. However, it is hard to generalize, as some parts of the prairies have been wet and others dry. Similarly, some areas have been very warm, while others have been cooler. This year it will be very important to scout and to monitor insect populations at the field-scale.
Grasshoppers thrive in warm, dry conditions. This week, some 4th instar nymphs were spotted in ditches in southwestern Saskatchewan, although there are many first, second and some third instar nymphs as well. Signs of damage are starting to appear. Overall grasshopper development continues to be ahead of schedule and two-striped grasshoppers continue to be prevalent.
Diamondback moths that arrived in early May have likely reproduced and adult moths found now could be from the first generation produced on the prairies. Diamondback moths develop rapidly when it is warm and their population densities can build up quickly with each generation. Be ready to scout if pheromone traps in your area have detected diamondback moths this spring.
Bertha armyworm development is also well ahead of schedule – pupal development could be 90% complete in some areas and adult moths could already be flying around. Watch the provincial websites in Alberta, Saskatchewan, and Manitoba for reports on bertha armyworm pheromone trap captures for your area over the next few weeks.
This week, the Insect of the Week featured ground beetles and rove beetles! Both can prey on different life stages of the pea leaf weevil and on other insect pests (and slugs!).
Please read this week’s posts in the Weekly Update for more information about the insects listed above and for a sneak peak of wheat midge development!
Remember, insect Monitoring Protocols containing helpful insect pest biology, how and when to plan for in-field scouting, and economic thresholds to help support in-field management decisions. All are available to read or download for free!
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, full of information and helpful links, can be accessed on our Weekly Update page.
Based on model simulations, development of overwintered bertha armyworm (Mamestra configurata) pupae continues to be significantly ahead of normal for most of the prairies. Bertha armyworm pupae across the prairie region are expected to be at least 90% finished their larval development (Fig. 1); as a result, adults might already be emerging in some areas.
Figure 1. Predicted bertha armyworm (Mamestra configurata) pupal development (%) across the Canadian prairies as of June 4, 2023.
The bertha armyworm model predicts that adults could already be present in a region between Lethbridge, Alberta and Swift Current, Saskatchewan (Fig. 2). Adult moths may also be flying near Edmonton, Alberta and in the northern limits of the Peace River region (Fig. 2).
Figure 2. The proportion of the bertha armyworm (Mamestra configurata) population that is predicted to be in the adult stage (% of total population) across the Canadian prairies as of June 4, 2023.
Based on model simulations, development of overwintered bertha armyworm (Mamestra configurata) pupae is rapidly progressing this spring (Fig. 1).
Figure 1. Predicted bertha armyworm (Mamestra configurata) pupal development (% complete) across the Canadian prairies as of May 28, 2023.
In fact, development is significantly ahead of normal for most of the prairies (Figs. 2). Models suggest that bertha armyworm pupal development in Alberta is 10-14 days faster than average development for this time of year. There are small areas in Alberta where the model predicts that pupal development may be greater than 90% completed.
Figure 2. Long-term average predicted bertha armyworm (Mamestra configurata) pupal development (% completion) across the Canadian prairies as of May 28, 2023. Model runs were conducted with climate normals data.
Where bertha armyworm are present, adults may be appearing in areas where predicted pupal development is greater than 90% complete. We suggest that bertha armyworm traps should be installed as soon as possible. Many thanks to all of the volunteers across the Prairie region who are hosting BAW pheromone traps in 2023!
Weekly Pheromone-baited Trapping Results – Click each province name to access moth reporting numbers observed in Alberta, Saskatchewan and Manitoba(as they become available). Check these sites to assess cumulative counts and relative risk in your geographic region but remember in-field scouting is required to apply the economic threshold to manage both this pest and its natural enemies. For convenience, screen shots of the above maps or data have been placed below for Alberta, Saskatchewan, and Manitoba.
Monitoring:
Larval sampling should commence once the adult moths are noted.
Sample at least three locations, a minimum of 50 m apart.
At each location, mark an area of 1 m2 and beat the plants growing within that area to dislodge the larvae.
Count them and compare the average against the values in the economic threshold table below:
Scouting tips: ● Some bertha armyworm larvae remain green or pale brown throughout their larval life. ● Large larvae may drop off the plants and curl up when disturbed, a defensive behavior typical of cutworms and armyworms. ● Young larvae chew irregular holes in leaves, but normally cause little damage. The fifth and sixth instar stages cause the most damage by defoliation and seed pod consumption. Crop losses due to pod feeding will be most severe if there are few leaves. ● Larvae eat the outer green layer of the stems and pods exposing the white tissue. ● At maturity, in late summer or early fall, larvae burrow into the ground and form pupae.
Refer to the PPMN Bertha armyworm monitoring protocol for help when performing in-field scouting. Use the images below (Fig. 1) to help identify the economically important larvae. Review the 2019 Insect of the Week which featured bertha armyworm and its doppelganger, the clover cutworm!
Figure 1. The egg stage (A), larval stage (B), pupal stage (C), and adult stage (D) of bertha armyworm. Photos: Jonathon Williams (AAFC-Saskatoon).
Biological and monitoring information related to bertha armyworm in field crops is posted by the provinces of Manitoba, Saskatchewan, Alberta and the Prairie Pest Monitoring Network. Also refer to the bertha armyworm pages within the “Field Crop and Forage Pests and their Natural Enemies in Western Canada: Identification and management field guide” which is a free downloadable document as both an English-enhanced or French-enhanced version.
Model simulations for August 3, 2020, indicate that BAW development varies across the prairies. Figures 1 and 2 demonstrate that BAW populations near Winnipeg (Fig. 1) are more advanced than populations near Grande Prairie (Fig. 2). Populations near Winnipeg are predicted to be developing to pupae (Fig. 1). BAW populations near Grande Prairie are expected to be primarily in the larval stage (Fig. 2).
Figure 1. Predicted bertha armyworm (Mamestra configurata) phenology at Winnipeg MB as of August 3, 2020.Figure 2 Predicted bertha armyworm (Mamestra configurata) phenology at Grande Prairie AB as of August 3, 2020.
Weekly Pheromone-baited Trapping Results – Early season detection of bertha armyworm is improved through the use of pheromone-baited unitraps traps deployed in fields across the Canadian prairies. Click each province name to access moth reporting numbers observed in Alberta, Saskatchewan and Manitoba(as they become available). Check these sites to assess cumulative counts and relative risk in your geographic region but remember in-field scouting is required to apply the economic threshold to manage both this pest and its natural enemies. For convenience, screen shots of the above maps or data have been placed below for Alberta, Saskatchewan, and Manitoba.
Monitoring:
Larval sampling should commence once the adult moths are noted.
Sample at least three locations, a minimum of 50 m apart.
At each location, mark an area of 1 m2 and beat the plants growing within that area to dislodge the larvae.
Count them and compare the average against the values in the economic threshold table below:
Scouting tips: ● Some bertha armyworm larvae remain green or pale brown throughout their larval life. ● Large larvae may drop off the plants and curl up when disturbed, a defensive behavior typical of cutworms and armyworms. ● Young larvae chew irregular holes in leaves, but normally cause little damage. The fifth and sixth instar stages cause the most damage by defoliation and seed pod consumption. Crop losses due to pod feeding will be most severe if there are few leaves. ● Larvae eat the outer green layer of the stems and pods exposing the white tissue. ● At maturity, in late summer or early fall, larvae burrow into the ground and form pupae.
Refer to the PPMN Bertha armyworm monitoring protocol for help when performing in-field scouting. Use the images below (Fig. 4) to help identify the economically important larvae. Review the 2019 Insect of the Week which featured bertha armyworm and its doppelganger, the clover cutworm!
Figure 4. The egg stage (A), larval stage (B), pupal stage (C), and adult stage (D) of bertha armyworm. Photos: Jonathon Williams (AAFC-Saskatoon).
Biological and monitoring information related to bertha armyworm in field crops is posted by the provinces of Manitoba, Saskatchewan, Alberta and the Prairie Pest Monitoring Network. Also refer to the bertha armyworm pages within the “Field Crop and Forage Pests and their Natural Enemies in Western Canada: Identification and management field guide” which is a free downloadable document as both an English-enhanced or French-enhanced version.
Click to link to last week’s information posted for Wk 13 (released 23Jul2020) to review the predictive model outputs for this insect pest. As larvae now begin to develop and feed in fields, emphasis is now placed on in-field scouting in areas where high moth counts are being intercepted by provincial networks highlighted below.
Weekly Pheromone-baited Trapping Results– Early season detection of bertha armyworm is improved through the use of pheromone-baited unitraps traps deployed in fields across the Canadian prairies. Click each province name to access moth reporting numbers observed in Alberta, Saskatchewan and Manitoba. Remember in-field scouting is required to apply the economic threshold to manage both this pest and its natural enemies. For convenience, screen shots of available maps or data from Alberta, Saskatchewan, and Manitoba are below.
Refer to the PPMN Bertha armyworm monitoring protocol for help when performing in-field scouting. Use the images above (Fig. 4) to help identify the economically important larvae. Review the 2019 Insect of the Week which featured bertha armyworm and its doppelganger, the clover cutworm!
Figure 4. The egg stage (A), larval stage (B), pupal stage (C), and adult stage (D) of bertha armyworm. Photos: Jonathon Williams (AAFC-Saskatoon).
Biological and monitoring information related to bertha armyworm in field crops is posted by the provinces of Manitoba, Saskatchewan, Alberta and the Prairie Pest Monitoring Network. Also refer to the bertha armyworm pages within the “Field Crop and Forage Pests and their Natural Enemies in Western Canada: Identification and management field guide” which is a free downloadable document as both an English-enhanced or French-enhanced version.
Model simulations for July 19, 2020 (Fig. 1) indicate that 23% of the bertha armyworm (BAW) population is in the egg stage (compared to 35% last week) and 77% are predicted to be larvae (compared to 65% last week). Across the Parkland and Peace River regions, BAW populations are predicted to be primarily in the egg stage (Fig. 1). Other than the Peace River region, populations are primarily in the larval stage (Fig. 1). Fields near Carman, Winnipeg and Morden in Manitoba are expected to have first appearance of pupae, suggesting larval development is advanced (Fig. 1).
Figure 1. Predicted percent of bertha armyworm (Mamestra configurata) population in the larval stageas of July 19, 2020.
The two graphs below demonstrate that BAW populations near Winnipeg (Fig. 2) are more advanced than populations near Grande Prairie (Fig. 3). In Winnipeg populations are primarily in the larval stage with first appearance of pupae (Fig. 2). BAW populations near Grande Prairie are predicted to be in adult, egg and larval stages (Fig. 3).
Figure 2. Predicted bertha armyworm (Mamestra configurata) phenology at Winnipeg MB as of July 19, 2020.Figure 3. Predicted bertha armyworm (Mamestra configurata) phenology at Grande Prairie AB as of July 19, 2020.
Weekly Pheromone-baited Trapping Results – Early season detection of bertha armyworm is improved through the use of pheromone-baited unitraps traps deployed in fields across the Canadian prairies. Click each province name to access moth reporting numbers observed in Alberta, Saskatchewan and Manitoba(as they become available). Check these sites to assess cumulative counts and relative risk in your geographic region but remember in-field scouting is required to apply the economic threshold to manage both this pest and its natural enemies. For convenience, screen shots of the above maps or data have been placed below for Alberta, Saskatchewan, and Manitoba.
Refer to the PPMN Bertha armyworm monitoring protocol for help when performing in-field scouting. Use the images above (Fig. 4) to help identify the economically important larvae. Review the 2019 Insect of the Week which featured bertha armyworm and its doppelganger, the clover cutworm!
Figure 4. The egg stage (A), larval stage (B), pupal stage (C), and adult stage (D) of bertha armyworm. Photos: Jonathon Williams (AAFC-Saskatoon).
Biological and monitoring information related to bertha armyworm in field crops is posted by the provinces of Manitoba, Saskatchewan, Alberta and the Prairie Pest Monitoring Network. Also refer to the bertha armyworm pages within the “Field Crop and Forage Pests and their Natural Enemies in Western Canada: Identification and management field guide” which is a free downloadable document as both an English-enhanced or French-enhanced version.
Model simulations for July 12, 2020 indicate that 35% of the population is in the egg stage (37% last week) and 65% of the population is in the larval stages (14% last week). Across the Parkland and Peace River regions, BAW populations are predicted to be primarily in the egg stage (Fig. 1). Populations across southern regions are primarily in the larval stage (Fig. 1).
Figure 1. Predicted percent of bertha armyworm (Mamestra configurata) population in the larval stageas of July 12, 2020.
The two graphs below demonstrate that larval development near Brandon is predicted to be ahead of fields near Grande Prairie. In Brandon, populations are primarily in the larval stage (Fig. 2) while BAW populations near Grande Prairie are predicted to be predominantly in adult and egg stages (Fig. 3).
Figure 3. Predicted bertha armyworm (Mamestra configurata) phenology at Brandon MB as of July 12, 2020.Figure 3. Predicted bertha armyworm (Mamestra configurata) phenology at Grande Prairie AB as of July 12, 2020.Figure 5. The egg stage (A), larval stage (B), pupal stage (C), and adult stage (D) of bertha armyworm. Photos: Jonathon Williams (AAFC-Saskatoon).
Weekly Pheromone-baited Trapping Results – Early season detection of bertha armyworm is improved through the use of pheromone-baited unitraps traps deployed in fields across the Canadian prairies. Click each province name to access moth reporting numbers observed in Alberta, Saskatchewan and Manitoba(as they become available). Check these sites to assess cumulative counts and relative risk in your geographic region but remember in-field scouting is how the economic threshold is applied to manage this pest.
