Weather synopsis

This past week (Aug 4-10, 2020) conditions were generally warm and dry. Weekly prairie temperatures were warmest across Manitoba and Saskatchewan (Fig. 1). Lower temperatures were observed across western and northwestern Alberta (Fig. 1). Though average 30-day (July 12 – August 10, 2020) temperatures continue to be cooler in Alberta than eastern Saskatchewan and Manitoba (Fig. 2), temperature anomalies (mean temperature difference from average; July 14-August 10, 2020) indicate that conditions have generally been warmer than average across most of Alberta as well as Parkland regions of Saskatchewan and Manitoba (Fig. 3).

Figure 1. Observed average temperatures across the Canadian prairies the past seven days (August 4-10, 2020).
Figure 2. Observed average temperatures across the Canadian prairies the past 30 days (July 12-August 10, 2020).
Figure 3. Mean temperature difference from Normal the past 30 days (July 14-August 12, 2020).
Image has not been reproduced in affiliation with, or with the endorsement of the Government of Canada and was retrieved (12Aug2020). Access the full map at http://www.agr.gc.ca/DW-GS/current-actuelles.jspx?lang=eng&jsEnabled=true&reset=1588297059209

Regions in southeastern central and southern Saskatchewan and across southern Manitoba have reported temperatures that have been up to 2 °C cooler than average. Based on growing season temperatures (April 1-August 10, 2020) temperatures were warmest across the southern prairies (Fig. 4). Based on growing season temperature deviations (observed temperatures compared with climate normal temperatures), below average temperatures have been observed across central and western regions of Saskatchewan and central regions of Alberta (Fig. 5). Across southern Alberta and most of Manitoba, temperatures have generally been above average. (Fig. 5)

Figure 4. Observed average temperatures across the Canadian prairies for the growing season (April 1-August 10, 2020).
Figure 5. Observed difference from average temperatures across the Canadian prairies for the growing season (April 1-August 10, 2020).

Most areas reported 7-day cumulative rainfall amounts that were less than 10 mm (Fig. 6). Cumulative 30-day rainfall was lowest across a large area ranging across southern Alberta as well as central and western regions of Saskatchewan (Fig. 7). Growing season rainfall (percent of average) is highly variable across the prairies (Fig. 8). Rainfall has been below normal across most of Saskatchewan as well as southern Alberta, and the Peace River region (Fig. 8).

Figure 6. Observed cumulative precipitation across the Canadian prairies the past seven days (August 4-10, 2020).
Figure 7. Observed cumulative precipitation across the Canadian prairies the past 30 days (July 12-August 10, 2020).
Figure 8. Percent of average precipitation for the growing season (April 1-August 10, 2020).
Image has not been reproduced in affiliation with, or with the endorsement of the Government of Canada and was retrieved (12Aug2020). Access the full map at http://www.agr.gc.ca/DW-GS/current-actuelles.jspx?lang=eng&jsEnabled=true&reset=1588297059209

The growing degree day map (GDD) (Base 5 ºC, April 1-August 9, 2020) is below (Fig. 9) while the growing degree day map (GDD) (Base 10 ºC, April 1-August 9, 2020) is shown in Figure 10.

Figure 9. Growing degree day map (Base 5 °C) observed across the Canadian prairies for the growing season (April 1-August 9, 2020).
Figure 10. Growing degree day map (Base 10 °C) observed across the Canadian prairies for the growing season (April 1-August 9, 2020).

The highest temperatures (°C) observed across the Canadian prairies the past seven days ranged from <17 to >34 °C (Fig. 11) while the lowest temperatures ranged from <-1 to >13 °C (Fig. 12). So far this growing season (as of August 12, 2020), the number of days above 25 °C ranges from 0-10 days in the west (to west of Calgary, west and north of central Alberta and extending into the south and west of the Peace River region) but extends up to 51-60 days in southern Manitoba (Fig. 13).

Figure 11. Highest temperatures (°C) observed across the Canadian prairies the past seven days (April 1-August 12, 2020).
Image has not been reproduced in affiliation with, or with the endorsement of the Government of Canada and was retrieved (13Aug2020). Access the full map at http://www.agr.gc.ca/DW-GS/current-actuelles.jspx?lang=eng&jsEnabled=true&reset=1588297059209
Figure 12. Lowest temperatures (°C) observed across the Canadian prairies the past seven days (April 1-August 12, 2020).
Image has not been reproduced in affiliation with, or with the endorsement of the Government of Canada and was retrieved (13Aug2020). Access the full map at http://www.agr.gc.ca/DW-GS/current-actuelles.jspx?lang=eng&jsEnabled=true&reset=1588297059209
Figure 13. Number of days above 25 °C observed across the Canadian prairies this growing season (April 1-August 12, 2020).
Image has not been reproduced in affiliation with, or with the endorsement of the Government of Canada and was retrieved (13Aug2020). Access the full map at http://www.agr.gc.ca/DW-GS/current-actuelles.jspx?lang=eng&jsEnabled=true&reset=1588297059209

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

Bertha armyworm

Weekly Pheromone-baited Trapping Results – Click each province name to access moth reporting numbers observed in AlbertaSaskatchewan 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! 

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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 ManitobaSaskatchewanAlberta 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.

Predicted diamondback moth development

This week, the DBM model based on Harcourt (1954) was run with a biofix of May 15, 2020. Most of Alberta has had two generations. It is possible that three generations have been completed across Saskatchewan and southeastern Alberta where it has been warmer. Results indicate that a potential fourth generation may be occurring across southern Manitoba. DBM densities generally increase with increasing numbers of generations. Later maturing canola fields may be susceptible to damage resulting from larval feeding.

Figure 1. Using a biofix date of May 15, 2020, the projected number of diamondback moth (Plutella xylostella) generations across the Canadian prairies as of August 10, 2020.

Monitoring:

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 (Fig. 2) dislodged from the plant. Repeat this procedure at least in five locations in the field to get an accurate count.

This image has an empty alt attribute; its file name is DBM_Larva_AAFC.jpg
Figure 2. Diamondback larva measuring ~8mm long.
Note brown head capsule and forked appearance of prolegs on posterior.
This image has an empty alt attribute; its file name is DBM_Pupa_AAFC-1.jpg
Figure 3. Diamondback moth pupa within silken cocoon.

Economic threshold for diamondback moth in canola at the advanced pod stage is 20 to 30 larvae/ 0.1  (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).

This image has an empty alt attribute; its file name is DBM_adult_AAFC-1.png
Figure 4. Diamondback moth.

Biological and monitoring information for DBM is posted by Manitoba AgricultureSaskatchewan Agriculture, and the Prairie Pest Monitoring Network.  

More information about Diamondback moths can be found by accessing the pages from the  “Field Crop and Forage Pests and their Natural Enemies in Western Canada: Identification and Field Guide“.  View ONLY the Diamondback moth page but remember the guide is available as a free downloadable document as both an English-enhanced or French-enhanced version.

Predicted grasshopper development

As of August 10, 2020, the grasshopper model estimates that prairie grasshopper populations are primarily in the adult stage (Fig. 1). Figure 2 provides an overview of where oviposition is predicted to occur based on weather conditions up to August 10. Oviposition is well underway across southern Manitoba and southeastern Saskatchewan (Fig. 2).

Figure 1. Predicted average development stages of grasshopper (Melanoplus sanguinipes) populations across the Canadian prairies (as of August 10, 2020).
Figure 2. Predicted oviposition for (Melanoplus sanguinipes) populations across the Canadian prairies (as of August 10, 2020).

Recent warm weather in southwestern Alberta has resulted in increased development rates, resulting in predicted occurrence of oviposition. The three graphs compare grasshopper development at Grande Prairie (Fig. 3), Saskatoon (Fig. 4) and Brandon (Fig. 5). Output suggests that adults are beginning to occur near Grande Prairie but oviposition has yet to begin (Fig. 3). Saskatoon (Fig. 4) and Brandon (Fig. 5) populations should be primarily in the adult stage and oviposition should be well underway.

Figure 3. Predicted grasshopper (Melanoplus sanguinipes) phenology at Grande Prairie AB. Values are based on model simulations (April 1-August 10, 2020).
Figure 4. Predicted grasshopper (Melanoplus sanguinipes) phenology at Saskatoon SK. Values are based on model simulations (April 1-August 10, 2020).
Figure 5. Predicted grasshopper (Melanoplus sanguinipes) phenology at Brandon MB. Values are based on model simulations (April 1-August 10, 2020).