Refer to the PPMN Bertha armyworm monitoring protocol for help when performing in-field scouting. Use the images above (Fig. 5) to help identify the economically important larvae. Review the 2019 Insect of the Week which featured bertha armyworm and its doppelganger, the clover cutworm!
Biological and monitoring information related to bertha armyworm in field crops is posted by the provinces of Manitoba, Saskatchewan, Alberta and the Prairie Pest Monitoring Network. Also refer to the bertha armyworm pages within the “Field Crop and Forage Pests and their Natural Enemies in Western Canada: Identification and management field guide” which is a free downloadable document as both an English-enhanced or French-enhanced version.
Model simulations for July 5, 2020, indicate that 5 % of the population is in the pupal stage (26 % last week), 43 % is in the adult stage (52 % last week), and 37 % of the population is in the egg stage (20 % last week). In southern Manitoba and southeastern Saskatchewan, larval stages are predicted to increase this week (14 % compared to 2 % last week). Across the Parkland and Peace River regions, BAW populations are predicted to be mostly adults with oviposition occurring in these areas (Fig. 1). Operation of BAW traps in these areas should continue until adult emergence is complete. Populations across southern regions are primarily in the larval stage (Fig. 2).
Figure 1. Predicted percent of bertha armyworm (Mamestra configurata) population in the adult stageas of July 5, 2020.Figure 2. Predicted percent of bertha armyworm (Mamestra configurata) population in the larval stageas of July 5, 2020.
The two graphs demonstrate that larval development near Brandon (Fig. 3) is predicted to be ahead of fields near Lethbridge (Fig. 4).
Figure 3. Predicted bertha armyworm (Mamestra configurata) phenology at Brandon MB as of July 5, 2020.Figure 4. Predicted bertha armyworm (Mamestra configurata) phenology at Lethbridge AB as of July 5, 2020.Figure 5. The egg stage (A), larval stage (B), pupal stage (C), and adult stage (D) of bertha armyworm. Photos: Jonathon Williams (AAFC-Saskatoon).
Weekly Pheromone-baited Trapping Results – Early season detection of bertha armyworm is improved through the use of pheromone-baited unitraps traps deployed in fields across the Canadian prairies. Click each province name to access moth reporting numbers observed in Alberta, Saskatchewan and Manitoba(as they become available). Check these sites to assess cumulative counts and relative risk in your geographic region but remember in-field scouting is how the economic threshold is applied to manage this pest.
Refer to the PPMN Bertha armyworm monitoring protocol for help when performing in-field scouting. Use the images above (Fig. 5) to help identify the economically important larvae. Review the 2019 Insect of the Week which featured bertha armyworm and its doppelganger, the clover cutworm!
Biological and monitoring information related to bertha armyworm in field crops is posted by the provinces of Manitoba, Saskatchewan, Alberta and the Prairie Pest Monitoring Network. Also refer to the bertha armyworm pages within the “Field Crop and Forage Pests and their Natural Enemies in Western Canada: Identification and management field guide” which is a free downloadable document as both an English-enhanced or French-enhanced version.
Bertha armyworm (Lepidoptera: Mamestra configurata) – Important – Watch for updates from your provincial monitoring networks who are compiling cumulative pheromone-baited trap interceptions to assess risk levels in Alberta, Saskatchewan (updated 07Aug2019), and Manitoba (locate table on pg 6). Regions in all three prairie provinces are reporting “uncertain” risk based on pheromone-baited unitrap cumulative counts. SCOUT NOW to confirm in-field larval counts and REMEMBER that LARVAL DENSITIES CAN VARY DRAMATICALLY even between adjacent fields! Scout to protect @FieldHeroes and avoid economic losses! Use the Field Heroes’ scouting guide for bertha armyworm and be sure to read more at their website! Biological and monitoring information related to bertha armyworm in field crops is posted by the provinces of Manitoba, Saskatchewan, Albertaand the Prairie Pest Monitoring Network. Also refer to the bertha armyworm pages within the “Field Crop and Forage Pests and their Natural Enemies in Western Canada: Identification and management field guide” which is a free downloadable document as both an English-enhanced or French-enhanced version.
Refer to the PPMN Bertha armyworm monitoring protocol for help when performing in-field scouting. Use the images below (Fig. 1) to help identify egg masses and the economically important larvae in canola.
Figure 1. Stages of bertha armyworm from egg (A), larva (B), pupa (C) to adult (D).
Photos: J. Williams (Agriculture and Agri-Food Canada).
Now is the time to do in-field scouting for this insect pest. Review the Insect of the Week which features bertha armyworm and its doppelganger, the clover cutworm!
Bertha armyworm (Lepidoptera: Mamestra configurata) – Important – Watch for updates from your local provincial monitoring networks who are compiling cumulative pheromone-baited trap interceptions to assess risk levels in Alberta, Saskatchewan (updated 31Jul2019), and Manitoba (locate table on pg 6). Regions in all three prairie provinces are reporting “uncertain” risk based on pheromone-baited unitrap cumulative counts.
SCOUT NOW to confirm in-field larval counts and REMEMBER that LARVAL DENSITIES CAN VARY DRAMATICALLY even between adjacent fields! Scout to protect @FieldHeroes and avoid economic losses! Use the Field Heroes’ scouting guide for bertha armyworm and be sure to read more at their website!
Biological and monitoring information related to bertha armyworm in field crops is posted by the provinces of Manitoba, Saskatchewan, Alberta and the Prairie Pest Monitoring Network. Also refer to the bertha armyworm pages within the “Field Crop and Forage Pests and their Natural Enemies in Western Canada: Identification and management field guide” which is a free downloadable document as both an English-enhanced or French-enhanced version.
Refer to the PPMN Bertha armyworm monitoring protocol for help when performing in-field scouting. Use the images below (Fig. 1) to help identify egg masses and the economically important larvae in canola.
Figure 1. Stages of bertha armyworm from egg (A), larva (B), pupa (C) to adult (D). Photos: J. Williams (Agriculture and Agri-Food Canada).
Now is the time to do in-field scouting for this insect pest. Review the Insect of the Week which features bertha armyworm and its doppelganger, the clover cutworm!
Bertha armyworm (Lepidoptera: Mamestra configurata) – Predictive model updates are completed for the growing season but can be reviewed here (Wk 14).
Important – Watch for updates from your provincial monitoring networks who are compiling cumulative pheromone-baited trap interceptions to assess risk levels in Alberta, Saskatchewan (updated 24Jul2019), and Manitoba (locate table on pg 6). regions in all three prairie provinces are reporting “uncertain” risk based on pheromone-baited unitrap cumulative counts.
This week – SCOUT NOW to confirm in-field larval counts and REMEMBER that LARVAL DENSITIES CAN VARY DRAMATICALLY even between adjacent fields! Scout to protect @FieldHeroes and avoid economic losses! Use the Field Heroes’ scouting guide for bertha armyworm and be sure to read more at their website!
Biological and monitoring information related to bertha armyworm in field crops is posted by the provinces of Manitoba, Saskatchewan, Alberta and the Prairie Pest Monitoring Network. Also refer to the bertha armyworm pages within the “Field Crop and Forage Pests and their Natural Enemies in Western Canada: Identification and management field guide” which is a free downloadable document as both an English-enhanced or French-enhanced version.
Refer to the PPMN Bertha armyworm monitoring protocol for help when performing in-field scouting. Use the images below (Fig. 1) to help identify egg masses and the economically important larvae in canola.
Figure 1. Stages of bertha armyworm from egg (A), larva (B), pupa (C) to adult (D). Photos: J. Williams (Agriculture and Agri-Food Canada).
Now is the time to do in-field scouting for this insect pest. Review the Insect of the Week which features bertha armyworm and its doppelganger, the clover cutworm!
Bertha armyworm (Lepidoptera: Mamestra configurata) – Predictive model updates are completed for the growing season but can be reviewed here (Wk 14).
Important – Watch for updates from your provincial monitoring networks who are compiling cumulative pheromone-baited trap interceptions to assess risk levels in Alberta, Saskatchewan (updated 10Jul2019), and Manitoba (look on pg 8).
Biological and monitoring information related to bertha armyworm in field crops is posted by the provinces of Manitoba, Saskatchewan, Alberta and the Prairie Pest Monitoring Network. Also refer to the bertha armyworm pages within the “Field Crop and Forage Pests and their Natural Enemies in Western Canada: Identification and management field guide” which is a free downloadable document as both an English-enhanced or French-enhanced version.
Refer to the PPMN Bertha armyworm monitoring protocol for help when performing in-field scouting. Use the images below (Fig. 1) to help identify egg masses and the economically important larvae in canola.
Figure 1. Stages of bertha armyworm from egg (A), larva (B), pupa (C) to adult (D). Photos: J. Williams (Agriculture and Agri-Food Canada).
Now is the time to do in-field scouting for this insect pest. Review the Insect of the Week which features bertha armyworm and its doppelganger, the clover cutworm!
Bertha armyworm (Lepidoptera: Mamestra configurata) – Predictive model updates are completed for the growing season but can be reviewed here (Wk 14).
Important – Watch for updates from your provincial monitoring networks who are compiling cumulative pheromone-baited trap interceptions to assess risk levels in Alberta, Saskatchewan (updated 10Jul2019), and Manitoba (look on pg 7).
Biological and monitoring information related to bertha armyworm in field crops is posted by the provinces of Manitoba, Saskatchewan, Alberta and the Prairie Pest Monitoring Network. Also refer to the bertha armyworm pages within the “Field Crop and Forage Pests and their Natural Enemies in Western Canada: Identification and management field guide” which is a free downloadable document as both an English-enhanced or French-enhanced version.
Refer to the PPMN Bertha armyworm monitoring protocol for help when performing in-field scouting. Use the images below (Fig. 3) to help identify egg masses and the economically important larvae in canola.
Figure 3. Stages of bertha armyworm from egg (A), larva (B), pupa (C) to adult (D). Photos: J. Williams (Agriculture and Agri-Food Canada)
Now is the time to do in-field scouting for this insect pest. Review the Insect of the Week which features bertha armyworm and its doppelganger, the clover cutworm!
Bertha armyworm (Lepidoptera: Mamestra configurata) – Early instar bertha armyworm are predicted to begin appearing across the prairies. A model run for Saskatoon SK indicates that the hatch should be complete (Fig.1) and that BAW should be in the early instar (Fig. 2).
Figure 1. Predicted status of bertha armyworm (Mamestra configurata) populations as of July 8, 2019. Figure 2. Predicted percent of bertha armyworm (Mamestra configurata) populations at LARVAL STAGE across the Canadian prairies as of July 8 2019.
Important – Watch your provincial monitoring networks who are weekly recording cumulative pheromone-baited traps in Alberta, Saskatchewan, and Manitoba (pg 8).
Biological and monitoring information related to bertha armyworm in field crops is posted by the provinces of Manitoba, Saskatchewan, Alberta and the Prairie Pest Monitoring Network. Also refer to the bertha armyworm pages within the “Field Crop and Forage Pests and their Natural Enemies in Western Canada: Identification and management field guide” which is a free downloadable document as both an English-enhanced or French-enhanced version.
Refer to the PPMN Bertha armyworm monitoring protocol for help when performing in-field scouting. Use the images below (Fig. 3) to help identify egg masses and the economically important larvae in canola.
Figure 3. Stages of bertha armyworm from egg (A), larva (B), pupa (C) to adult (D). Photos: J. Williams (Agriculture and Agri-Food Canada)
Now is the time to do in-field scouting for this insect pest. Review the Insect of the Week which features bertha armyworm and its doppelganger, the clover cutworm!
Bertha armyworm (Lepidoptera: Mamestra configurata) – Last week (Fig. 1), bertha armyworm adults were emerging across the prairies and oviposition began across most of the southern prairie regions of SK, AB and MB. That means it’s time to start check the undersides of canola leaves for egg masses and newly hatched larvae!
Figure 1. Predicted precent of bertha armyworm (Mamestra configurata) populations at EGG STAGE across the Canadian prairies as of June 24 2019.
Here’s where bertha armyworm moths were intercepted last year (Fig. 2) so areas previously highlighted in yellow, gold, orange or red should be on the lookout in 2019 for larvae. Also watch your provincial monitoring networks who are weekly recording cumulative pheromone-baited traps in Alberta, Saskatchewan (table on Left of webpage), and Manitoba (pg 7).
Figure 2. Cumulative moth counts from pheromone-baited unitraps deployed during the 2018 growing season.
Biological and monitoring information related to bertha armyworm in field crops is posted by the provinces of Manitoba, Saskatchewan, Alberta and the Prairie Pest Monitoring Network. Also refer to the bertha armyworm pages within the “Field Crop and Forage Pests and their Natural Enemies in Western Canada: Identification and management field guide” which is a free downloadable document as both an English-enhanced or French-enhanced version.
Again, thanks to John Gavloski (Manitoba Agriculture) who helped update the PPMN Bertha armyworm monitoring protocol. Use the images below (Fig. 3) to help identify moths from the by-catch that will be retained in phermone-baited unitraps.
Figure 3. Stages of bertha armyworm from egg (A), larva (B), pupa (C) to adult (D). Photos: J. Williams (Agriculture and Agri-Food Canada)
Also be sure to review the Insect of the Week which features bertha armyworm and its doppelganger, the clover cutworm!
Bertha armyworm (Lepidoptera: Mamestra configurata) – Bertha armyworm adults should be emerging across the prairies and oviposition is predicted to have begun across most of the southern prairie regions of SK, AB and MB (Fig. 1).
Figure 1. Predicted precent of bertha armyworm (Mamestra configurata) populations at EGG STAGE across the Canadian prairies as of June 24 2019.