Biological and monitoring information related to grasshoppers in field crops is posted by Manitoba AgricultureSaskatchewan AgricultureAlberta Agriculture and Forestry, the BC Ministry of Agriculture and the Prairie Pest Monitoring Network.  Also refer to the grasshopper pages within the “Field Crop and Forage Pests and their Natural Enemies in Western Canada: Identification and management field guide” (Philip et al. 2018) as an English-enhanced or French-enhanced version.

Stored grain insect survey in Manitoba

Entomologists with Agriculture and Agri-Food Canada in Winnipeg are doing a survey in September of insects in farm grain bins. They are looking for 10 farms not far from Winnipeg where they can access grain bins to sample insects. No grain will be removed, just insects. If interested, please contact John Gavloski (John.Gavloski@gov.mb.ca) as soon as possible.

Stored product pests

Reminder – The Canadian Grain Commission’s website has an online key to stored product pests.  Growers managing grain storage can find an online identification tool for stored product pests (e.g., Rusty grain beetleRed flour beetleConfused flour beetleSaw-toothed grain beetle, and more).  The online tool features excellent diagnostic photos.  A screen shot of the Canadian Grain Commission’s “Identify an Insect” webpage is included below for reference.

This image has an empty alt attribute; its file name is 2020Aug06_CGC_Snip-1024x746.png

West nile virus risk

Health Canada posts information related to West Nile Virus in Canada and also tracks West Nile Virus through humanmosquitobird and horse surveillance.  Link here to access the most current weekly update (reporting date July 12-18, 2020; retrieved Aug 13, 2020). The screenshot below (retrieved Aug 13, 2020) serves as reference but access that Health Canada information here.

This image has an empty alt attribute; its file name is 2020Jun28-Jul04_WNV_Weekly_HealthCanada-1024x593.png

The following is offered to predict when Culex tarsalis, the vector for West Nile Virus, will begin to fly across the Canadian prairies (Fig. 1). This week, regions most advanced in degree-day accumulations for Culex tarsalis are shown in the map below (yellow, orange then red highlighted areas).  As of August 9, 2020 (Fig. 1), areas highlighted yellow and more imminently orange are approaching sufficient heat accumulation for mosquitoes to emerge.  Areas highlighted red NOW HAVE Culex tarsalis flying (Fig. 1) – protect yourself by wearing DEET!  

Figure 1. Predicted development of Culex tarsalis, across the Canadian prairies (as of August 9, 2020).

Harvest Sample Program

The Canadian Grain Commission is ready to grade grain samples harvested in 2020.  Samples are accepted up to November 30 but growers normally send samples as soon as harvest is complete.

This is a FREE opportunity for growers to gain unofficial insight into the quality of grain and to obtain valuable dockage information and details associated with damage or quality issues.  The data collected also helps Canada market its grain to the world!

More information on the Harvest Sample Program is available at the Canadian Grain Commission’s website where growers can register online to receive a kit to submit their grain.  

In exchange for your samples, the CGC assesses and provides the following unofficial results FOR FREE:

  • unofficial grade
  • dockage assessment on canola
  • protein content on barley, beans, chick peas, lentils, oats, peas and wheat
  • oil, protein and chlorophyll content for canola
  • oil and protein content and iodine value for flaxseed
  • oil and protein for mustard seed and soybean
  • Falling Number for wheat
  • Vomitoxin (deoxynivalenol or DON) for wheat and corn.

It can be helpful to have grade and quality information on samples before delivering their grain. Read brochures produced by the Canadian Grain Commission describing the Harvest Sample Program and details specific to the Western version of the program.

Provincial insect pest report links

Provincial entomologists provide insect pest updates throughout the growing season so link to their information: 

Manitoba‘s Crop Pest Updates for 2020 are available. Access the August 11 2020 report. The summary indicates that, “Grasshoppers continue to be the insect of greatest concern. The diamondback moth populations in eastern Manitoba that were of concern in some fields a couple of weeks ago seem to have diminished. Spider mites are being noticed in some soybean fields, but no insecticide applications for them have been reported yet.”

Saskatchewan‘s Crop Production News (for Issue 7). Read Issue 7 which includes articles on Pest Scouting 101- Harvest, Promoting and Enhancing Beneficial Insects, and What to Do with Unwanted Pesticides and Obsolete Livestock Medications. Issue 5 included articles on Bertha armyworm, Cabbage seedpod weevil,  FieldWatch – Fostering Communication Between Applicators and Producers, and Look What the Wind Blew in! Diamondback Moths Arrived Early This Spring. Issue #4 included articles on Pest Scouting 101: Mid-Summer, and The Wheat Midge.

•  Alberta Agriculture and Forestry’s Agri-News occasionally includes insect-related information or Twitter users can connect to #ABBugChat Wednesdays at 10:00 am.

Crop report links

Click the provincial name below to link to online crop reports produced by:

• Manitoba Agriculture and Rural Initiatives – Other viewing options include subscribing to receive or access a PDF of August 11, 2020 report.

• Saskatchewan Agriculture  or access a PDF of August 10, 2020 report.

• Alberta Agriculture and Forestry or access a PDF of July 28, 2020 report.

The following crop reports are also available:

• The United States Department of Agriculture (USDA) produces a Crop Progress Report (read the August 10, 2020 edition).

• The USDA’s Weekly Weather and Crop Bulletin (read the August 11, 2020 edition). 

Previous posts

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

    • 2019-2020 Risk and forecast maps

    • Alfalfa weevil (Wk08)

    • Aphid mummies (Wk15)

    • Aster leafhopper (Wk05)

    • Beetle data please! (Wk03)

    • Bertha armyworm – predicted development (Wk15)

    • Cereal aphid APP (Wk11)

    • Crop protection guides (Wk02)

    • Cutworms (Wk02)

    • Diamondback moth (Wk11)

    • Flea beetles (Wk02)

    • Field heroes (Wk14)

    • John Doane (Wk10)

    • Ladybird beetles (Wk15)

    • Lygus bugs in canola (Wk15)

    • Monarch migration (Wk10)

    • Pea leaf weevil (Wk11)

    • Pea leaf weevil – predicted development (Wk09)

    • Prairie provincial insect webpages (Wk02)

    • Wheat midge (Wk13)

    • Scouting charts – canola and flax (Wk02)

    • Thrips in canola (Wk15)

    • Ticks and Lyme Disease (Wk06)

    • Wind trajectories (Wk09)

    • West nile virus (Wk14)

RYE PESTS / FEATURE ENTOMOLOGIST: HALEY CATTON

This week’s Insect of the Week feature crop is is rye, a cold and drought resistant grain with various uses, including bread and cereal production, and brewing and malting. Our feature entomologist this week is Haley Catton.

Rye – AAFC

A versatile crop, rye grown in the Prairie region has numerous uses, including animal feed production, bread and cereal production and brewing and malting. Rye can also be used as a cover and forage crop. Like wheat, rye comes in winter and spring varieties, with winter rye remaining the most popular across Western Canada. In 2019, rye was grown over 114,100 hectares (281,700 acres) in the Prairies, producing 262,200 metric tonnes (289,000 US tons).

Various pest species target rye. Monitoring and scouting protocols as well as economic thresholds (when available) are found in Field Crop and Forage Pests and their Natural Enemies in Western Canada: Identification and Management and the Cutworm Pests of Crops on the Canadian Prairies: Identification and Management Field Guide. Additional monitoring protocols exist to control certain pests.

Rye field – AAFC
Rye Pests
  • Armyworm
  • Black grass bugs
  • Cereal leaf beetle
  • Darksided cutworm
  • Dingy cutworm
  • English green aphid
  • Fall armyworm
  • Fall field cricket
  • Glassy cutworm
  • Grasshoppers
  • Green-tan grass bugs
  • Breenbug
  • Pale western cutworm
  • Rice leaf bug
  • Variegated cutworm
  • Wheat head armyworm
  • Wheat midge
  • Wheat stem maggot
  • Wheat stem sawfly
  • Wireworms
Fall field cricket – Joseph Berger, bugwood.org, cc-by 3.0

ENTOMOLOGIST OF THE WEEK: HALEY CATTON

Name: Dr. Haley Catton
Affiliation: AAFC-Lethbridge Research and Development Centre
Contact Information: haley.catton@canada.ca
@haleycatton (Twitter)

How do you contribute in insect monitoring or surveillance on the Prairies?

My team and I often work on developing and refining monitoring methods for certain pests (e.g. wireworms). But, for the past few years we have actively been monitoring one particular tiny little insect – the parasitic wasp T. julis, a natural enemy of the cereal leaf beetle. These beneficial wasps are so small that they are easy to miss with the naked eye, only 2-3 mm long in their adult form! We track them by cutting open cereal leaf beetle larvae to see if they are parasitized. We can find 5-20 little T. julis larvae inside a single cereal leaf beetle larva! For next year, we ask that anyone on the Prairies who sees cereal leaf beetle larvae to send us a sample of 10-30 larvae so we can dissect them. We will tell you if T. julis is on the scene and contributing to management of this potentially damaging pest.