Biological and monitoring information related to bertha armyworm in field crops is posted by the provinces of Manitoba, Saskatchewan, Alberta and the Prairie Pest Monitoring Network. Also refer to the bertha armyworm pages within the “Field Crop and Forage Pests and their Natural Enemies in Western Canada: Identification and management field guide” which is a free downloadable document as both an English-enhanced or French-enhanced version.
Again, thanks to John Gavloski (Manitoba Agriculture) who helped update the PPMN Bertha armyworm monitoring protocol. Use the images below (Fig. 2) to help identify moths from the by-catch that will be retained in phermone-baited unitraps.
Figure 2. Stages of bertha armyworm from egg (A), larva (B), pupa (C) to adult (D). Photos: J. Williams (Agriculture and Agri-Food Canada)
Also be sure to review the Insect of the Week which features bertha armyworm and its doppelganger, the clover cutworm!
Bertha armyworm (Lepidoptera: Mamestra configurata) – Pupal development is progressing and this week adults should be occurring across most of southern SK and localized areas in AB. Most of the population is predicted to be in the pupal stage (89%). The BAW model indicates that 10% of the population is in the adult stage .
Figure 1. Predicted precent of bertha armyworm (Mamestra configurata) populations at adults stage across the Canadian prairies as of June 17, 2019.
Biological and monitoring information related to bertha armyworm in field crops is posted by the provinces of Manitoba, Saskatchewan, Alberta and the Prairie Pest Monitoring Network. Also refer to the bertha armyworm pages within the “Field Crop and Forage Pests and their Natural Enemies in Western Canada: Identification and management field guide” which is a free downloadable document as both an English-enhanced or French-enhanced version.
Again, thanks to John Gavloski (Manitoba Agriculture) who helped update the PPMN Bertha armyworm monitoring protocol. Use the images below (Fig. 2) to help identify moths from the by-catch that will be retained in phermone-baited unitraps.
Figure 2. Stages of bertha armyworm from egg (A), larva (B), pupa (C) to adult (D). Photos: J. Williams (Agriculture and Agri-Food Canada)
Also be sure to review the Insect of the Week which features bertha armyworm and its doppelganger, the clover cutworm!
Bertha armyworm (Lepidoptera: Mamestra configurata) – Based on BAW model runs, this week pupal development is greater than 80% across most of southern and central areas of the prairies (Fig. 1). Within the next five days BAW adults should begin to emerge in these areas.
Figure 1. Predicted bertha armyworm (Mamestra configurata) pupal development across the Canadian prairies as of June 11, 2019.
Please ensure pheromone traps are out in SK and AB fields this week!
Table 1. Predicted emergence date of bertha armyworm moths at select locations across the Canadian prairies in 2019.
A special thanks to John Gavloski (Manitoba Agriculture) who helped update the PPMN Bertha armyworm monitoring protocol. Use the images below (Fig. 2) to help identify moths from the by-catch that will be retained in phermone-baited unitraps.
Figure 2. Stages of bertha armyworm from egg (A), larva (B), pupa (C) to adult (D). Photos: J. Williams (Agriculture and Agri-Food Canada)
Also be sure to review the Insect of the Week which features bertha armyworm and its doppelganger, the clover cutworm!
The case of the bertha armyworm and the clover cutworm (and other cutworm species)
Clover cutworm larva cc-by 3.0 Lo Troisfontaine
Bertha armyworm – caterpillar Mike Dolinski, MikeDolinski@hotmail.com
Are those bertha armyworms (Mamestra configurata) eating your canola, mustard or alfalfa (also found on lamb’s-quarters, peas, flax, potato)? Or is it maybe a clover cutworm (Discestra trifolii)? [Note: not all cutworm species spend their larval stage underground.] The larvae of the two species are doppelgangers as they are similar in appearance, have a large overlap in host crops, and have similar timing (June-September). Telling them apart can be a challenge but here are few tips to focus on to help distinguish:
Colour:
there are generally fewer velvety black clover cutworm caterpillars, with most of the clover cutworm larvae being green or pale brown
Lateral stripe:
On the clover cutworm it is yellowish-pink
On the bertha armyworm it is yellowish-orange
Climbing cutworm larva – from Cutworm Field Guide Climbing cutworm adults – from Cutworm Field Guide
In terms of scouting, economic thresholds and control options, treat both species as you would bertha armyworms.
Bertha armyworm – adult Alberta Agriculture and Rural Development Clover cutworm adult cc-by-nc-sa 2.0 Ilona Loser
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.
Bertha armyworm (Lepidoptera: Mamestra configurata) – Pupal development is approximately 40%. Average development is 48% (Fig. 1).
Figure 1. Predicted bertha armyworm (Mamestra configurata) pupal development acrossthe Canadian prairies as of May 28, 2019.
In order to determine when adults may emerge, the BAW model was run for Brandon MB (Fig. 2), Saskatoon SK (Fig. 3), Lethbridge AB (Fig. 4) and Edmonton AB (Fig. 5) and projected to June 30, 2019. Model projections indicate that adults will begin to emerge in mid June. Recent heat will advance development of pupae. Traps should be placed in fields when pupal development reaches 80%. Based on model projections, it is advisable that traps be placed in fields on or before June 7.
Figure 2. Predicted development of bertha armyworm populations near Brandon MB projected to June 30, 2019. Figure 3. Predicted development of bertha armyworm populations near Saskatoon SK projected to June 30, 2019. Figure 4. Predicted development of bertha armyworm populations near Lethbridge AB projected to June 30, 2019. Figure 5. Predicted development of bertha armyworm populations near Edmonton AB projected to June 30, 2019.
Economically significant insect pests are monitored across the Canadian prairies each year, thanks to extensive networks of collaborators and cooperators. In 2018, that effort culminated in 5764 survey stops across Manitoba, Saskatchewan, Alberta and the BC Peace!
Here’s what’s included in the PDF file:
Average tempature, average precipitation, and modeled soil moisture for 2018.
A series of geospatial maps are included for each of the target species; the current map is followed by the previous 4 years.
For some species, the geospatial maps represent 2018 distributions used to infer risk in the coming 2019 growing season. Data is included for bertha armyworm, cabbage seedpod weevil, pea leaf weevil, wheat stem sawfly and diamondback moth.
For wheat midge and grasshoppers, the geospatial maps forecast or predict expected populations or risk for the 2019 growing season.
These maps help the agricultural industry prepare to manage insect pests across the prairies and helps growers make crop choices and anticipate scouting priorities within their growing region. From May to July, the Weekly Updates will provide in-season updates, predictive model outputs plus scouting tips and links to relevant information.
Thank you to the many people who monitor each growing season!
Bertha armyworm (Lepidoptera: Mamestra configurata) – Pheromone trapping across the prairies is almost complete for the 2018 growing season but now it is important to scout for larvae feeding on leaves and developing pods!
Review your province’s 2018 bertha armyworm pheromone trapping results towards the end of this Post.
Monitoring:
Larval sampling should commence once the adult moths are noted.
Sample at least three locations, a minimum of 50 m apart.
At each location, mark an area of 1 m2 and beat the plants growing within that area to dislodge the larvae.
Count them and compare the average against the values in the economic threshold table below:
Scouting tips:
Some bertha armyworm larvae remain green or pale brown throughout their larval life.
Large larvae may drop off the plants and curl up when disturbed, a defensive behavior typical of cutworms and armyworms.
Young larvae chew irregular holes in leaves, but normally cause little damage. The fifth and sixth instar stages cause the most damage by defoliation and seed pod consumption. Crop losses due to pod feeding will be most severe if there are few leaves.
Larvae eat the outer green layer of the stems and pods exposing the white tissue.
At maturity, in late summer or early fall, larvae burrow into the ground and form pupae.
Albertans can access the online reporting map (screenshot below retrieved 14Aug2018 for reference):
Saskatchewan growers can check the 2018 bertha armyworm map (screenshot below retrieved 01Aug2018 for reference):
Manitoban growers can find bertha armyworm updates in that province’s Insect and Disease Updates. A screen shot of that summary (retrieved 01Aug2018) is pasted below:
Bertha armyworm (Lepidoptera: Mamestra configurata) – Pheromone trapping across the prairies is almost complete for the 2018 growing season but now it is important to scout for larvae feeding on leaves and developing pods!
Review your province’s 2018 bertha armyworm pheromone trapping results towards the end of this Post.
Monitoring:
Larval sampling should commence once the adult moths are noted.
Sample at least three locations, a minimum of 50 m apart.
At each location, mark an area of 1 m2 and beat the plants growing within that area to dislodge the larvae.
Count them and compare the average against the values in the economic threshold table below:
Scouting tips:
Some bertha armyworm larvae remain green or pale brown throughout their larval life.
Large larvae may drop off the plants and curl up when disturbed, a defensive behavior typical of cutworms and armyworms.
Young larvae chew irregular holes in leaves, but normally cause little damage. The fifth and sixth instar stages cause the most damage by defoliation and seed pod consumption. Crop losses due to pod feeding will be most severe if there are few leaves.
Larvae eat the outer green layer of the stems and pods exposing the white tissue.
At maturity, in late summer or early fall, larvae burrow into the ground and form pupae.
Albertans can access the online reporting map (screenshot below retrieved 31Jul2018 for reference):
Saskatchewan growers can check the 2018 bertha armyworm map (screenshot below retrieved 31Jul2018 for reference):
Manitoban growers can find bertha armyworm updates in that province’s Insect and Disease Updates. A screen shot of that summary is pasted below:
Bertha armyworm (Lepidoptera: Mamestra configurata) – Pheromone trapping across the prairies is almost complete for the 2018 growing season but now it is important to scout for larvae feeding on leaves and developing pods.
Monitoring:
Larval sampling should commence once the adult moths are noted.
Sample at least three locations, a minimum of 50 m apart.
At each location, mark an area of 1 m2 and beat the plants growing within that area to dislodge the larvae.
Count them and compare the average against the values in the economic threshold table below:
Scouting tips:
Some bertha armyworm larvae remain green or pale brown throughout their larval life.
Large larvae may drop off the plants and curl up when disturbed, a defensive behavior typical of cutworms and armyworms.
Young larvae chew irregular holes in leaves, but normally cause little damage. The fifth and sixth instar stages cause the most damage by defoliation and seed pod consumption. Crop losses due to pod feeding will be most severe if there are few leaves.
Larvae eat the outer green layer of the stems and pods exposing the white tissue.
At maturity, in late summer or early fall, larvae burrow into the ground and form pupae.
Albertans can access the online reporting map (screenshot below retrieved 24Jul2018 for reference):
Saskatchewan growers can check the 2018 bertha armyworm map (screenshot below retrieved 26Jul2018 for reference):
Manitoban growers can find bertha armyworm updates in that province’s Insect and Disease Updates. The July 25th update summarized that, “out of the 99 traps, 87 currently have cumulative counts in the low risk category (less than 300), one trap is in the moderate risk range, and 11 traps are in the uncertain risk category. Most of the highest cumulative counts so far are in the western part of Manitoba.”
Bertha armyworm (Lepidoptera: Mamestra configurata) – Pheromone trapping across the prairies is almost complete for the 2018 growing season but now it is important to scout for larvae feeding on leaves.
Monitoring:
Larval sampling should commence once the adult moths are noted.
Sample at least three locations, a minimum of 50 m apart.
At each location, mark an area of 1 m2 and beat the plants growing within that area to dislodge the larvae.
Count them and compare the average against the values in the economic threshold table below:
Scouting tips:
Some bertha armyworm larvae remain green or pale brown throughout their larval life.
Large larvae may drop off the plants and curl up when disturbed, a defensive behavior typical of cutworms and armyworms.
Young larvae chew irregular holes in leaves, but normally cause little damage. The fifth and sixth instar stages cause the most damage by defoliation and seed pod consumption. Crop losses due to pod feeding will be most severe if there are few leaves.
Larvae eat the outer green layer of the stems and pods exposing the white tissue.
At maturity, in late summer or early fall, larvae burrow into the ground and form pupae.
Albertans can access the online reporting map (screenshot below retrieved 18Jul2018 for reference):
Saskatchewan growers can check the 2018 bertha armyworm map (screenshot below retrieved 18Jul2018 for reference):
Manitoban growers can find bertha armyworm updates in that province’s Insect and Disease Updates. The July 11th update summarized that, “out of the 99 traps, 93 currently have cumulative counts in the low risk category (less than 300), and six traps are in the uncertain risk category. Most of the highest cumulative counts so far are in the western part of Manitoba. Trap counts in eastern Manitoba and the Interlake have generally been quite low.”
Bertha armyworm (Lepidoptera: Mamestra configurata) – BAW populations are predicted to be in the larval stages and may have begun feeding within the plant canopy on leaves. Figure 1 illustrates that BAW oviposition is complete and that the population is in the larval stage for populations near Brandon (Fig. 1).
Figure 1. Predicted BAW phenoloyg at Brandon MB. Values are based on model simulations for April 1-July 2, 2018 (projected to July 10, 2018)
Many thanks to those who are checking a bertha armyworm pheromone trap on a weekly basis. Please use the reference photo below kindly shared by Saskatchewan Agriculture to aid your identification and reporting of trap interceptions. Note the kidney-bean white-patterned shape on each forewing but also know other cutworm species can resemble bertha armyworm moths. Check carefully and thanks for your help!
Monitoring:
Larval sampling should commence once the adult moths are noted.
Sample at least three locations, a minimum of 50 m apart.
At each location, mark an area of 1 m2 and beat the plants growing within that area to dislodge the larvae.
Count them and compare the average against the values in the economic threshold table below:
Scouting tips:
Some bertha armyworm larvae remain green or pale brown throughout their larval life.
Large larvae may drop off the plants and curl up when disturbed, a defensive behavior typical of cutworms and armyworms.
Young larvae chew irregular holes in leaves, but normally cause little damage. The fifth and sixth instar stages cause the most damage by defoliation and seed pod consumption. Crop losses due to pod feeding will be most severe if there are few leaves.
Larvae eat the outer green layer of the stems and pods exposing the white tissue.
At maturity, in late summer or early fall, larvae burrow into the ground and form pupae.
Keep track of the Provincial Entomologist Updates for the latest in-season pheromone trap monitoring results for 2018.
Saskatchewanians can view the latest pheromone trap interceptions below kindly provided by Saskatchewan Agriculture.
Albertans can access the online reporting map (screenshot retrieved 04Jul018 provided below for reference:
Bertha armyworm (Lepidoptera: Mamestra configurata) – As of June 24, 2018, BAW development continues to be 7-10 days ahead of normal development (Figs. 3 A and B). Pupal development is complete across the prairies (Fig. 1).
Near Saskatoon SK, BAW egg hatch is nearly complete and larvae are present (Fig. 2). Based on Long Term Climate Normal (LTCN) data, larvae generally begin to occur the last few days of June (Fig. 3).
Figure 2. Predicted BAW phenology at Saskatoon SK. Values are based on model simulations for April 1 – June 24, 2018 and B) Long term climate normals.Figure 3. Predicted BAW phenology at Saskatoon SK. Values are based on model simulations for Long Term Climate Normals (LTCN).
Many thanks to those who are checking a bertha armyworm pheromone trap on a weekly basis. Please use the reference photo below kindly shared by Saskatchewan Agriculture to aid your identification and reporting of trap interceptions. Note the kidney-bean white-patterned shape on each forewing but also know other cutworm species can resemble bertha armyworm moths. Check carefully and thanks for your help!
Monitoring:
Larval sampling should commence once the adult moths are noted.
Sample at least three locations, a minimum of 50 m apart.
At each location, mark an area of 1 m2 and beat the plants growing within that area to dislodge the larvae.
Count them and compare the average against the values in the economic threshold table below:
Scouting tips:
Some bertha armyworm larvae remain green or pale brown throughout their larval life.
Large larvae may drop off the plants and curl up when disturbed, a defensive behavior typical of cutworms and armyworms.
Young larvae chew irregular holes in leaves, but normally cause little damage. The fifth and sixth instar stages cause the most damage by defoliation and seed pod consumption. Crop losses due to pod feeding will be most severe if there are few leaves.
Larvae eat the outer green layer of the stems and pods exposing the white tissue.
At maturity, in late summer or early fall, larvae burrow into the ground and form pupae.
Keep track of the Provincial Entomologist Updates for the latest in-season pheromone trap monitoring results for 2018.
Albertans can access the online reporting map (screenshot retrieved 28Jun2018 provided below for reference:
Bertha armyworm (Lepidoptera: Mamestra configurata) – BAW development continues to be 7-10 days ahead of normal development (Figs. 1 and 2). Near Saskatoon, oviposition is predicted to be well underway (Fig. 1).
Figure 1. Predicted bertha armyworm phenology at Saskatoon SK. Values are based on model simulations for April 1 – June 18, 2018.
Based on climate data (LTCN), oviposition near Saskatoon should begin the third week of June (Fig. 2).
Figure 2. Predicted bertha armyworm phenology at Saskatoon SK when using Long Term Climate Normal (LTCN) data.
Many thanks to those who are checking a bertha armyworm pheromone trap on a weekly basis. Please use the reference photo below kindly shared by Saskatchewan Agriculture to aid your identification and reporting of trap interceptions. Note the kidney-bean white-patterned shape on each forewing but also know other cutworm species can resemble bertha armyworm moths. Check carefully and thanks for your help!
Monitoring:
Larval sampling should commence once the adult moths are noted.
Sample at least three locations, a minimum of 50 m apart.
At each location, mark an area of 1 m2 and beat the plants growing within that area to dislodge the larvae.
Count them and compare the average against the values in the economic threshold table below:
Scouting tips:
Some bertha armyworm larvae remain green or pale brown throughout their larval life.
Large larvae may drop off the plants and curl up when disturbed, a defensive behavior typical of cutworms and armyworms.
Young larvae chew irregular holes in leaves, but normally cause little damage. The fifth and sixth instar stages cause the most damage by defoliation and seed pod consumption. Crop losses due to pod feeding will be most severe if there are few leaves.
Larvae eat the outer green layer of the stems and pods exposing the white tissue.
At maturity, in late summer or early fall, larvae burrow into the ground and form pupae.
Keep track of the Provincial Entomologist Updates for the latest in-season pheromone trap monitoring results for 2018.
Albertans can access the online reporting map (screenshot retrieved 19Jun2018 provided below for reference:
Bertha armyworm (Lepidoptera: Mamestra configurata) – BAW development continues to be 7-10 days ahead of normal development (Fig. 1).
Figure 1. Percentage of pupal stage heat requirements for emergence of bertha armyworm (as of June 20, 2018).
Near Saskatoon SK, adult emergence is well underway and oviposition is predicted to have begun this week. Based on climate data, oviposition near Saskatoon should begin around the third week of June.
Reminder –Table 1. Projected dates for BAW adult emergence for June 4, 2018 (projected to June 30, 2018).
For those who are now checking a bertha armyworm pheromone trap on a weekly basis, we provide an excellent photo kindly shared by Saskatchewan Agriculture to aid your identification and reporting of trap interceptions. Note the kidney-bean white-patterned shape on each forewing but also know other cutworm species can resemble bertha armyworm moths so check carefully and thanks for your help!
Bertha armyworm (Lepidoptera: Mamestra configurata) – The BAW model is predicting that pupae are developing rapidly in the soil and that development is well ahead of average (Fig. 1). Development is expected to be 5 – 6 days faster than average.
Though cooler temperatures have slowed BAW development, moths are predicted to emerge 10 days ahead of average (Table 1). Pupal development is approximately 82% (Fig. 1). Model output predicts that emergence may begin as early as June 9th.
Table 1. Projected dates for BAW adult emergence for June 4, 2018 (projected to June 30, 2018).
Figure 1. Predicted bertha armyworm pupal development (as of June 3, 2018).
Updated phenology models for insect pests on the Canadian prairies will be posted to our new Predictive Model Update page during the growing season, as they become available. This information is intended to supplement the Weekly Updates while providing the most current information to further support in-field scouting.
Whenever items are posted to this page, @vanbugsky will be Tweeting and using #PPMNblog to help users access this most up-to-date information.
This week, an updated table of predicted emergence dates for bertha armyworm was posted for across the Canadian prairies (May 30, 2018). Those in charge of coordinating deployment of pheromone traps will need to pay particular attention to these dates.
Bertha armyworm (Lepidoptera: Mamestra configurata) – The BAW model is predicting that pupae are developing rapidly in the soil and that development is well ahead of average (Fig. 1). Development is expected to be 5 – 6 days faster than average.
Figure 1. Predicted bertha armyworm pupal development (as of May 30, 2018).
Pupal development is approximately 72% (long term average is 47%). Model output predicts that emergence may begin as early as June 6, 2018 (Table 1).
Table 1. Projected dates for bertha armyworm adult emergence as of May 28, 2018 and projecting to June 30, 2018.
Reminder – Review the 2017 bertha armyworm distribution map for the Canadian prairies which reports cumulative pheromone trap counts intercepting male moths during the 2017 growing season.
Bertha armyworm (Lepidoptera: Mamestra configurata) – Bertha armyworm (BAW) – BAW pupae, developing in the soil, are predicted to be ahead of average development. Pupal development is predicted at approximately 50% (Fig. 1) whereas the long term average is 36%.
Figure 1. Predicted bertha armyworm pupal development across the prairies as of May 21, 2018.
Model output predicts that emergence may begin as early as June 9th for the Regina area. Development is expected to be 5-6 days faster than average (Fig. 2; Table 1).
Figure 2. Predicted bertha armyworm phenology at Regina SK. Values are based on
model simulations, for April 1 – May 21, 2018 (projected to June 30, 2018).
Table 1. Projected dates for bertha armyworm adult emergence.
Reminder – Review the 2017 bertha armyworm distribution map for the Canadian prairies which reports cumulative pheromone trap counts intercepting male moths during the 2017 growing season.
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.
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.
Bertha armyworm (Lepidoptera: Mamestra configurata) – REMINDER – Reporting sites across the prairies have generally reported lower cumulative interceptions and cumulative counts are summarized by provincial staff in Manitoba, SaskatchewanandAlberta.
Scouting tips: ● Some bertha armyworm larvae remain green or pale brown throughout their larval life. ● Large larvae may drop off the plants and curl up when disturbed, a defensive behavior typical of cutworms and armyworms. ● Young larvae chew irregular holes in leaves, but normally cause little damage. The fifth and sixth instar stages cause the most damage by defoliation and seed pod consumption. Crop losses due to pod feeding will be most severe if there are few leaves. ● Larvae eat the outer green layer of the stems and pods exposing the white tissue. ● At maturity, in late summer or early fall, larvae burrow into the ground and form pupae. Monitoring: – Larval sampling should commence once the adult moths are noted. – Sample at least three locations, a minimum of 50 m apart. – At each location, mark an area of 1 m2 and beat the plants growing within that area to dislodge the larvae. – Count them and compare the average against the values in the economic threshold table below:
Bertha armyworm (Lepidoptera: Mamestra configurata) – REMINDER – Reporting sites across the prairies have generally reported lower cumulative interceptions and cumulative counts are summarized by provincial staff in Manitoba, SaskatchewanandAlberta. Manitoba counts as of July 26, 2017
In-field monitoring for egg masses and newly emerged larvae (photo below) should initially focus on the undersides of leaves plus watch the margins of leaves for feeding. Bertha armyworm larvae will also feed on newly developing pods so the whole plant should be examined. Watch for the following life stages:
Scouting tips: ● Some bertha armyworm larvae remain green or pale brown throughout their larval life. ● Large larvae may drop off the plants and curl up when disturbed, a defensive behavior typical of cutworms and armyworms. ● Young larvae chew irregular holes in leaves, but normally cause little damage. The fifth and sixth instar stages cause the most damage by defoliation and seed pod consumption. Crop losses due to pod feeding will be most severe if there are few leaves. ● Larvae eat the outer green layer of the stems and pods exposing the white tissue. ● At maturity, in late summer or early fall, larvae burrow into the ground and form pupae. Monitoring: – Larval sampling should commence once the adult moths are noted. – Sample at least three locations, a minimum of 50 m apart. – At each location, mark an area of 1 m2 and beat the plants growing within that area to dislodge the larvae. – Count them and compare the average against the values in the economic threshold table below:
Bertha armyworm (Lepidoptera: Mamestra configurata) – Reporting sites across the prairies have generally reported lower cumulative interceptions and cumulative counts are summarized by provincial staff in Manitoba, SaskatchewanandAlberta. Manitoba counts as of July 26, 2017
In-field monitoring for egg masses and newly emerged larvae (photo below) should initially focus on the undersides of leaves plus watch the margins of leaves for feeding. Bertha armyworm larvae will also feed on newly developing pods so the whole plant should be examined. Watch for the following life stages:
Scouting tips: ● Some bertha armyworm larvae remain green or pale brown throughout their larval life. ● Large larvae may drop off the plants and curl up when disturbed, a defensive behavior typical of cutworms and armyworms. ● Young larvae chew irregular holes in leaves, but normally cause little damage. The fifth and sixth instar stages cause the most damage by defoliation and seed pod consumption. Crop losses due to pod feeding will be most severe if there are few leaves. ● Larvae eat the outer green layer of the stems and pods exposing the white tissue. ● At maturity, in late summer or early fall, larvae burrow into the ground and form pupae. Monitoring: – Larval sampling should commence once the adult moths are noted. – Sample at least three locations, a minimum of 50 m apart. – At each location, mark an area of 1 m2 and beat the plants growing within that area to dislodge the larvae. – Count them and compare the average against the values in the economic threshold table below:
Bertha armyworm (Lepidoptera: Mamestra configurata) – Bertha armyworm should be in the adult stage across the prairies this week. The map illustrates predicted appearance of adults (percent of the population) across the southern prairies.
For those monitoring BAW pheromone traps, compare trap “catches” to the following reference photo kindly shared by Saskatchewan Agriculture:
Bertha armyworm (Lepidoptera: Mamestra configurata) – Bertha armyworm should be in the adult stage across the prairies this week. The map illustrates predicted appearance of adults (percent of the population) across the southern prairies.
For those monitoring BAW pheromone traps, compare trap “catches” to the following reference photo kindly shared by Saskatchewan Agriculture:
Bertha armyworm (Lepidoptera: Mamestra configurata) – Bertha armyworm should be in the adult stage across the prairies this week. The map illustrates predicted appearance of adults (percent of the population) across the southern prairies.
For those monitoring BAW pheromone traps, compare trap “catches” to the following reference photo kindly shared by Saskatchewan Agriculture:
Bertha armyworm (Lepidoptera: Mamestra configurata) – Bertha armyworm should be in the adult stage across the prairies this week. The map illustrates predicted appearance of adults (percent of the population) across the southern prairies.
For those monitoring BAW pheromone traps, compare trap “catches” to the following reference photo kindly shared by Saskatchewan Agriculture:
Bertha armyworm (Lepidoptera: Mamestra configurata) – Emergence of adult moths is well underway. The map illustrates predicted appearance of adults (percent of the population) across the southern prairies; oviposition is predicted to begin this week with first hatch beginning later next week.