In your opinion, what is the most interesting field crop pest on the Prairies?

That’s tough to pick, all of them are interesting in their own way. But if I have to choose, it will be wireworm. This is a pest made up of several species, with long life spans, lots of host crops, and different behaviours. They can go without food for at least a year, and even moult to become smaller in times of stress. They are a formidable pest, but the more I learn about them, the more interesting the story becomes.

What is your favourite beneficial insect?

Another tough choice. T. julis is pretty spectacular, how it finds its host so effectively, a true “seek and destroy” biological control insect, or Field Hero. We think T. julis is a big reason why cereal leaf beetle has not become a major pest on the Prairies, but that is hard to prove when it is tough to even find larvae to dissect! This “disappearance” phenomenon is a big problem in biological control. When beneficial insects are very successful, the pests are no longer noticeable, and therefore less on people’s minds. The value of the beneficial insects therefore becomes “behind the scenes”, and can be overlooked. This is why more research and awareness are needed on the value and efficacy of beneficial insects, so they can considered and protected.

Tell us about an important/interesting project you are working on right now.

I’m just finishing up a 3-year project on wireworms (funded by AWC and WGRF), and have learned so much. I am working with a team to produce a wireworm field guide for the Prairies, and it is shaping up to be a really nice document. Expected release later this year!

What tools, platforms, etc. do you use to communicate with your stakeholders?

I love giving presentations, going to field days, and talking to farmers. Also, find me on Twitter (@haleycatton), or reach out by email, haley.catton@canada.ca.

Weekly Update

Greetings!

Week 16 and some interesting weather across the prairies!  Please bookmark the Blog or subscribe to receive the latest growing season information!

Please access the complete Weekly Update either as a series of Posts for Week 16 (July 25, 2019) OR a downloadable PDF. Be sure to check out the Insect of the Week – the rest of the growing season features doppelgangers to aid in-field scouting!

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

Subscribe to the Blog by following these easy steps!

Weather synopsis

Weather synopsis – Prairie temperatures continue to be cooler than average. This past week (July 15-21, 2019), temperatures were approximately 1 °C cooler than last week (Fig. 1). The warmest temperatures were observed across MB while temperatures were cooler in western SK and AB. 

Figure 1. Average temperature (°C) across the Canadian prairies the past seven days (July 15-21, 2019).
Figure 2. Average temperature (°C) across the Canadian prairies the past seven days (June 21-July 21, 2019).

Across the prairies, 30 day (June 21 – July 21, 2019) average temperatures have been approximately 1 °C cooler than normal (Fig. 3). Temperatures were warmest across MB and eastern SK. Growing season temperatures (April 1-July 21, 2019) have been 1 °C cooler than average; the warmest temperatures were observed across the southern prairies. 

Figure 3. Average temperature (°C) across the Canadian prairies for the growing season (April 1-July 21, 2019).

This past week significant rainfall amounts were reported the parkland region of  SK and AB (Fig. 4).  

Figure 4. Cumulative precipitation observed the past seven days across the Canadian prairies (July 15-21, 2019).
Figure 5. Cumulative precipitation observed the past 30 days across the Canadian prairies (June 21-July 21, 2019).

Across the prairies, rainfall amounts for the past 30 days have been highly variable (Fig. 7). Dryer conditions continue across southern AB. Rainfall was well above average in SK. Growing season (April 1 – July 21, 2019) rainfall amounts have been below average across southern regions of AB, and across MB. 

Figure 6. Cumulative precipitation observed the past 30 days across the Canadian prairies (April 1-July 21, 2019).
Figure 7. Percent of average precipitation observed across the Canadian prairies for the growing season (April 1-July 24, 2019).  
Image has not been reproduced in affiliation with, or with the endorsement of the Government of Canada and was retrieved (25Jul2019).  Access the full map at http://www.agr.gc.ca/DW-GS/current-actuelles.jspx?lang=eng&jsEnabled=true

The growing degree day map (GDD) (Base 5 ºC, April 1-July 21, 2019) is below (Fig. 8):

Figure 8. Growing degree day (Base 5 ºC) across the Canadian prairies for the growing season (April 1-July 21, 2019).

The growing degree day map (GDD) (Base 10 ºC, April 1-July 21, 2019) is below (Fig. 9):

Figure 9. Growing degree day (Base 10 ºC) across the Canadian prairies for the growing season (April 1-July 21, 2019).

The lowest temperatures (°C) observed the past seven days ranged from at least 14 down to at least 2 °C in the map below (Fig. 10).

Figure 10. Lowest temperatures (°C) observed across the Canadian prairies the past seven days (to July 21, 2019).  
Image has not been reproduced in affiliation with, or with the endorsement of the Government of Canada and was retrieved (25Jul2019).  Access the full map at http://www.agr.gc.ca/DW-GS/current-actuelles.jspx?lang=eng&jsEnabled=true

The highest temperatures (°C) observed the past seven days ranged from less than 16 up to at least 30 °C in the map below (Fig. 11).

Figure 11. Highest temperatures (°C) observed across the Canadian prairies the past seven days (to July 21, 2019).  
Image has not been reproduced in affiliation with, or with the endorsement of the Government of Canada and was retrieved (125ul2019).  Access the full map at http://www.agr.gc.ca/DW-GS/current-actuelles.jspx?lang=eng&jsEnabled=true

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

Wheat midge

Wheat Midge (Sitodiplosis mosellana) – Dry conditions in May and June have resulted in reduced emergence of adult populations across most of SK. Oviposition is well underway and larvae should be developing in wheat heads. Where wheat midge are present, the following maps indicate potential occurrence of eggs (Fig. 1) and larvae (present in wheat heads) across the prairies (Fig. 2). It should be noted that, based on fall surveys in 2018, wheat midge populations were expected to be low across most of AB and SK.

Figure 1. Predicted  potential occurrence of eggs laid by wheat midge (Sitodiplosis mosellana) across the Canadian prairies (as of July 21, 2019).
Figure 2. Predicted  potential occurrence of  larvae of wheat midge (Sitodiplosis mosellana) across the Canadian prairies (as of July 21, 2019).

Monitoring:
When monitoring wheat fields, pay attention to the synchrony between flying midge and anthesis.

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 (photographed by AAFC-Beav-S. Dufton & A. Jorgensen below). 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.

REMEMBER that in-field counts of wheat midge per head remain the basis of economic threshold decision.  Also remember that the parasitoid, Macroglenes penetrans (photographed by AAFC-Beav-S. Dufton 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.

Economic Thresholds for Wheat Midge:
a) To maintain optimum grade: 1 adult midge per 8 to 10 wheat heads during the susceptible stage.
b) 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. 

Wheat midge and its doppelganger, the lauxanid fly, were featured as the Insect of the Week (for Wk10).  Check that post for help with in-field scouting for this economic pest of wheat!  The differences between midges and parasitoid wasps are featured as the current Insect of the Week (for Wk11).  Not all flying insects are mosquitoes nor are they pests – many are important parasitoid wasps that actually regulate insect pest species in our field crops.

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

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

More information about Wheat midge can be found by accessing the pages from the new “Field Crop and Forage Pests and their Natural Enemies in Western Canada: Identification and Field Guide”.  View ONLY the Wheat midge pages but remember the guide is available as a free downloadable document as both an English-enhanced or French-enhanced version.

Predicted grasshopper development

Grasshopper Simulation Model Output – The grasshopper simulation model will be used to monitor grasshopper development across the prairies. Weekly temperature data collected across the prairies is incorporated into the simulation model which calculates estimates of grasshopper development stages based on biological parameters for Melanoplus sanguinipes (Migratory grasshopper).

Cool temperatures continue to result in reduced grasshopper developmental rates. Based on model runs, approximately 68% (50% last week) of the population should be in the 4th-5th instar and adult stages. Based on climate data, 80% of the population would be expected to be in the 4th-5th instar and adult stages. The following map indicates the average instar for grasshopper populations across the prairies (Fig. 1). Development is predicted to be greatest across southern MB and southeastern SK.

Figure 1. Predicted development stages of grasshopper (Melanoplus sanguinipes) populations across the Canadian prairies (as of July 21, 2019). 

The Insect of the Week’s Doppelganger featured GRASSHOPPERS for Week 14!!  Check out the excellent nymph photos to help your in-field scouting!

Biological and monitoring information related to grasshoppers in field crops is posted by Manitoba AgricultureSaskatchewan AgricultureAlberta Agriculture and Forestry, the BC Ministry of Agriculture and the Prairie Pest Monitoring Network.  Also refer to the grasshopper pages within the “Field Crop and Forage Pests and their Natural Enemies in Western Canada: Identification and management field guide” which is available as a free downloadable document in either an English-enhanced or French-enhanced version.

Bertha armyworm monitoring

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 AlbertaSaskatchewan (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 ManitobaSaskatchewanAlberta 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!

Lygus in canola

Lygus bugs (Lygus spp.) – Last week’s Insect of the Week’s doppelganger was lygus bug versus the alfalfa plant bug.  This week the doppelganger is lygus bug nymphs vs. aphids!  both include tips to to discern the difference between when doing in-field scouting!

The economic threshold for Lygus in canola is applied at late flower and early pod stages.  

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.

Scouting tips to keep in mind: 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.

Sampling becomes more representative IF repeated at multiple spots within a field.  For lygus bug monitoring, sampling is most accurate when repeated at a total of 15 spots within the field.  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).

Biological and monitoring information related to Lygus in field crops is posted by the provinces of Manitoba or Alberta fact sheets or the Prairie Pest Monitoring Network’s monitoring protocol.  Also refer to the Lygus pages within the new “Field Crop and Forage Pests and their Natural Enemies in Western Canada: Identification and management field guide” – both English or French versions are available.

West Nile Virus and Culex tarsalis

West Nile Virus Risk –  Health Canada posts information related to West Nile Virus in Canada.  Health Canada also tracks West Nile Virus through humanmosquitobird and horse surveillance.  Link here to access the most current weekly update (July 13, 2019). The screenshot below was retrieved 25Jul2019 as reference but access that information here.

The following is offered to predict when Culex tarsalis will begin to fly across the Canadian prairies (Fig. 1). Protect yourself by wearing DEET!  This week, regions most advanced in degree-day accumulations for Culex tarsalis, the vector for West Nile Virus, are shown in the map below.  Areas highlighted yellow in the map below (Fig. 2) are on the verge of approaching sufficient heat accumulation for mosquitoes to emerge.  Areas highlighted lime green should be preparing for C. tarsalis flight.

Figure 1. Predicted development of Culex tarsalis, across the Canadian prairies (as of July 21 2019).

Once adults emerge, the following map demonstrates how quickly a Culex tarsalis mosquito carrying WNV can become fully infective (i.e., when it has accumulated 109 base 14.3° degree days) – it’s a matter of days, depending on the region (Figure 2).

Provincial Insect Pest Reports

Provincial entomologists provide insect pest updates throughout the growing season so we link to their most recent information: 

Manitoba‘s Crop Pest Updates for 2019 are posted here. Access Issue #10 posted July 24, 2019 noting grasshoppers, cereal armyworms, and lygus bugs. There is a helpful photo of an European corn borer egg mass plus bertha armyworm pheromone trap counts, some of which are categaorized as “uncertain” so in-field scouting is critical.

Saskatchewan‘s Crops Blog Posts includes a segment on “Economic thresholds” by Kaeley Kindrachuk posted in May 2019. Also access the Crop Production News with Issue #5 (featuring pesticide drift information).

•  Alberta Agriculture and Forestry’s Agri-News includes an insect-related item in the July 8, 2019 edition with an important reminder that field scouting in July can lead to a more successful crop.

Crop report links

Crop reports are produced by:

The following crop reports are also available:

Field Events – Speak to an entomologist

Public summer field events – Coming to a field near you –  Prairie field crop entomologists are already scheduled to be at these 2019 field tour events from May-August (be sure to re-confirm dates and details as events are finalized):

•  August 8, 2019:  2019 Wheatstalk to be held at Teepee Creek AB.  View event info/registration details.   Entomologists tentatively participating: Jennifer Otani, Shelby Dufton, Amanda Jorgensen, Boyd Mori.

  August 8, 2019. Horticulture School. Agriculture and Agri-Food Canada Research Farm, Portage la Prairie, Manitoba. View event info/registration details.  Entomologist presenting: John Gavloski, Kyle Bobiwash.

Previous Posts

Click to review these earlier 2019 Posts:

2019 Risk and forecast maps – Week 2

Alfalfa weevil – Week 11

Bertha armyworm (predicted development) – Week 12

Cabbage seedpod weevil – Week 11
Cereal aphid manager APP – Week 12
Cereal leaf beetle – Week 9
Crop protection guides – Week 6
Cutworms – Week 5

Diamondback moth – Week 15

Field heroes – Week 6
Flea beetles – Week 5

Grasshoppers – Week 10

Insect scouting chart for Canola – Week 5
Insect scouting chart for Flax – Week 5

Monarch migration – Week 13

Painted lady butterfly – Week 8
Pea leaf weevil – Week 10
Prairie Crop Disease Monitoring Network – Week 11
Preparing grains for market – Week 15

Ticks and Lyme disease – Week 4
Timely IOTW to review – Week 13

Weather Radar – Week 6
Wildfires – Week 8

Wind trajectories – Review Page for list of PDFs for Weeks 1-12

Insect of the Week: Doppelgangers: Lygus bugs nymphs vs. aphids

The case of lygus bug nymphs versus aphids: Small, green, soft-bodied, sucking insects – at first glance they could be either lygus bug nymphs or aphids. But spend a moment and look for the following characteristics, and you’ll be able to tell which pest you are dealing with.

  • Size: depending on the species, aphids can reach up to 4 mm long, but most will be 1-2 mm. Lygus bug nymphs will be larger, 4-6 mm long
  • Cornicles (small upright backward-pointing tubes found on the back side at the rear of abdomen): aphids have them, lygus bug nymphs do not. In some aphid species, the cornicles or where they attach to the abdomen are black (e.g. corn aphid, English grain aphid).
  • Markings: older lygus bug nymphs have five distinct black dots on their thorax and abdomen; aphids do not.  

For more information about these species and more tips on telling them apart, see our Insect of the Week page! Also, see our Monitoring protocols for lygus bugs in canola

Tarnished plant bug nymph – note five black dots on thorax and abdomen – Scott Bauer, USDA
English grain aphid – adult and nymphs – note black cornicles (tubes) sticking out the back – Tyler Wist, AAFC

The case of the innocuous versus the evil twin: When making pest management decisions, be sure that the suspect is actually a pest. This can be challenge since insects often mimic each other or look very similar. An insect that looks, moves and acts like a pest may in fact be a look-alike or doppelganger.

Doppelgangers may be related (e.g. same genus) or may not be related, as in the case of monarch butterflies (Danaus plexippus) and viceroys (Limenitis achrippus).  Doppelgangers are  usually relatively harmless but sometimes the doppelganger is a pest yet their behaviour, lifecycle or hosts may be different.

Correctly identifying a pest enables selection of the most accurate scouting or monitoring protocol. Identification and monitoring enables the application of economic thresholds. It also enables a producer to select and apply the most effective control option(s) including method and timing of application.  For the rest of the growing season, the Insect of the Week will feature insect crop pests and their doppelgangers.

Review previously featured insects by visiting the Insect of the Week page.

Insect of the Week – Biological control agents of weeds

As we are nearing the end of the 2018 growing season, we decided to feature something a little bit different for this week’s Insect of the Week: insects that are biological control agents of weeds. Natural enemies of insects include parasitoids and predators that kill insect pests. Natural enemies of weeds include plant pathogens or insect herbivores that impact weed growth and reproduction, thus reducing reduce weed density. There are many insects that may be found in rangeland, forage and crop habitats that are biological control agents of weeds, some of which have been introduced purposely after rigorous testing for safety from places where our invasive plants have originated. Biological control agents of weeds act in two primary ways: plant herbivory and granivory. Plant herbivores consume root, leaves and./or shoots enough to typically reduce its ability to grow and reproduce, and thus its ability to compete with rangeland plants used in cattle grazing or with crops. Granivores or weed seed predators consume high numbers of weed seeds, thus reducing the number of viable weed seeds entering seed banks for germination in future growing seasons.

Ground beetles (Coleoptera: Carabidae) of several genera are known to eat weed seeds within crops, including Harpalus, Amara, Poecilus, and Pterostichus. The diets of some ground beetles almost entirely consist of weed seeds. Other ground beetles are primarily carnivores (i.e., generalist predators of other insects or slugs) that occasionally consume weed seeds. More information about the biology of ground beetles can be found by visiting the Insect of the Week page.