For those of you monitoring BAW pheromone traps, you may want to compare trap “catches” to the following reference photo kindly shared by Saskatchewan Agriculture:
Bertha armyworm (Lepidoptera: Mamestra configurata) – Warm conditions over the past week has advanced pupal development across the southern prairies. Compared to last week, adult emergence is predicted to be 1-7 days earlier. The first map shows that pupal development is well underway across southern and central regions. Average development was 70% (50% last week). Pupal development at a number of locations was 75%.
The second map indicates that development, compared to long-term-average, is slightly greater than average development. Model output indicted that first adult emergence may occur this week in the Vauxhall, Brooks and Regina areas.
IMPORTANT – The table indicates predicted dates of first appearance of adults for specific locations across the prairies. Adult emergence generally occurs within 5-7 days after 80% development.
Reminder – The video below posted by Alberta Agriculture and Forestry’s Scott Meers describes how pheromone traps are used to monitor this important pest of canola.
Those monitoring BAW pheromone traps may want to compare trap “catches” to the following reference photo kindly shared by Saskatchewan Agriculture below:
Bertha armyworm (Lepidoptera: Mamestra configurata) – As of May 28th, predicted pupal development is well underway. We are fortunate to have two methods projecting pupal development: –> Figure 1 reflects pupal development BASED ON DEGREE DAYS ONLY. –> Figure 2 reflects pupal development BASED ON CLIMEX MODELLING (i.e., incorporates environmental data + biological data for organisms) AND legend is designed to estimate WHEN PHEROMONE TRAPS SHOULD BE DEPLOYED (i.e., pheromone traps are best deployed at ~80% pupal development).
Figure 1. Predicted stage of pupal development of overwintered Bertha armyworm (based on Degree-Day heat units) set to emerge in 2017.
FIGURE 2. Predicted pupal development of Bertha armyworm (based on Climex model and legend designed to reflect that pheromone traps are best deployed at ~80% pupal development).
More specifically, Figure 2 shows the average pupal development is 50% (36% last week), and as high as 75% at a number of locations. The three graphs below show that adult emergence is predicted to be six days sooner in the Winnipeg region than in fields near Vegreville and ten days sooner than the Yorkton area.
IMPORTANT – The table indicates predicted dates of first appearance of adults for specific locations across the prairies. We generally suggest that traps go out when pupal development is at 80%. Adult emergence generally occurs within 5-7 days after 80% development. As of May 29, 2017, there is a large area in southern Alberta that is greater than 70%.
Reminder – These maps will be updated weekly to aid those who deploy and monitor this moth using pheromone traps. The video below posted by Alberta Agriculture and Forestry’s Scott Meers describes how pheromone traps are used to monitor this important pest of canola.
Bertha armyworm (Lepidoptera: Mamestra configurata) – This week, predicted pupal development is well underway. Average development is 36% (27% last week); average development is 37% (Fig. 1).
Figure 1. Predicted stage of pupal development of overwintered Bertha armyworm set to emerge in 2017.
Reminder – These maps will be updated weekly to aid those who deploy and monitor this moth using pheromone traps. The video below posted by Alberta Agriculture and Forestry’s Scott Meers describes how pheromone traps are used to monitor this important pest of canola.
Bertha armyworm (Lepidoptera: Mamestra configurata) – The first map (Fig. 1) shows that predicted pupal development is well underway (average 27%).
Figure 1. Predicted stage of pupal development of overwintered Bertha armyworm set to emerge in 2017.
The second map (Fig. 2) indicates that predicted development this year is ahead of long term averages in Manitoba and Saskatchewan.
Figure 2. Pupal development of overwintered Bertha armyworm in 2017 compared to long-term averages observed across the Canadian prairies.
These maps will be updated weekly to aid those who deploy and monitor this moth using pheromone traps. The video below posted by Alberta Agriculture and Forestry’s Scott Meers describes how pheromone traps are used to monitor this important pest of canola.
The 2017 Prairie-Wide Risk and Forecast Maps can be viewed and downloaded here. Maps are generated for bertha armyworm, grasshoppers, wheat midge, cabbage seedpod weevil, pea leaf weevil, wheat stem sawfly, diamondback moth as well as average temperature, average precipitation, and modeled soil moisture for the Canadian prairies.
Thank you to the many people who monitor each growing season! An astonishing 6414 survey stops were involved in the insect monitoring performed across the Canadian prairies in 2016!
Manitoba growers can access general information on pest and beneficial insects from a series of fact sheets posted at theInsect section of their website.
More information related to the above maps and insects can be obtained by contacting Manitoba Agriculture entomologist John Gavloski.
All the Saskatchewan Insect Survey and Forecast Maps and more can be found on Saskatchewan.ca ! To view all our agriculture maps check out our Maps for Farmers and Agribusiness section.
Alberta has posted their forecast and survey maps for several insect pest species occurring in field crops. Visit their home page to view all the Alberta maps.
The following list and hyperlinks were provided by Shelley Barkley via the Alberta Insect Pest Monitoring Network.
Scott Meers, entomologist with Alberta Agriculture and Forestry, was interviewed and spoke about Alberta insect forecasts for 2017. That series of five interviews can be access with the following hyperlinks:
Additionally, Alberta Agriculture and Forestry has updated their webpages with the following:
They have created a graphic that illustrates the “range expansion” of 2 evil weevils in Alberta: pea leaf and cabbage seedpod.
Similar graphics have been added to their bertha armyworm page. Check out the past “six years of bertha armyworm moth” in Alberta which can be accessed via an hyperlink positioned on their bertha armyworm web page.
Their grasshopper page has been updated too – check out the “historic grasshopper maps” for Alberta via a hyperlinklocated on their grasshopper web page.
The past “eight years of sawfly” in Alberta can be accessed via a hyperlink located on their wheat stem sawfly web page.
Bertha armyworm (Lepidoptera: Mamestra configurata) – Reminder – Reporting sites across the prairies have generally reported lower cumulative interceptions but moderate numbers have been intercepted a few sites within Manitoba and Saskatchewan.
Cumulative counts from pheromone traps are summarized and mapped by provincial staff in Manitoba, SaskatchewanandAlberta. Screen shots of the three maps are provided below: Manitoba map (screenshot retrieved August 3, 2016):
Saskatchewan map (screenshot retrieved August 3, 2016):
Alberta map (screenshot retrieved August 3, 2016):
Reminder – In-field monitoring for egg masses and newly emerged larvae (photo below) should initially focus on the undersides of leaves plus watch the margins of leaves for feeding. Bertha armyworm larvae will also feed on newly developing pods so the whole plant should be examined. Watch for the following life stages:
Scouting tips: ● Some bertha armyworm larvae remain green or pale brown throughout their larval life. ● Large larvae may drop off the plants and curl up when disturbed, a defensive behavior typical of cutworms and armyworms. ● Young larvae chew irregular holes in leaves, but normally cause little damage. The fifth and sixth instar stages cause the most damage by defoliation and seed pod consumption. Crop losses due to pod feeding will be most severe if there are few leaves. ● Larvae eat the outer green layer of the stems and pods exposing the white tissue. ● At maturity, in late summer or early fall, larvae burrow into the ground and form pupae. Monitoring: – Larval sampling should commence once the adult moths are noted. – Sample at least three locations, a minimum of 50 m apart. – At each location, mark an area of 1 m2 and beat the plants growing within that area to dislodge the larvae. – Count them and compare the average against the values in the economic threshold table below:
Bertha armyworm (Lepidoptera: Mamestra configurata) – Reporting sites across the prairies have generally reported lower cumulative interceptions but moderate numbers have been intercepted a few sites within Manitoba and Saskatchewan. Cumulative counts from pheromone traps are summarized and mapped by provincial staff in Manitoba, SaskatchewanandAlberta. Screen shots of the three maps are provided below:
Manitoba map (screenshot retrieved July 27, 2016):
Saskatchewan map (screenshot retrieved July 13, 2016):
Alberta map (screenshot retrieved July 27, 2016):
Reminder – In-field monitoring for egg masses and newly emerged larvae (photo below) should initially focus on the undersides of leaves plus watch the margins of leaves for feeding. Bertha armyworm larvae will also feed on newly developing pods so the whole plant should be examined. Watch for the following life stages:
Scouting tips: ● Some bertha armyworm larvae remain green or pale brown throughout their larval life. ● Large larvae may drop off the plants and curl up when disturbed, a defensive behavior typical of cutworms and armyworms. ● Young larvae chew irregular holes in leaves, but normally cause little damage. The fifth and sixth instars cause the most damage by defoliation and seed pod consumption. Crop losses due to pod feeding will be most severe if there are few leaves. ● Larvae eat the outer green layer of the stems and pods exposing the white tissue. ● At maturity, in late summer or early fall, larvae burrow into the ground and form pupae. Monitoring: – Larval sampling should commence once the adult moths are noted. – Sample at least three locations, a minimum of 50 m apart. – At each location, mark an area of 1 m2 and beat the plants growing within that area to dislodge the larvae. – Count them and compare the average against the values in the economic threshold table below:
Bertha armyworm (Lepidoptera: Mamestra configurata) – Reporting sites across the prairies have generally reported lower cumulative interceptions and cumulative counts are summarized by provincial staff in Manitoba, SaskatchewanandAlberta.
Saskatchewan map as of July 13, 2016
Alberta map as of July 20, 2016
In-field monitoring for egg masses and newly emerged larvae (photo below) should initially focus on the undersides of leaves plus watch the margins of leaves for feeding. Bertha armyworm larvae will also feed on newly developing pods so the whole plant should be examined. Watch for the following life stages:
Scouting tips: ● Some bertha armyworm larvae remain green or pale brown throughout their larval life. ● Large larvae may drop off the plants and curl up when disturbed, a defensive behavior typical of cutworms and armyworms. ● Young larvae chew irregular holes in leaves, but normally cause little damage. The fifth and sixth instars cause the most damage by defoliation and seed pod consumption. Crop losses due to pod feeding will be most severe if there are few leaves. ● Larvae eat the outer green layer of the stems and pods exposing the white tissue. ● At maturity, in late summer or early fall, larvae burrow into the ground and form pupae. Monitoring: – Larval sampling should commence once the adult moths are noted. – Sample at least three locations, a minimum of 50 m apart. – At each location, mark an area of 1 m2 and beat the plants growing within that area to dislodge the larvae. – Count them and compare the average against the values in the economic threshold table below:
Bertha armyworm (Lepidoptera: Mamestra configurata) – Reporting sites across the prairies have generally reported lower cumulative interceptions with some exceptions in Saskatchewan. Scouting within fields now becomes important.
In-field monitoring for egg masses and newly emerged larvae (photo below) should initially focus on the undersides of leaves plus watch the margins of leaves for feeding. Bertha armyworm larvae will also feed on newly developing pods so the whole plant should be examined. Watch for the following life stages:
Scouting tips: ● Some bertha armyworm larvae remain green or pale brown throughout their larval life. ● Large larvae may drop off the plants and curl up when disturbed, a defensive behavior typical of cutworms and armyworms. ● Young larvae chew irregular holes in leaves, but normally cause little damage. The fifth and sixth instars cause the most damage by defoliation and seed pod consumption. Crop losses due to pod feeding will be most severe if there are few leaves. ● Larvae eat the outer green layer of the stems and pods exposing the white tissue. ● At maturity, in late summer or early fall, larvae burrow into the ground and form pupae.
Monitoring: – Larval sampling should commence once the adult moths are noted. – Sample at least three locations, a minimum of 50 m apart. – At each location, mark an area of 1 m2 and beat the plants growing within that area to dislodge the larvae. – Count them and compare the average against the values in the economic threshold table below:
Bertha armyworm parasitoids – Ichneumonids and Tachinids
Last year, the focus of the Insect of the Week was crop pests. This year, we’re changing things up and highlighting the many natural enemies that help you out, silently and efficiently killing off crop pests. [note: featured Insects of the Week in 2015 are available on the Insect of the Week page] This week’s Insects of the Week are tachinids, and ichneumonidae. The adult tachinid will feed on flower nectar, honeydew from aphids, scales, and mealybugs. The tachinid, Athrycia cinerea (Coq.), is a parasitoid of the Bertha armyworm. Ichneumonidae adults also eat nectar and aphid honeydow, however, its larvae (Banchus flavescens, Cresson) are parasitoids of Lepidoptera, Coleoptera, Diptera, Hymenoptera, and some spiders. For more information about these parasitoids, the other pests they control and other important crop and forage insects, see the new Field Crop and Forage Pests and their Natural Enemies in Western Canada – Identification and Management Field Guide for identification, life cycle and conservation options (download links for field guide available on the Insect of the Week page).
Bertha armyworm (Lepidoptera: Mamestra configurata) – This week, moths are expected to complete their yearly flight. Reporting sites across the prairies have generally reported lower cumulative interceptions with some exceptions in Saskatchewan.
Provincial staff coordinate BAW pheromone trapping across the prairies and summarize cumulative counts in report or map formats:
● Saskatchewanians.… Male moths have been intercepted at multiple sites in Saskatchewan with some sites reporting higher risk values (Insect Report-Issue #4, prepared by S. Hartley). ● Manitobans.…. Low numbers of male moths have been intercepted throughout the province but review the values in the most recent Insect and Disease Report prepared by J. Gavloski and posted June 22, 2016.
Bertha armyworm (Lepidoptera: Mamestra configurata) – Moths should have appeared in pheromone traps by now since all areas of arable prairie farmland are highlighted either yellow or orange in the map below.
Those monitoring BAW pheromone traps may want to compare trap “catches” to the following reference photo kindly shared by Saskatchewan Agriculture below:
Provincial staff coordinate BAW pheromone trapping across the prairies and summarize cumulative counts in report or map formats:
● Saskatchewanians.… Watch for future Insect Reports. ● Manitobans.…. Exceedingly low numbers of male moths were intercepted during the first week of monitoring (Insect and Disease Report posted June 15, 2016, prepared by J. Gavloski).