Mogulones crucifer (Pallas) is a biological control agent of hound’s-tongue (Cynoglossum officinale L.), a weedy pest of rangelands in southern British Columbia and southwestern Alberta. The adult stage of this weevil species (Coleoptera: Curculionidae) feeds on leaves of its host while the larvae consume the roots of the host plant. The weevil is highly mobile and has significantly reduced hound’s-tongue densities where it has been released for biological control. For more information about M. crucifer, visit https://www.for.gov.bc.ca/hra/plants/biocontrol/detailed_bioagent_pages/Mogulones_cruciger.htm

Prepared by Dr. Meghan Vankosky

Hound’s-tongue, an invasive species, is a host
plant for Mogulones crucifer
Photo: Jacob W. Frank
Mogulones crucifer adult on hound’s-tongue leaf
photo: Rosemarie De Clerk-Floate
Mogulones crucifer larvae infesting hound’s-tongue root
photo: Rosemarie De Clerk-Floate

Pre-Harvest Intervals

Reminder – Pre-Harvest Interval (PHI) – Growers with late-season insect pest problems must 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 strictly regulate and test for the presence of trace residues of pesticides.

An excellent summary of PHI for various pesticides in their various crops was posted by Saskatchewan Agriculture’s Danielle Stephens in 2016 within their Crop Production News.

In 2013, the Canola Council of Canada created and circulated their “Spray to Swath Interval Calculator” 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.  

Finally, work towards “Keeping It Clean” so your grain is ready for export!  More information about PHI and Maximum Residue Limits (MRL) is available on the Keeping It Clean site. 

Slugs on wheat

Earlier this month, feeding channels on the upper surfaces of the flag leaf in wheat were reported and evening scouting revealed this culprit!

Figure 1. Deroceras reticulatum, the “grey field slug”, on wheat growing near Crooked Creek AB (August 2, 2018; det. Lien Luong).
Figure 2.  Flag leaf feeding damage  on wheat caused by the grey field slug (Deroceras reticulatum). 
Photo taken near Crooked Creek AB on August 2, 2018, by J. Otani.

Field scouting was performed in the evening from 8:30-10:30pm.  As the temperatures decreased, the slugs moved up the wheat stems, climbing to the topside of the flag leaf and onto the wheat heads although they did not appear to feed at the developing kernels.   Wheat was hand-collected by clipping stems ~20cm above the ground to later reveal a density of 1.04 slugs per stem (n=465 stems) causing the above damage (Fig. 2). 

Specimens were forwarded to L. Luong (U of A) who identified the slugs from the above field as one species, Deroceras reticulatum, the grey field slug.  The majority were juveniles. The grey field slug is the most common to occur in the home garden.

Thanks to Dr. John Gavloski (Manitoba Agriculture) who prepared the following in relation to slugs in field crops: 

  • Slugs are a complicated problem because most general insecticides don’t work well on them.  
  • Sluggo Professional (PCP#30025) is registered for slugs in field crops. It is a bait, which must be consumed by the slugs to be effective but it could be expensive on a large field.  
  • Often insecticides don’t work well on slugs and it may be related to the mucous coating slugs exude.  
  • Be wary, if an insecticide is applied, the product will likely not affect the slugs but it will kill the ground beetles and other natural enemies that prey upon or parasitize slugs and could exacerbate the slug problem.  
  • Growers using no-till or minimum till operations may consider tillage to help reduce future levels of slugs.  

Health Canada has an overview of snails relating to gardening posted here.

Plant bugs

Bugs of the Family Miridae are also referred to by their common name, “plant bugs”. Prairie growers are familiar with two plant bugs – lygus and alfalfa plant bugs.  

Plant bugs are a very large group of bugs that can include herbivores, omnivores and predators but virtually all are polyphagous which is a term referring to their ability to feed on several species, even Families of other organisms.  Plant bugs are generally very mobile as both adults and nymphs and move readily to feed on different host plants as the season progresses.  Plant bugs can also have different lifecycles with alfalfa plant bugs reproducing as one generation per year whereas lygus bugs can have two to three generations per year.

This season in southern Alberta, first-generation lygus bugs damaged seed alfalfa in June then the second generation damaged canola fields in July and August. High numbers of lygus bugs (10-20 per sweep and higher) were collected in research and demonstration plots of sainfoin, hemp and quinoa in southern Alberta.  

Both lygus and alfalfa plant bugs have sucking mouthparts and the larger, more mature nymphs plus adults are able to penetrate and extract oils from seeds, causing them to shrivel and lose in quality.  Plant bugs feeding in faba beans can cause spotting.

Wasps in the genus Peristenus include native species that attack lygus and alfalfa plant bugs but normally don’t occur in sufficient densities to reduce outbreaking populations of these plant bugs.  The exotic Peristenus digoneutis from Europe, if it could be established and is shown not to interfere with native predators and parasitoids, may increase parasitism to help prevent plant bug outbreaks.  

Adult L. lineolaris (5-6 mm long) (photo: AAFC-Saskatoon).
Fifth instar lygus bug nymph (3-4 mm long) (photo:  AAFC-Saskatoon).

Weekly Update

Greetings!

This is the last Weekly Update of the 2018 growing season. It is the 16th week of both the INSECT OF THE WEEK plus WEEKLY UPDATE – hopefully each has supported in-field scouting in our prairie field crops! 

Thank you to our many contributors and sincere appreciation is extended to the many people who repeatedly visited fields all season to support provincial AND prairie-wide insect pest monitoring in field crops in 2018!  

Access the complete Weekly Update either as a series of Posts for Week 16 (August 23, 2018) OR a downloadable PDF version.  Also review the “Insect of the Week” for Week 16!

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

Subscribe to the Blog by following these three steps!

Weather synopsis

Weather synopsis – We close out the Weekly Update for the growing season by looking back at precipitation thanks to the AAFC Drought Watch folks.

This is a map of growing season precipitation (% of normal; Fig. 1):

Figure 1.  Percent of normal precipitation for the growing season (April 1-August 22, 2018) across the Canadian prairies. Image has not been reproduced in affiliation with, or with the endorsement of the Government of Canada and was retrieved (23Aug2018).  Access the full map at http://www.agr.gc.ca/DW-GS/current-actuelles.jspx?lang=eng&jsEnabled=true

The following map illustrates precipitation (% of normal) for the last 60 days (Fig. 2):

Figure 2. Percent of normal precipitation the past 60 days (as of August 22, 2018) across the Canadian prairies.
Image has not been reproduced in affiliation with, or with the endorsement of the Government of Canada and was retrieved (23Aug2018).  Access the full map at http://www.agr.gc.ca/DW-GS/current-actuelles.jspx?lang=eng&jsEnabled=true

Whereas this is the precipitation (% of normal) for the past 30 days (Fig. 3):

Figure 3. Percent of normal precipitation the past 30 days (as of August 22, 2018) across the Canadian prairies.
Image has not been reproduced in affiliation with, or with the endorsement of the Government of Canada and was retrieved (23Aug2018).  Access the full map at http://www.agr.gc.ca/DW-GS/current-actuelles.jspx?lang=eng&jsEnabled=true

Here is the accumulated precipitation the past 7 days (Fig. 4)!

Figure 4. Accumulated precipitation the past 7 days (as of August 22, 2018) across the Canadian prairies.
Image has not been reproduced in affiliation with, or with the endorsement of the Government of Canada and was retrieved (23Aug2018).  Access the full map at http://www.agr.gc.ca/DW-GS/current-actuelles.jspx?lang=eng&jsEnabled=true

The map below reflects the Highest Temperatures occurring over the past 7 days (August 16-22, 2018) across the prairies and is available from Agriculture and Agri-Food Canada (Fig. 5). 

Figure 5. Highest temperature across the Canadian prairies the past seven days (August 16-22, 2018). Image has not been reproduced in affiliation with, or with the endorsement of the Government of Canada and was retrieved (23Aug2018).  Access the full map at http://www.agr.gc.ca/DW-GS/current-actuelles.jspx?lang=eng&jsEnabled=true

 The map below reflects the Highest Temperatures occurring over the past 7 days (August 16-22, 2018) across the prairies and is available from Agriculture and Agri-Food Canada (Fig. 6). 

Figure 6. Lowest temperature across the Canadian prairies the past seven days (August 16-22, 2018). Image has not been reproduced in affiliation with, or with the endorsement of the Government of Canada and was retrieved (23Aug2018).  Access the full map at http://www.agr.gc.ca/DW-GS/current-actuelles.jspx?lang=eng&jsEnabled=true

Normally we share growing degree day maps calculated for the growing season including  March 1, 2018, to the present.  This week we instead reference the AAFC Drought Watch maps.  Below is the growing degree day map (GDD: Base 10ºC for APRIL 1 – August 20, 2018) and is available from Agriculture and Agri-Food Canada (Fig. 7):

Figure 7. Growing degree-day using base 10ºC for across the Canadian prairies for the growing season (APRIL 1-August 20, 2018). Image has not been reproduced in affiliation with, or with the endorsement of the Government of Canada and was retrieved (23Aug2018).  Access the full map at http://www.agr.gc.ca/DW-GS/current-actuelles.jspx?lang=eng&jsEnabled=true

Below is the growing degree day map (GDD: Base 5ºC for APRIL 1 – August 20, 2018) and is available from Agriculture and Agri-Food Canada (Fig. 8):

Figure 8. Growing degree-day using base 5ºC for across the Canadian prairies for the growing season (APRIL 1-August 20, 2018). Image has not been reproduced in affiliation with, or with the endorsement of the Government of Canada and was retrieved (23Aug2018).  Access the full map at http://www.agr.gc.ca/DW-GS/current-actuelles.jspx?lang=eng&jsEnabled=true

The maps above are all produced by Agriculture and Agri-Food Canada.  Growers can bookmark the AAFC Drought Watch Maps to continue to follow weather conditions during harvest and beyond.

Harvest Sample Program

The Canadian Grain Commission is ready to grade grain samples harvested in 2018.  Samples are accepted up to November but send samples as soon a harvest is complete.

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.  The data collected also helps Canada market its grain to the world!

More information on the Harvest Sample Program is available at the Canadian Grain Commission’s website where growers can register online to receive a kit to submit their grain.  

In exchange for your samples, the CGC assesses and provides the following unofficial results FOR FREE:

  • dockage assessment on canola
  • unofficial grade
  • protein content on barley, beans, chick peas, lentils, oats, peas and wheat
  • oil, protein and chlorophyll content for canola
  • oil and protein content and iodine value for flaxseed
  • oil and protein for mustard seed and soybean
  • NEW for 2018-19: Participants will receive Falling Number and deoxynivalenol (DON) results for their wheat samples at no cost. This enhancement to the Harvest Sample Program is the first initiative to be funded by the Canadian Grain Commission’s accumulated surplus.

Many producers find having both grade and quality information on their samples before delivering their grain to be helpful.

Stored Product Pests

The Canadian Grain Commission’s website has an online key to stored product pests.  Growers managing grain storage can find an online identification tool for stored product pests (e.g., Rusty grain beetleRed flour beetleConfused flour beetleSaw-toothed grain beetle, and more).  The online tool features excellent diagnostic photos.  A screen shot of the webpage is included below for reference.

Provincial Insect Pest Reports

Provincial entomologists provide insect pest updates throughout the growing season so we link to their most recent information: 

Manitoba‘s Insect and Disease Updates for 2018 can be accessed here. Issue #13 (posted August 22, 2018).

Saskatchewan‘s Crop Production News for 2018 is posted with Issue #7 now available. This issue includes an update from the Crop Protection Lab.

Alberta Agriculture and Forestry’s Call of the Land regularly includes insect pest updates from Scott Meers. The most recent Call of the Land was posted August 23, 2018.

Crop reports

Crop reports are produced by:

The following crop reports are also available:

Previous Posts

The following is a list of 2018 Posts – click to review:

Abundant parasitoids in canola – Week 10 
Alfalfa weevil – Week 6
Aphid App – Week 12

Bertha armyworm – Week 15

Cabbage seedpod weevil – Week 12 
Cabbage root maggot – Week 11 
Cereal aphid manager (CAM) – Week 2
Cereal leaf beetle – Week 13
Cereal leaf beetle larvae request – Week 8
Crop protection guides – Week 2
Cutworms – Week 4

Diamondback moth – Week 7
Download the field guide – Week 10

Field heroes – Week 8
Flea beetles – Week 4
Flea beetles – Week 15

Grasshopper simulation model output – Week 13

Ladybird beetles – Week 15
Lygus in canola – Week 15

Monarch migration – Week 8

Pea leaf weevil – Week 13

PMRA Pesticide Label Mobile App – Week 4

Scouting charts (canola and flax) – Week 3

Thrips – Week 15
Ticks and Lyme Disease – Week 4

Weather radar – Week 3
West nile virus risk – Week 13
Wheat midge – Week 12

White grubs in fields – Week 8

Wind trajectories – Week 6

Wireworm distribution maps – Week 6

Review the 2018 INSECT OF THE WEEK!

Need a refresher or simply want to keep our 2018 lineup a click away? Here’s the 2018 INSECT OF THE WEEK lineup for the growing season:

Wk01 (May 07, 2018) – Glassy cutworm
Wk02 (May 14, 2018) – Darksided cutworm
Wk03 (21 May, 2018) – Ground beetles: cutworm natural enemies
Wk04 (May 28, 2018) – Flea Beetles
Wk05 (June 4, 2018) – Wireworms
Wk06 (June 11, 2018)Pterostichus melanarius
Wk07 (June 18, 2018) – Red turnip beetle
Wk08 (June 25, 2018) – Bruner grasshopper
Wk09 (July 03, 2018) – Pea aphid (Hemiptera: Aphididae) 
Wk10 (July 09, 2018) – Natural enemies of pea aphids
Wk11 (July 16, 2018) – The new canola flower midge
Wk12 (July 23, 2018) – Natural enemies of the canola flower midge
Wk13 (July 30, 2018) – Wheat stem sawfly (Cephus cinctus, Hymenoptera: Cephidae)
Wk14 (Aug 07, 2018) – Natural Enemies of the wheat stem sawfly
Extra (Aug 10, 2018) – English grain aphid (Hemiptera: Aphididae)
Wk 15 (Aug 13, 2018) – Twospotted spider mite (Acarina: Tetranychus)
Wk16 (August 20, 2018) – Biological control agents of weeds

Review the WEEKLY UPDATE for 2018 growing season!

Access the WEEKLY UPDATE as either a series of Posts OR downloadable PDF file for the entire 2018 growing season: 

Wk01 – May 10, 2018
Wk02 – May 17, 2018
Wk03 – May 24, 2018
Wk04 – May 31, 2018
Wk05 – Jun 07, 2018
Wk06 – Jun 14, 2018
Wk07 – Jun 21, 2018
Wk08 – Jun 28, 2018
Wk09 – Jul 05, 2018
Wk10 – Jul 12, 2018
Wk11 – Jul 19, 2018
Wk12 – Jul 26, 2018
Wk13 – Aug 02, 2018
Wk14 – Aug 09, 2018
Wk15 – Aug 16, 2018
Wk16 – Aug 23, 2018

Upcoming Meetings and Conferences

Upcoming Meetings and Conferences – The following agricultural insect pest-related meetings and conferences will be held – be sure to re-confirm dates and details as events are finalized:

  • September 27-29, 2018:  The Entomological Society of Alberta Annual Meeting will be held at Edmonton AB and information is available here.
  • October 18, 2018:  The Western Committee on Crop Pests will meet at Lloydminster SK and information is available here.  
  • October 23-25, 2018:  The 11th Canadian Pulse Research Workshop will be held at Edmonton.  More information is available here.  
  • October 23-25, 2018:  The 2018 Canola Discovery Forum will be held at Banff AB.  More information is available here.  
  • November 11-14, 2018:  The Joint Annual Meeting of the Entomological Society of Canada, Entomological Society of America and Entomological Society of British Columbia meets at Vancouver BCand information is available here
  • January 15-16, 2019:  CropSphere Agricultural Conference will be held at TCU Place in Saskatoon SK during Crop Production Week.  More information is available at: https://www.cropsphere.com/index.cfm 
  • January 22-24, 2019: The Manitoba Ag Days show will be held at the Keystone Centre in Brandon MB. More information will be available at: https://www.agdays.com/show-info/
  • January 29-31, 2019:  FarmTech 2019 will be held in Edmonton AB and information is available at http://farmtechconference.com/  with registration typically opening early in November.

Please send other IPM-related conference and meetings to jennifer.otani@canada.ca to update this information.

Provincial Insect Pest Reports

Provincial entomologists provide insect pest updates throughout the growing season so we have attempted to link to their most recent information: 


● Manitoba’s Insect and Disease Update for 2017 is prepared by John Gavloski and Pratisara Bajracharya and read Issue #13 (posted August 16, 2017) noting soybean aphids as field near the R6 stage and high levels of bertha armyworm larvae from some fields in western Manitoba.

● Saskatchewan’s Crop Production News – 2017 – Issue #5 includes information related to value of late-season disease scouting and record keeping, critical periods for crop water use, and leaving tall-stubble at harvest.