Bertha armyworm (Lepidoptera: Mamestra configurata) – Those monitoring BAW pheromone traps may want to compare trap “catches” to the following reference photo kindly shared by Saskatchewan Agriculture below:
Provincial staff coordinate BAW pheromone trapping across the prairies and summarize cumulative counts in report or map formats:
Bertha armyworm (Lepidoptera: Mamestra configurata) – Bertha armyworm (BAW) pupal
development is progressing well owing to the recent warmer weather. Moths
should have appeared in pheromone traps theweek
of June 5, 2016!
Those monitoring BAW pheromone traps may want to compare trap “catches” to the following reference photo kindly shared by Saskatchewan Agriculture below:
Provincial staff coordinate BAW pheromone trapping across the prairies and summarize cumulative counts in report or map formats:
Bertha armyworm (Lepidoptera: Mamestra configurata) – Bertha armyworm (BAW) pupal development is progressing well. Pheromone traps should be deployed in areas highlighted yellow in the map below.
Those monitoring BAW pheromone traps may want to compare trap “catches” to the following reference photo kindly shared by Saskatchewan Agriculture below:
Bertha armyworm (Lepidoptera: Mamestra configurata) – Bertha armyworm (BAW) pupal development is progressing well, particularly across AB. Pheromone traps should be deployed in areas highlighted yellow in the map below.
Those monitoring BAW pheromone traps may want to compare trap “catches” to the following reference photo kindly shared by Saskatchewan Agriculture below:
Bertha armyworm (Lepidoptera: Mamestra configurata) – Bertha armyworm (BAW) pupal development is progressing well, particularly across AB. Predicted pupal development is greater than 50% at Brooks, Vauxhaul, Hanna, Drumheller, Edmonton, AB and at Kindersley, SK.
Prairie Pest Monitoring Network Weekly Updates – August 12, 2015
Otani, Giffen, Svendsen, Olfert
Greetings! An HTML and PDF version of this Weekly Update can beaccessed here.
Weather synopsis – The following weather maps were retrieved from AAFC’s Drought Watch website. The map below shows the Highest Temperatures the Past 7 Days (July 29-August 10, 2015) across the prairies:
The map below shows the Accumulated Precipitation the past 7 days (i.e., July 29-August 10, 2015):
While the map below reflects the Accumulated Precipitation for the Growing Season (i.e., April 1-August 10, 2015):
The map below reflects the Percent of Normal Precipitation for the Growing Season (i.e., April 1-August 10, 2015) for comparison:
The updated growing degree day (GDD) (Base 5ºC, March 1 – August 9, 2015) map is below:
While the growing degree day (GDD) (Base 10ºC, March 1 – August 9, 2015) map is included below:
Pre-Harvest Interval (PHI) – Growers is late-season insect pest problems will need to remember to factor in the PHI which is the minimum number of days between a pesticide application and swathing or straight combining of a crop. The PHI recommends sufficient time for a pesticide to break down and a PHI-value is both crop- and pesticide-specific. Adhering to the PHI is important for a number of health-related reasons but also because Canada’s export customers of canola strictly regulate and test for the presence of trace residues of pesticides.
In 2013, the Canola Council of Canada created and circulated their “Spray to Swath Interval Calculator” which was intended to help canola growers accurately estimate their PHI. Other PHI are described in your provincial crop protection guides and remember that specific crop x pesticide combinations will mean different PHIs. A screen shot of the webpage is included below for your reference.
Bertha armyworm (Mamestra configurata) –In-field monitoring will focus on searching for Bertha armyworm larvae which will feed on leaves but also upon newly developing pods. Take care to examine the whole plant when scouting. Watch for the following life stages:
Reminder: Some bertha armyworm larvae remain green or pale brown throughout their larval life. Large larvae may drop off the plants and curl up when disturbed, a defensive behavior typical of cutworms and armyworms. Young larvae chew irregular holes in leaves, but normally cause little damage. The fifth and sixth instars cause the most damage by defoliation and seed pod consumption. Crop losses due to pod feeding will be most severe if there are few leaves. Larvae eat the outer green layer of the stems and pods exposing the white tissue. At maturity, in late summer or early fall, larvae burrow into the ground and form pupae.
Monitoring:
Sample at least three locations (a minimum of 50 m apart) within a field for larvae. At each location, mark an area of 1 m2 and beat the plants growing within that area to dislodge the larvae. Count them and compare the average against the values in the economic threshold table below:
Table 1. Economic thresholds for Bertha armyworm in canola (courtesy Manitoba Agriculture, Food and Rural Initiatives).
Expected Seed Value – $ / bushel*
Spraying cost –
$ / acre
6
7
8
9
10
11
12
13
14
15
16
Number of Larvae / metre2 *
7
20
17
15
13
12
11
10
9
9
8
8
8
23
20
17
15
14
13
11
11
10
9
9
9
26
22
19
17
16
14
13
12
11
10
10
10
29
25
22
19
17
16
14
13
12
11
11
11
32
27
24
21
19
17
16
15
14
13
12
12
34
30
26
23
21
19
17
16
15
14
13
13
37
32
28
25
22
20
19
17
16
15
14
14
40
35
31
27
24
22
20
19
17
16
15
15
43
37
32
29
26
23
22
20
19
17
16
* Economic thresholds for bertha armyworm are based on an assumed yield loss of 0.058 bu/acre for each larva/metre2 (Bracken and Bucher. 1977. Journal of Economic Entomology. 70: 701-705).
Diamondback Moth (Plutella xylostella) – In-field monitoring for DBM larvae should continue this week.
Larval Monitoring:
Once the diamondback moth is present in the area, it is important to monitor individual canola fields for larvae. Remove the plants in an area measuring 0.1 m2 (about 12″ square), beat them on to a clean surface and count the number of larvae dislodged from the plant. Repeat this procedure at least in five locations in the field to get an accurate count.
Remember, parasitoid wasps attacking DBM larvae (Refer to photo below) are already present in fields. Use the economic thresholds to preserve these beneficial wasps by NOT applying insecticide until DBM larval densities exceed the threshold.
Diamondback larva (upper left) and pupal silk cocoon (upper right), Diadegma insulare adult and early instar Diamondback moth larvae on canola leaf (lower left) and D. insulare pupae (N=2) within Diamondback moth pupal silk cocoons (lower right).
Economic threshold for diamondback moth in canola at the advanced pod stage is 20 to 30 larvae/ 0.1 m2 (approximately 2-3 larvae per plant). Economic thresholds for canola or mustard in the early flowering stage are not available. However, insecticide applications are likely required at larval densities of 10 to 15 larvae/ 0.1 m2 (approximately 1-2 larvae per plant).
Swede midge (Contarinia nasturtii) – Thank you to Dr. Lars Andreassen who provided the following update for swede midge monitoring in Saskatchewan for 2015. Very low swede midge numbers have been intercepted at pheromone trap monitoring sites across the prairies but these results are not surprising given the drought conditions. In-field surveying performed by Andreassen et al. (AAFC-Saskatoon) are mapped below for 2015. Their findings show consistent swede midge populations (larvae and damage symptoms) in northeast Saskatchewan in 2015. Note there are new records of larvae and swede midge damage at sites surrounding Lloydminster up against the Alberta border in 2015.
Reminder – Swede midge scouting tips for in-field monitoring:
Watch for unusual plant structures and plant discolourations then follow-up by closely scrutinizing the plant for larvae (Refer to Figure below for larvae among the anthers).
The growing tip may become distorted and produce several growing tips or none at all, young leaves may become swollen, crinkled or crumpled and brown scarring caused by larval feeding may be seen on the leaf petioles and stems.
Flowers may fail to open.
Youngplants that show unusual growth habits should be examined carefully for damageand larvae, especially if the sticky liners have many flies resembling midges (swede midges are about the size of orange blossom wheat midge but are not orange).
In 2014, Canola School posted a swede midge update entitled “ Swede midge a pest on the rise”, featuring Dr. Julie Soroka (AAFC-Saskatoon). The Ontario Canola Growers post swede midge information here. Dr. Rebecca Hallett has posted a very helpful swede midge identification guide for those performing in-field monitoring and pheromone trapping. Finally, canola management recommendations for swede midge in Ontario are posted by Rebecca Hallett and Brian Hall.
Cabbage seedpod weevil (Ceutorhynchus obstrictus) – There is one generation of CSPW per year and the overwintering stage is the adult which is an ash-grey weevil measuring 3-4mm long (Refer to lower left photo). Adults typically overwinter in soil beneath leaf litter within shelter belts and roadside ditches. They emerge from overwintering in the spring as soil temperatures warm to ~15°C. CSPW utilize several flowering hosts including wild mustard, flixweed, hoary cress, stinkweed and volunteer canola. CSPW move to canola during the bud to early flower stages and will feed on pollen and buds, causing flowers to die. Adult feeding damage to buds is more evident in dry years when canola is unable to compensate for bud loss. Adults mate following a pollen meal then the female will deposit a single egg through the wall of a developing pod or adjacent to a developing seed within the pod (refer to lower right photo). Eggs are oval and an opaque white, each measuring ~1mm long. Typically a single egg is laid per pod although, when CSPW densities are high, two or more eggs may be laid per pod.
There are four larval instar stages of the CSPW and each stage is white and grub-like in appearance ranging up to 5-6mm in length (refer to lower left photo). The first instar larva feeds on the cuticle on the outside of the pod while the second instar larva bores into the pod, feeding on the developing seeds. A single larva consumes about 5 canola seeds. The mature larva chews a small, circular exit hole from which it drops to the soil surface and pupation takes place in the soil within an earthen cell. Approximately 10 days later, the new adult emerges to feed on maturing canola pods. Later in the season these new adults migrate to overwintering sites beyond the field.
Monitoring: Begin sampling when the crop first enters the bud stage and continue through the flowering. Sweep net samples should be taken at ten locations within the field with ten 180° sweeps per location. Count the number of weevils at each location. Samples should be taken in the field perimeter as well as throughout the field. Adults will invade fields from the margins and if infestations are high in the borders, application of an insecticide to the field margins may be effective in reducing the population to levels below which economic injury will occur. An insecticide application is recommended when three to four weevils per sweep are collected and has been shown to be the most effective when canola is in the 10 to 20% bloom stage (2-4 days after flowering starts). Consider making insecticide applications late in the dayto reduce the impact on pollinators. Whenever possible, provide advanced warning of intended insecticide applications to commercial beekeepers operating in the vicinity to help protect foraging pollinators. High numbers of adults in the fall may indicate the potential for economic infestations the following spring.
Lygus bugs (Lygus spp.) – The economic threshold for Lygus in canola is applied at late flower and early pod stages. Biological and monitoring information can be linked by clicking here or you can access Manitoban, or Albertan fact sheets or the Prairie Pest Monitoring Network’s monitoring protocol.
Adult L. lineolaris (5-6 mm long) (photo: AAFC-Saskatoon).
Fifth instar lygus bug nymph (3-4 mm long) (photo: AAFC-Saskatoon).
Damage: Lygus bugs have piercing-sucking mouthparts and physically damage the plant by puncturing the tissue and sucking plant juices. The plants also react to the toxic saliva that the insects inject when they feed. Lygus bug infestations can cause alfalfa to have short stem internodes, excessive branching, and small, distorted leaves. They feed on buds and blossoms and cause them to drop. They also puncture seed pods and feed on the developing seeds causing them to turn brown and shrivel.
Begin monitoring canola when it bolts and continue until seeds within the pods are firm. Since adults can move into canola from alfalfa, check lygus bug numbers in canola when nearby alfalfa crops are cut.
Sample the crop for lygus bugs on a sunny day when the temperature is above 20°C and the crop canopy is dry. With a standard insect net (38 cm diameter), take ten 180° sweeps. Count the number of lygus bugs in the net.
Repeat the sampling in another 14 locations. Samples can be taken along or near the field margins. Calculate the cumulative total number of lygus bugs and then consult the sequential sampling chart (Figure C). If the total number is below the lower threshold line, no treatment is needed. If the total is below the upper threshold line, take more samples. If the total is on or above the upper threshold line, calculate the average number of lygus bugs per 10-sweep sample and consult the economic threshold table.
Sequential sampling for lygus bugs at late flowering stage in canola.
The economic threshold for lygus bugs in canola covers the end of the flowering (Table 1) and the early pod ripening stages (Table 2). Once the seeds have ripened to yellow or brown, the cost of controlling lygus bugs may exceed the damage they will cause prior to harvest, so insecticide application is not warranted.
Table 1. Economic thresholds for lygus bugs in canola at late flowering and early pod stages (Wise and Lamb 1998).
1 Canola crop stage estimated using Harper and Berkenkamp 1975).
2 Economic thresholds are based on an assumed loss of 0.1235 bu/ac per lygus bug caught in 10 sweeps (Wise and Lamb. 1998. The Canadian Entomologist. 130: 825-836).
Table 2. Economic thresholds for lygus bugs in canola at early pod stage (Wise and Lamb 1998).
3 Economic thresholds are based on an assumed loss of 0.0882 bu/ac per lygus bug caught in 10 sweeps (Wise and Lamb. 1998. The Canadian Entomologist. 130: 825-836).
Time of Swathing – The Canola Council of Canada created a guide to help growers estimate swathing time in canola. A screen shot of the downloadable guide has been included below for reference.
Harvest Sample Program – The Canadian Grain Commission is ready and willing to grade grain samples harvested in 2015. This is a FREE opportunity for growers to gain unofficial insight into the quality of their grain and to obtain valuable dockage information and details associated with damage or quality issues. More information on the Harvest Sample Program is available at the Canadian Grain Commission’s website or growers can register online to receive a kit to submit their grain. The following screen shot of the CGC webpage offers more details.