● Watch for Alberta Agriculture and Forestry’s Call of the Land and access the most recent Insect Update (August 17, 2017) provided by Scott Meers. That report notes that diamondback moth are starting to pupate in central and southern fields in the province yet late canola may still need monitoring for DBM larvae, bedstraw hawkmoth larvae (~2.5″ long) have been spotted in canola feeding on volunteer cleavers, the beginning of post-harvest survey for wheat midge and wheat stem sawfly across the province, plus the Agricultural Fieldmen are now ~30% completed the annual grasshopper survey with data coming in already.

Crop reports

Crop reports are produced by:
• Manitoba Agriculture, Rural Development (August 14, 2017)
• Saskatchewan Agriculture Crop Report (August 8-14, 2017)

• Alberta Agriculture and Forestry Crop Report (August 8, 2017)


West Nile Virus and Culex tarsalis

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.  As of August 13 2017areas highlighted in red on the map below have accumulated sufficient heat for C. tarsalis to fly.  Areas highlighted in red, orange and even yellow will have C. tarsalis flying so wear your DEET to stay protected!




The Public Health Agency of Canada posts information related to West Nile Virus in Canada.  In 2016, 104 human clinical cases of West Nile Virus were reported.  The map of clinical cases of West Nile Virus in Canada in 2017 is updated through the summer and three cases of viral West Nile have been reported so far (as of August 5, 2017).  All cases were reported from Ontario (in Timiskaming and Windsor-Essex).

The Canadian Wildlife Health Cooperative compiles and posts information related to their disease surveillance for West Nile Virus in birds.  As of August 17, 2017, 1113 birds were examined and 48 have tested positive for West Nile virus; one from Saskatchewan, two from Manitoba, 13 from Ontario, and 32 from Quebec.

The Public Health Agency of Canada also monitors and posts updates on the status of WNV in Mosquitoes.  As of July 22, 2017, Quebec, Ontario, Manitoba and Saskatchewan have reports of positive mosquito pools of West Nile Virus.  A total of 47 positive mosquito pools have been found: 

  • 33 from Ontario [Peel Regional (5), Toronto (6), Halton(5), Haliburton-Kwartha-Pine Ridge District(1), Simcoe Muskoka District (1), Windsor-Essex County (6), Eastern Ontario (1), Durham Reginal (1), Hamilton (1), Haliburton-Kawarta-Pine Ridge district (1), Hastings and Prince Edward Countries (2), and York Regional (3)];  
  • 11 from Manitoba [(Winnipeg (3), Southern (2), Interlake eastern (1), and Prairie Mountain(5)]; 
  • 2 from Quebec [Montérégie (1), Laval (1)], and 
  • 1 from Saskatchewan. 

Insect of the Week – Bronzed blossom pollen beetle

This week’s Insect of the Week is the bronzed blossom pollen beetle. They feed on canola and oilseed rape, mustards, bittercress, rockcress, wild radish and dogmustard. They are not known to be established in Western Canada, but are present in Nova Scotia, PEI and Quebec. Adult females lay clusters of 2 to 3 eggs in developing buds and can lay up to 250 eggs in one summer. Once the eggs hatch, larva enter developing flower buds to feed. This feeding can reduce seed production by up to 70%!

For more information on the bronzed blossom pollen beetle, see our Insect of the Week page.

Bronzed blossom pollen beetle – adults (C. Noronha, AAFC)
Bronzed blossom pollen beetle – eggs (C. Noronha, AAFC)



Remember the NEW Cutworm Field Guide is free and downloadable in 2017!

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Weekly Update – Greetings!

Greetings!

Please access the Weekly Update for August 17, 2017 (Week 16), as either a series of Posts  or a downloadable PDF.   


Questions or problems accessing the contents of this Weekly Update?  Please e-mail either Dr. Owen Olfert or Jennifer Otani.  Past “Weekly Updates” can be accessed on our Weekly Update page.

Subscribe to the Blog by following these three steps!

Weekly Update – Weather Synopsis

Weather synopsis – Temperature – This week’s temperatures were warmest in southern Alberta and Manitoba (Fig. 1). The 30-day average temperatures were warmest along the border with USA (Fig. 2).

Figure 1. Average precipitation across the Canadian prairies the past
seven days (August 7-14, 2017).



Figure 2.  Average temperature across the Canadian prairies the
past 30 days (July 14-August 14, 2017).





After a fair bit heat across the prairies (Fig. 3), a few of us woke to cooler temperatures (Fig. 4) this week!

Figure 3.  Highest temperatures the past seven days (August  10-16, 2017) across
the Canadian prairies.
Figure 4.  Lowest temperatures the past seven days (August  10-16, 2017) across
the Canadian prairies.



Precipitation – Seven-day rainfall accumulations were greatest in regions north of the Yellowhead highway (Fig. 5). Total 30-day rainfall accumulations indicate that conditions dryer than normal for most of the prairies, particularly southern and central regions of Alberta (Fig. 6). 

Figure 5. Accumulated precipitation the past seven days (August 7-13, 2017).



Figure 6. Percent of average precipitation across the Canadian prairies the 
past 30 days (July 15-August 13, 2017). 



This growing season (April 1 – August 13, 2017), the percent of average precipitation continues to be below average for most of the prairies (Fig. 7).

Figure 7. Percent of average precipitation across the Canadian prairies for the 
growing season (April 1-August 13, 2017). 






The growing degree day map (GDD) (Base 10ºC, March 1 – August 13, 2017) is below:






The growing degree day map (GDD) (Base 5ºC, March 1 – August 13, 2017) is below:







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

Weekly Update – Pre-Harvest Intervals (PHI)

Pre-Harvest Interval (PHI) – Growers with 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 strictly regulate and test for the presence of trace residues of pesticides.

An excellent summary of PHI for various pesticides in their various crops was posted by Saskatchewan Agriculture’s Danielle Stephens in 2016 within their Crop Production News.


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.  More information about PHI and Maximum Residue Limits (MRL) is available on the Canola Council of Canada’s website.


Weekly Update – Crop protection guides

Crop Protection Guides – If you don’t have a copy of your province’s Crop Protection Guide, please make use of these links to access:
• Saskatchewan’s Crop Protection Guide
• Manitoba’s Guide to Crop Protection Guide 
• Alberta’s Crop Protection or Blue Book 
• Western Committee on Crop Pests Guidelines for the Control of Crop Pests


Recall earlier this spring that Health Canada’s Pest Management Regulatory Agency launched a new mobile app to access pesticide labels registered for use in Canada. The App helps homeowners, farmers, industry, provincial and federal organizations access details for pest control products from a smartphone or tablet.  Download it as either:

Weekly Update – Diamondback moth

Diamondback moth (Plutellidae: Plutella xylostella) – Based on Harcourt (1954), this week the DBM model was run with a biofix date of May 21. The following map illustrates that potentially three generations (after the migratory population) may have been completed across most of the prairies. 



REMINDER – Once 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 (Fig. 1) dislodged from the plant. Repeat this procedure at least in five locations in the field to get an accurate count.  The economic threshold for diamondback moth in canola at the advanced pod stage is 20 to 30 larvae/ 0.1  (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  (approximately 1-2 larvae per plant).


Figure 1. Diamondback larva measuring ~8mm long.
Note brown head capsule and forked appearance of prolegs on posterior.


Figure 2. Diamondback moth pupa within silken cocoon.


Biological and monitoring information for DBM is posted by Manitoba Agriculture, Food and Rural DevelopmentSaskatchewan AgricultureAlberta Agriculture and Forestry, and the Prairie Pest Monitoring Network.  

More information about Diamondback moths can be found by accessing the pages from the new “Field Crop and Forage Pests and their Natural Enemies in Western Canada: Identification and Field Guide”.  View ONLY the Diamondback moth page but remember the guide is available as a free downloadable document as both an English-enhanced or French-enhanced version.


Figure 3. Diamondback moth.


Across the prairies, provincial staff coordinate diamondback pheromone trapping during the growing season:

● Low numbers of moths have been reported across Saskatchewan for the 2017 pheromone monitoring.  
● Manitoba Agriculture and Rural Initiatives posted low DBM counts which can be reviewed here.  
● Alberta Agriculture and Forestry has a live 2017 map reporting Diamondback moth pheromone trap interceptions.  A copy of the map (retrieved July 20, 2017) is below for reference.

Weekly Update – Bertha Armyworm

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 ManitobaSaskatchewan and Alberta.