Provincial Insect Pest Updates – The following provincial websites have their pest updates posted so click the links to access their reports:
● Manitoba’s Insect and Disease Report (August 4, 2015) featuring lygus bugs and a reminder for the Fall grasshopper monitoring plus how it supports the 2016 grasshopper forecast map.
● Saskatchewan’s Insect Update (July 23, 2015) featuring descriptions of causes of white heads in wheat.
● Alberta’s Insect Update (Call of the Land audio report of August 6, 2015) featuring lygus bugs, aphids in cereals and diamondback moths.
Insect of the Week – Field Crop and Forage Pests and their Natural Enemies in Western Canada: Identification and Field Guide (2015) by Hugh Philip is a new publication from Agriculture and Agri-Food Canada. This growing season we will post an “Insect of the Week” in the form of short excerpts from the field guide. This week features the Beet webworm.
Crop Reports – The following provincial websites now have their Crop Reports posted so click the links to find their weekly updates:
West Nile Virus Risk –The regions most advanced in degree-day accumulations for Culex tarsalis, the vector for West Nile Virus, are shown in the map below. Areas highlighted in red on the map below will have accumulated sufficient heat for C. tarsalis to fly.
The Public Health Agency of Canada posts information related to West Nile Virus in Canada and their website is located here. The Canadian Wildlife Health Cooperative compiles and posts information related to their disease surveillance. As of this week, nine birds in Ontario and five birds in Quebec tested positive for West Nile-related deaths (click here to view the report).
As of August 9, 2015, adult C. tarsalis are predicted to be in flight throughout much of the prairies – apply DEET if you are active outdoors within areas highlighted red, rose or pink in the map below!! Areas highlighted orange should be prepared with DEET!
Questions or problems accessing the contents of this Weekly Update? Please e-mail either Dr. Owen Olfert or Jennifer Otani. Past and present “Weekly Updates” are very kindly posted to the Western Forum website by webmaster, Dr. Kelly Turkington. Please click here to link to that webpage.
Field Crop and Forage Pests and their Natural Enemies in Western Canada: Identification and management field guide – The NEW Field Guide to Support Integrated Pest Management (IPM) in Field and Forage Crops is NOW available for download from www.publications.gc.ca. Two downloadable (~8 MB) versions of the complete field guide are available as either a ‘Regular’ (i.e., best for printing: English, French) or ‘Enhanced’ (i.e., best for viewing electronically with active internal and external hyperlinks: English-enhanced, French-enhanced).
Wind trajectories Related to Diamondback Moth (DBM) and Aster Leafhopper Introductions – Completed for the season. Please refer to earlier Weekly Updates for details related to backward and forward trajectories associated with air parcels moving over western Canadian locations.
Flea Beetles (Chrysomelidae: Phyllotreta species) – Helpful images produced by Dr. Julie Soroka (AAFC-Saskatoon) exemplifying percent of cotyledon leaf area consumed by flea beetles are posted at Canola Watch.
Canola Insect Scouting Chart – The Canola Insect Scouting Chart has been updated with hyperlinks now directing growers to downloadable pages from the NEW Field Guide!
Alfalfa Weevil (Hypera postica) – Alfalfa growers are encouraged to check the Alfalfa Weevil Fact Sheet prepared by Dr. Julie Soroka (AAFC-Saskatoon).
Cabbage root maggot (Delia spp.) – A summary of root maggot biology, research, and pest management recommendations for canola production was published by Soroka and Dosdall (2011). Remember there are no registered insecticides for root maggot control in canola.
This week’s Insect of the Week is the Bertha armyworm(Mamestra configurata (Walker)) (from the new Field Crop and Forage Pests and their Natural Enemies in Western Canada – Identification and Management Field Guide – download links available on the Insect of the Week page).
Saskatchewan Agriculture just posted their 2015 Bertha Armyworm Map. The relative risk appears to be low based on cumulative pheromone trap counts to date but scroll down the webpage to access a PDF copy of the map.
Prairie Pest Monitoring Network Weekly Updates – July 15, 2015
Otani, Giffen, Svendsen, Olfert
Greetings! This week grasshoppers, cabbage seedpod weevil and wheat midge were important pests based on provincial reports and reminders for in-field scouting. Rain fell in some areas of the prairies but many continue to wait for moisture. Remember, a downloadable version of this Weekly Update can beaccessed here.
Weather synopsis – Thanks to the folks who compile and manage the agroclimate maps posted by AAFC! The map below shows the Accumulated Precipitation the past 7 days (i.e., July 7-13, 2015):
While the map below reflects the Accumulated Precipitation for the Growing Season (i.e., April 1-July 13, 2015):
The map below reflects the Percent of Normal Precipitation for the Growing Season (i.e., April 1-July 13, 2015) for comparison:
The map below shows the Lowest Temperatures the Past 7 Days (July 7-13, 2015) across the prairies:
While the map below shows the Highest Temperatures the Past 7 Days (July 7-13, 2015) across the prairies:
The updated growing degree day (GDD) (Base 5ºC, March 1 – July 12, 2015) map is below:
While the growing degree day (GDD) (Base 10ºC, March 1 – July 12, 2015) map is included below:
Bertha armyworm (Mamestra configurata) –Low cumulative counts of BAW moths were again reported in pheromone traps throughout the prairies this week.
Growers in Alberta can refer to the live 2015 Bertha armyworm map which is posted by Alberta Agriculture and Forestry that reflects cumulative counts of moths intercepted.
Growers in Manitoba can refer to the latest Insect and Disease Report (updated July 10, 2015) for BAW cumulative count updates.
In-field monitoring for egg masses (Refer to photo below) and newly emerged larvae (photo below) should initially focus on the undersides of leaves plus watch the margins of leaves for feeding. Bertha armyworm larvae will also feed on newly developing pods so the whole plant should be examined. Watch for the following life stages:
Reminder: Some bertha armyworm larvae remain green or pale brown throughout their larval life. Large larvae may drop off the plants and curl up when disturbed, a defensive behavior typical of cutworms and armyworms. Young larvae chew irregular holes in leaves, but normally cause little damage. The fifth and sixth instars cause the most damage by defoliation and seed pod consumption. Crop losses due to pod feeding will be most severe if there are few leaves. Larvae eat the outer green layer of the stems and pods exposing the white tissue. At maturity, in late summer or early fall, larvae burrow into the ground and form pupae.
Monitoring:
Larval sampling should commence once the adult moths are noted. Sample at least three locations, a minimum of 50 m apart. At each location, mark an area of 1 m2 and beat the plants growing within that area to dislodge the larvae. Count them and compare the average against the values in the economic threshold table below:
Table 1. Economic thresholds for Bertha armyworm in canola (courtesy Manitoba Agriculture, Food and Rural Initiatives).
Expected Seed Value – $ / bushel*
Spraying cost –
$ / acre
6
7
8
9
10
11
12
13
14
15
16
Number of Larvae / metre2 *
7
20
17
15
13
12
11
10
9
9
8
8
8
23
20
17
15
14
13
11
11
10
9
9
9
26
22
19
17
16
14
13
12
11
10
10
10
29
25
22
19
17
16
14
13
12
11
11
11
32
27
24
21
19
17
16
15
14
13
12
12
34
30
26
23
21
19
17
16
15
14
13
13
37
32
28
25
22
20
19
17
16
15
14
14
40
35
31
27
24
22
20
19
17
16
15
15
43
37
32
29
26
23
22
20
19
17
16
* Economic thresholds for bertha armyworm are based on an assumed yield loss of 0.058 bu/acre for each larva/metre2 (Bracken and Bucher. 1977. Journal of Economic Entomology. 70: 701-705).
Grasshoppers (Camnulla pellucida, Melanoplus sanguinipes, M. bivittattus, M. packardii) – In-field scouting along field margins and in ditches AND within the field is critical now with the exceedingly dry growing conditions!
Scouting – Remember only five or six grasshopper species of the 80+ that occur on the prairies are regarded as crop pests. The lifecycles of these six economically important species are similar. Nymphs hatch from overwintered eggs in the spring. Nymphs develop through five stages or instars before becoming adults. Typically, the most serious economic damage will occur from the third to fifth instar stages but all stages need to be monitored. The life stages of the clearwinged grasshopper (Camnulla pellucida) are shown below. Note that adults possess fully formed wings that extend the entire length of the abdomen.
Life stages of the clearwinged grasshopper include (left to right) eggs which overwinter, first instar nymphs that hatch in the spring followed by second, third, fourth and fifth instar nymphs which finally develop into the adult stage.
Need help distinguishing grasshopper nymph stages? Saskatchewan Agriculture’s latest Insect Update includes line drawings to help! It also includes a summary of economic thresholds for grasshoppers in various crops.
Diamondback Moth (Plutella xylostella) – In-field monitoring for DBM larvae should continue this week.
Larval Monitoring:
Once the diamondback moth is present in the area, it is important to monitor individual canola fields for larvae. Remove the plants in an area measuring 0.1 m2 (about 12″ square), beat them on to a clean surface and count the number of larvae dislodged from the plant. Repeat this procedure at least in five locations in the field to get an accurate count.
Remember, parasitoid wasps attacking DBM larvae (Refer to photo below) are already present in fields. Use the economic thresholds to preserve these beneficial wasps by NOT applying insecticide until DBM larval densities exceed the threshold.
Diamondback larva (upper left) and pupal silk cocoon (upper right), Diadegma insulare adult and early instar Diamondback moth larvae on canola leaf (lower left) and D. insulare pupae (N=2) within Diamondback moth pupal silk cocoons (lower right).
Economic threshold for diamondback moth in canola at the advanced pod stage is 20 to 30 larvae/ 0.1 m2 (approximately 2-3 larvae per plant). Economic thresholds for canola or mustard in the early flowering stage are not available. However, insecticide applications are likely required at larval densities of 10 to 15 larvae/ 0.1 m2 (approximately 1-2 larvae per plant).
Wheat Midge (Sitodiplosis mosellana) – This season, predictive modelling was used in an attempt to forecast wheat midge emergence. In 2014, the degree-day model proposed by German researchers (Basedow) was used to predict adult midge emergence in the Peace River region compared to the 5°C base temperature model which corresponds well to midge emergence throughout central and southern areas of the prairies. The map below predicts the geographic distribution and corresponding accumulation of heat units necessary for wheat midge to emerge from puparia developing in the soil.
The map below indicates the predicted status of wheat midge emergence with 10% of resident midge population emerged in areas highlighted yellow (600-693 DD), 50% in areas highlighted gold (693-784 DD), and 90% of resident midge emerged in areas highlighted orange (784-874 DD) using current weather data (up to July 12, 2015). Wheat midge emergence is predicted to be 100% completed (as of July 12, 2015) with the initial midge larvae now expected to be found within wheat heads growing in southern Alberta, southeast Saskatchewan, southwest Manitoba and to the south of Winnipeg. Wheat midge emergence is predicted to be 90% completed (as of July 12, 2015) throughout most of the boreal region of the prairies and in the north Peace. Wheat midge emergence is predicted to be 50% completed (as of July 12, 2015) throughout the remaining portions of the prairies.
When monitoring wheat fields, pay attention to the synchrony between flying midge and anthesis. Additional wheat midge biology and monitoring information can be located by clicking here or linking to your provincial fact sheet (Saskatchewan Agricultureor Alberta Agriculture and Forestry). More information related to wheat midge on the Canadian prairies was published by Elliott, Olfert, and Hartley in 2011.
REMEMBER that in-field counts of wheat midge per head remain the basis of economic threshold decision. Also remember that the parasitoid, Macroglenes penetrans (shown below), is actively searching for wheat midge at the same time. Preserve this parasitoid whenever possible and remember your insecticide control options for wheat midge also kill these beneficial insects which help reduce midge populations.
In-field monitoring for wheat midge should be carried out in the evening (preferably after 8:30 pm or later) when the female midges are most active. On warm (at least 15ºC), calm evenings, the midge can be observed in the field, laying their eggs on the wheat heads. Midge populations can be estimated by counting the number of adults present on 4 or 5 wheat heads. Inspect the field daily in at least 3 or 4 locations during the evening.
Economic Thresholds for Wheat Midge:
To maintain optimum grade: 1 adult midge per 8 to 10 wheat heads during the susceptible stage.
For yield only: 1 adult midge per 4 to 5 heads. At this level of infestation, wheat yields will be reduced by approximately 15% if the midge is not controlled.
Inspect the developing kernels for the presence of larvae and the larval damage.
Adult: Adult cereal leaf beetles (CLB) have shiny bluish-black wing-covers (Refer to figure below). 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 shelterbelts, deciduous and conifer forests. They emerge in the spring once temperature reaches 10-5ºC and are active for about 6 weeks. They usually begin feeding on grasses, then move into winter cereals and later into spring cereals.
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 (Refer to figure below). When the larva completes its growth, it drops to the ground and pupates in the soil.
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.
Cereal leaf beetle adult (left) and larva (right).
Leaf damage resulting from feeding by cereal leaf beetle larvae.
Monitoring:
Give priority to following factors when selecting monitoring sites:
□ Choose fields and sections of the fields with past or present damage symptoms.
□ Choose fields that are well irrigated (leaves are dark green in color), including young, lush crops. Areas of a field under stress and not as lush (yellow) are less likely to support CLB.
□ Monitor fields located along riparian corridors, roads and railroads.
□ Survey field areas situated near brush cover or weeds, easy to access, or are nearby sheltered areas such as hedge rows, forest edges, fence lines, etc.
Focus your site selection on the following host plant priorities:
● First – winter wheat. If no winter wheat is present then;
● Second – other cereal crops (barley, wheat, oats, and rye). If no cereal crops are present then;
● Third – hay crops. If no hay crops or cereal crops are present then;
● Fourth – ditches and water corridors
Sweep-net Sampling for Adults and Larvae:
A sweep is defined as a one pass (from left to right, executing a full 180 degrees) through the upper foliage of the crop using a 37.5 cm diameter sweep-net. A sample is defined as 100 sweeps taken at a moderate walking pace collected 4-5 meters inside the border of a field. At each site, four samples should be collected, totaling 400 sweeps per site. The contents of each sample should be visually inspected for life stages of CLB and all suspect specimens should be retained for identification. Please note that, because the CLB larvae are covered in a sticky secretion, when they are caught in a sweep-net they are often covered in debris and are very difficult to see. To help determine the presence of CLB, place the contents of the sweep net into a large plastic bag for observation.
Visual Inspection:
Both the adults and larvae severely damage plants by chewing out long strips of tissue between the veins of leaves, leaving only a thin membrane. When damage is extensive, leaves turn whitish (Figure 14). The plant may be killed or the crop may be seriously reduced. In addition to feeding damage, inspectors should be looking for all life stages of the CLB. In a field of host material the visual survey should be conducted between “sweep samples”. Other locations to be examined include grass covered ditch banks and young host crops that are too low to sweep. Experienced surveyors should spend 15 minutes on visual inspection. Less experience surveyors should spend an additional 10 minutes on the visual component.
Swede midge (Contarinia nasturtii) – Reminder – This season we again include scouting tips for in-field monitoring:
□ Watch for unusual plant structures and plant discolourations then follow-up by closely scrutinizing the plant for larvae (Refer to Figure below).
□ The growing tip may become distorted and produce several growing tips or none at all, young leaves may become swollen, crinkled or crumpled and brown scarring caused by larval feeding may be seen on the leaf petioles and stems.
□ Flowers may fail to open.
□ Youngplants that show unusual growth habits should be examined carefully for damageand larvae, especially if the sticky liners have many flies resembling midges (swede midges are about the size of orange blossom wheat midge but are not orange).
□ Larvae can be seen with a hand lens.
In 2014, Canola School posted a swede midge update entitled “ Swede midge a pest on the rise”, featuring Dr. Julie Soroka (AAFC-Saskatoon). The Ontario Canola Growers post swede midge information here. Dr. Rebecca Hallett has posted a very helpful swede midge identification guide for those performing in-field monitoring and pheromone trapping. Finally, canola management recommendations for swede midge in Ontario are posted by Rebecca Hallett and Brian Hall.
Cabbage seedpod weevil (Ceutorhynchus obstrictus) – There is one generation of CSPW per year and the overwintering stage is the adult which is an ash-grey weevil measuring 3-4mm long (Refer to lower left photo). Adults typically overwinter in soil beneath leaf litter within shelter belts and roadside ditches. They emerge from overwintering in the spring as soil temperatures warm to ~15°C. CSPW utilize several flowering hosts including wild mustard, flixweed, hoary cress, stinkweed and volunteer canola. CSPW move to canola during the bud to early flower stages and will feed on pollen and buds, causing flowers to die. Adult feeding damage to buds is more evident in dry years when canola is unable to compensate for bud loss. Adults mate following a pollen meal then the female will deposit a single egg through the wall of a developing pod or adjacent to a developing seed within the pod (refer to lower right photo). Eggs are oval and an opaque white, each measuring ~1mm long. Typically a single egg is laid per pod although, when CSPW densities are high, two or more eggs may be laid per pod.
There are four larval instar stages of the CSPW and each stage is white and grub-like in appearance ranging up to 5-6mm in length (refer to lower left photo). The first instar larva feeds on the cuticle on the outside of the pod while the second instar larva bores into the pod, feeding on the developing seeds. A single larva consumes about 5 canola seeds. The mature larva chews a small, circular exit hole from which it drops to the soil surface and pupation takes place in the soil within an earthen cell. Approximately 10 days later, the new adult emerges to feed on maturing canola pods. Later in the season these new adults migrate to overwintering sites beyond the field.
Monitoring: Begin sampling when the crop first enters the bud stage and continue through the flowering. Sweep net samples should be taken at ten locations within the field with ten 180° sweeps per location. Count the number of weevils at each location. Samples should be taken in the field perimeter as well as throughout the field. Adults will invade fields from the margins and if infestations are high in the borders, application of an insecticide to the field margins may be effective in reducing the population to levels below which economic injury will occur. An insecticide application is recommended when three to four weevils per sweep are collected and has been shown to be the most effective when canola is in the 10 to 20% bloom stage (2-4 days after flowering starts). Consider making insecticide applications late in the dayto reduce the impact on pollinators. Whenever possible, provide advanced warning of intended insecticide applications to commercial beekeepers operating in the vicinity to help protect foraging pollinators. High numbers of adults in the fall may indicate the potential for economic infestations the following spring.
Cabbage root maggot (Delia spp.) – Among root feeding pests of canola, historically five species of Delia flies have been identified across the Canadian prairies; Delia radicum (L.), D. floralis (Fallén), D. platura (Meigan), D. planipalpis (Stein), and D. florilega (Zett.) have been observed in canola over 30 years of research (Liu and Butts 1982, Griffiths 1986a, Broatch and Vernon 1997; Soroka and Dosdall 2011). A summary of root maggot biology, research, and pest management recommendations for canola production was published by Soroka and Dosdall (2011).
Root maggots continue to be a problematic in canola production largely owing to the fact that (i) the species is composition varies by geographic latitude and local conditions, plus (ii) one or two generations per year will occur but varies by species. The species complex is typically characterized by multiple, overlapping generations of Delia resulting in adults laying eggs in canola (Refer to upper left photo for adult and eggs) from late Spring to October and maggots feeding on roots from late rosette until late fall (Refer to upper right photo). Root maggots pupate and overwinter within cigar-shaped, reddish-brown puparia 5-20 cm below the soil surface (Soroka and Dosdall 2011) so canola-on-canola rotations should be avoided. In the spring, adults emerge from mid-May to mate and females lay oval, white eggs singly or in batches near the base of cruciferous host plants over a 5-6 week period. The larvae develop through three instar stages which feed on root hairs then secondary roots initially whereas older maggots will feed into the taproot of a canola plant.
Remember there is no registered insecticide for root maggot control in canola.
Lygus bugs (Lygus spp.) – The economic threshold for Lygus in canola is applied at late flower and early pod stages. Biological and monitoring information can be linked by clicking here or you can access the Manitoba, or Alberta fact sheets or the Prairie Pest Monitoring Network’s monitoring protocol.
Adult L. lineolaris (5-6 mm long) (photo: AAFC-Saskatoon).
Fifth instar lygus bug nymph (3-4 mm long) (photo: AAFC-Saskatoon).
Damage: Lygus bugs have piercing-sucking mouthparts and physically damage the plant by puncturing the tissue and sucking plant juices. The plants also react to the toxic saliva that the insects inject when they feed. Lygus bug infestations can cause alfalfa to have short stem internodes, excessive branching, and small, distorted leaves. They feed on buds and blossoms and cause them to drop. They also puncture seed pods and feed on the developing seeds causing them to turn brown and shrivel.
Begin monitoring canola when it bolts and continue until seeds within the pods are firm. Since adults can move into canola from alfalfa, check lygus bug numbers in canola when nearby alfalfa crops are cut.
Sample the crop for lygus bugs on a sunny day when the temperature is above 20°C and the crop canopy is dry. With a standard insect net (38 cm diameter), take ten 180° sweeps. Count the number of lygus bugs in the net.
Repeat the sampling in another 14 locations. Samples can be taken along or near the field margins. Calculate the cumulative total number of lygus bugs and then consult the sequential sampling chart (Figure C). If the total number is below the lower threshold line, no treatment is needed. If the total is below the upper threshold line, take more samples. If the total is on or above the upper threshold line, calculate the average number of lygus bugs per 10-sweep sample and consult the economic threshold table.
Sequential sampling for lygus bugs at late flowering stage in canola.
The economic threshold for lygus bugs in canola covers the end of the flowering (Table 1) and the early pod ripening stages (Table 2). Once the seeds have ripened to yellow or brown, the cost of controlling lygus bugs may exceed the damage they will cause prior to harvest, so insecticide application is not warranted.
Consider the estimated cost of spraying and expected return prior to making a decision to treat a crop. Remember that insecticide applications at bud stage in canola have not been proven to result in an economic benefit in production. The exception to this is in the Peace River region where early, dry springs and unusually high densities of lygus bug adults can occasionally occur at bud stage. In this situation, high numbers of lygus bugs feeding on moisture-stressed canola at bud stage is suspected to result in delay of flowering so producers in that region must monitor in fields that fail to flower as expected.
Table 1. Economic thresholds for lygus bugs in canola at late flowering and early pod stages (Wise and Lamb 1998).
1 Canola crop stage estimated using Harper and Berkenkamp 1975).
2 Economic thresholds are based on an assumed loss of 0.1235 bu/ac per lygus bug caught in 10 sweeps (Wise and Lamb. 1998. The Canadian Entomologist. 130: 825-836).
Table 2. Economic thresholds for lygus bugs in canola at pod stage (Wise and Lamb 1998).
3 Economic thresholds are based on an assumed loss of 0.0882 bu/ac per lygus bug caught in 10 sweeps (Wise and Lamb. 1998. The Canadian Entomologist. 130: 825-836).
Provincial Insect Pest Updates – The following provincial websites have their pest updates posted so click the links to access their reports:
● Alberta’s Insect Update (Call of the Land audio report of July 16, 2015)
Insect of the Week – Field Crop and Forage Pests and their Natural Enemies in Western Canada: Identification and Field Guide (2015) by Hugh Philip is a new publication from Agriculture and Agri-Food Canada. This growing season we will post an “Insect of the Week” in the form of short excerpts from the field guide. This week features several species of aphids (i.e., corn leaf, English grain, green peach, oat-birdcherry, pea, potato, soybean, turnip, greenbug).
Additionally, ladybird beetles were also featured in the Insect of the Week.
Crop Reports – The following provincial websites now have their Crop Reports posted so click the links to find their weekly updates:
West Nile Virus Risk – Reminder – Now is the time for DEET!The regions most advanced in degree-day accumulations for Culex tarsalis, the vector for West Nile Virus, are shown in the map below. Areas yet to be highlighted in red on the map below will have accumulated sufficient heat for C. tarsalis to fly. As of July 12, 2015, the predicted development of C. tarsalis is most advanced in the southern areas of our prairie provinces with adults predicted to emerge from 350-400 DD in the map below ( will be highlighted in red).
The Public Health Agency of Canada posts information related to West Nile Virus in Canada and their website is located here. The Canadian Wildlife Health Cooperative compiles and posts information related to their disease surveillance. As of this week, one bird in New Brunswick and one bird in Ontario tested positive for West Nile-related deaths (click here to view the report).
Questions or problems accessing the contents of this Weekly Update? Please e-mail or call either Owen.Olfert@agr.gc.ca (tel. 306-385-9355) or Jennifer.Otani@agr.gc.ca (tel. 780-354-5132). Past and present “Weekly Updates” are very kindly posted to the Western Forum website by webmaster, Dr. Kelly Turkington. Please click here to link to that webpage.
Field Crop and Forage Pests and their Natural Enemies in Western Canada: Identification and management field guide – The NEW Field Guide to Support Integrated Pest Management (IPM) in Field and Forage Crops is NOW available for download from www.publications.gc.ca. Two downloadable (~8 MB) versions of the complete field guide are available as either a ‘Regular’ (i.e., best for printing: English, French) or ‘Enhanced’ (i.e., best for viewing electronically with active internal and external hyperlinks: English-enhanced, French-enhanced).
Wind trajectories Related to Diamondback Moth (DBM) and Aster Leafhopper Introductions – Completed for the season. Please refer to earlier Weekly Updates for details related to backward and forward trajectories associated with air parcels moving over western Canadian locations.
Flea Beetles (Chrysomelidae: Phyllotreta species) – Helpful images produced by Dr. Julie Soroka (AAFC-Saskatoon) exemplifying percent of cotyledon leaf area consumed by flea beetles are posted at Canola Watch.
Cutworms (Noctuidae) – Cutworm biology, species information, plus monitoring recommendations are available at the Prairie Pest Monitoring Network’s Cutworm Monitoring Protocol. Also refer to these cutworm-specific fact sheets (Manitoba Agriculture and Rural Initiatives, Alberta Agriculture, Food and Rural Development). If cutworms are spotted in Albertan fields, please also consider using the Alberta Pest Surveillance Network’s “2015 Cutworm Reporting Tool” for online reporting located by clicking here. Data entered at that website uploads to a live “Cutworm Map”.
Canola Insect Scouting Chart – Reminder – The Canola Insect Scouting Chart has been updated with hyperlinks now directing growers to downloadable pages from the NEW Field Guide!
Alfalfa Weevil (Hypera postica) – Alfalfa growers are encouraged to check the Alfalfa Weevil Fact Sheet prepared by Dr. Julie Soroka (AAFC-Saskatoon).
In 2014, the PPMN compiled data for the following sites highlighted in the map below. The monitoring data collected from these sites forms invaluable sources of information both now and into the future.
Agricultural people from federal, provincial, regional and industry sectors all contribute to this tremendous effort! Monitoring at sites like these below provides crucial information on insect pest risk before and during the growing season. Some sites are visited annually while others are checked weekly and all that data enables the synthesis and generation of risk and forecast maps like those posted here.
THANK YOU to all who contribute!
Please contact Dr. Owen Olfert at AAFC-Saskatoon for more information about this map.