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:  


Biological and monitoring information related to bertha armyworm in field crops is posted by the provinces of ManitobaSaskatchewanAlberta and the Prairie Pest Monitoring Network.  Also refer to the bertha armyworm pages within the new “Field Crop and Forage Pests and their Natural Enemies in Western Canada: Identification and management field guide” – both English-enhanced or French-enhanced versions are available.

Weekly Update – Lygus in canola

Lygus bugs (Lygus spp.) – Reminder – The economic threshold for Lygus in canola is applied at late flower and early pod stages.  

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).


Biological and monitoring information related to Lygus in field crops is posted by the provinces of Manitoba or Alberta fact sheets or the Prairie Pest Monitoring Network’s monitoring protocol.  Also refer to the Lygus pages within the new “Field Crop and Forage Pests and their Natural Enemies in Western Canada: Identification and management field guide” – both English-enhanced or French-enhanced versions are available.

Weekly Update – Predicted Grasshopper Development

Grasshopper Simulation Model Output – Based on model output, grasshopper development is slightly ahead of long term averages with approximately 80% of the population in the adult stage.  The following map presents model data for oviposition. Given the warm conditions across the southern prairies, it is not surprising that oviposition rates are predicted to be greatest in southern Alberta and in south-central Saskatchewan.



Grasshopper scouting steps can be reviewed in the previous Week 13 Post.


Reminder:  Biological and monitoring information related to grasshoppers in field crops is posted by Manitoba Agriculture, Food and Rural DevelopmentSaskatchewan AgricultureAlberta Agriculture and Forestry, the BC Ministry of Agriculture and the Prairie Pest Monitoring Network.  Also refer to the grasshopper pages within the new “Field Crop and Forage Pests and their Natural Enemies in Western Canada: Identification and management field guide” as an English-enhanced or French-enhanced version.

Weekly Update – Time of Swathing for Canola

The Canola Council of Canada created a guide to help growers estimate swathing time in canola.  A screen shot of the downloadable Canola Swathing Guide has been included below for reference.




Weekly Update – Wheat surveying (post-harvest)

Wheat surveying  As wheat is harvested, monitoring can begin for two wheat pests including wheat midge and wheat stem sawfly.  As soon as the combine passes through, in-field monitoring can commence with:
Soil core sampling is used to assess the densities of wheat midge cocoons set to overwinter, PLUS
● The number of cut stems can be counted to determine the density of wheat stem sawfly.

By January, forecast and risk maps summarizing surveying efforts for the above pests will be available (e.g., check the Risk Map Page).


More information about these pests can be found by accessing the pages from the new “Field Crop and Forage Pests and their Natural Enemies in Western Canada: Identification and Field Guide”.  View ONLY the Wheat midge pages or ONLY the Wheat stem sawfly pages.  Remember the entire guide is available as a free downloadable document as both an English-enhanced or French-enhanced version.

Information related to wheat midge biology and monitoring can be accessed by linking to your provincial fact sheet (Saskatchewan Agriculture or Alberta Agriculture & Forestry) or the PPMN protocol


Information related to wheat stem sawfly is posted by Alberta Agriculture & Forestry, Saskatchewan Agriculture, Manitoba Agriculture, or the PPMN

It’s all about the habitat – The secret life of cattle dung!

Cattle dung provides moisture, nutrients, and shelter for numerous insect species and other arthropods.  Ralf Jochmann’s video magnificently captures some of this diversity, using close-up photography and narration (https://www.youtube.com/watch?v=-l05EHZMmKE).



Adults of the dung beetle Chilothorax (Aphodius) distinctus are common in cattle dung, particularly in September and early October.  Larvae develop in agricultural soils where they can occasionally cause crop damage when present in high densities.  For more information on this occasional pest, click here.

Weekly Update – Previous Posts

The following is a list of 2017 Posts – click to review:

Alfalfa Weevil (Week 11)


Brood X Cicadas


Cabbage seedpod weevil (Week 12)

Canola scouting chart
Cereal leaf beetle
Crickets with your popcorn
Cutworms

Diamondback moth (Week 14)


Flax scouting chart

Flea beetles

Grasshoppers (Week 13)

Iceberg reports

Insects as food (Week 14)

Lily leaf beetle


Monarch migration (Week 10)


Painted lady butterflies (Week 9)

Pea leaf weevil
PMRA Pesticide Label Mobile App

Nysius niger (Week 8)


Ticks and Lyme disease


Weather radar

Wheat midge
White grubs in fields (Week 9)
Wildfires (Week 13)

Wind trajectories

Weekly Update (UPDATED!)

Greetings!

Three sections of the Weekly Update for Week 16 (August 17, 2016) were just updated!  A downloadable PDF copy of the updated Weekly Update can now be accessed here.  

Subscribe to the Blog by following the instructions posted here!  You can receive automatic updates in your inbox through the growing season.



Questions or problems accessing the contents of this Weekly Update?  Please e-mail either Dr. Owen Olfert or Jennifer Otani.  Past “Weekly Updates” are very kindly archived to the Western Forum website by webmaster, Dr. Kelly Turkington.  

Weekly Update – Weather Synopsis (updated)

Weather synopsis – The average temperature over the past seven days (August 7-14, 2016) was similar to Long Term Normal (LTN) values.



Across central Alberta, Saskatchewan, and Manitoba,  average cumulative rainfall was well above LTN values.





The average 30 day temperature for July 8-August 7, 2016, was similar to LTN and rainfall was 50% greater than LTN (average across the prairies). The wettest conditions have been in south and central areas of western Saskatchewan and central Alberta.






The average growing season temperature (April 1- August 7, 2016) was marginally warmer than normal. Growing season rainfall has been approximately 28% above average.






The map below shows the modelled soil moisture across the prairies (August 14, 2016).



The updated growing degree day map (GDD) (Base 5ºC, March 1 – August 14, 2016) is below:






While the growing degree day map (GDD) (Base 10ºC, March 1 – August 14, 2016) is below:







The map below shows the Lowest Temperatures the Past 7 Days (August 10 – August 16, 2016) across the prairies:


The map below shows the Highest Temperatures the Past 7 Days (August 10 – August 16, 2016):




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

Weekly Update – Swede midge (updated)

Swede midge (Contarinia nasturtiiThis growing season, bioclimatic model outputs predicting swede midge development continue to be compared to in-field observations of actual midge in canola in Saskatchewan since the model has yet to be validated with midge data from that region.


The model was run for Melfort SK for April 1 – 14 and the output suggests 4 generations might possibly occur in 2016 in northeast Saskatchewan.


Warm, wet conditions are predicted to result in shorter generation times in July and August than May and June.





In-field monitoring continues to be the priority both to detect new populations of swede midge on the prairies but then to validate the number of generations and phenology of this pest relative to canola development on the prairies.    

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.
• 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.
• Young plants that show unusual growth habits should be examined carefully for damage and 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.
• Refer to the Canola Watch article by Dr. Julie Soroka for more information on swede midge and watch for a new Ontario fact sheet produced by Baute et al. 2016.


Weekly Update – Grasshoppers (Updated)

Grasshoppers (Acrididae) – Across the prairies the model indicates that 80% of the population should be in the adult stage. This is approximately 10% greater than average. Oviposition is predicted to be well underway and is most advanced in Manitoba and southeast Saskatchewan.  




In central Saskatchewan, grasshopper development is slightly ahead of average development. The following graph shows predicted grasshopper development at Saskatoon for August 7, 2016. The model indicates that oviposition is well underway.  


Melanopline development for Saskatoon (August 12, 2016) was 5.6. The most abundant species was M. dawsoni (40%), followed by M. bivittatus (21.6%).





Biological and monitoring information related to grasshoppers in field crops is posted by the provinces of ManitobaSaskatchewanAlbertaBritish Columbia and the Prairie Pest Monitoring Network.  Also refer to the grasshopper pages within the new “Field Crop and Forage Pests and their Natural Enemies in Western Canada: Identification and management field guide” – both English-enhanced or French-enhanced versions are available.

Weekly Update

Greetings!

A downloadable PDF version of the complete Weekly Update for Week 16 (August 17, 2016) can be accessed here.  

This edition includes the “Insect of the Week” featuring beneficial arthropods in 2016!

Subscribe to the Blog by following the instructions posted here!  You can receive automatic updates in your inbox through the growing season.



Questions or problems accessing the contents of this Weekly Update?  Please e-mail either Dr. Owen Olfert or Jennifer Otani.  Past “Weekly Updates” are very kindly archived to the Western Forum website by webmaster, Dr. Kelly Turkington.  

Weekly Update – Weather Synopsis

Weather synopsis – This Post has been updated!  Please view the new Post here!

Weekly Update – Pre-Harvest Intervals (PHI)

Pre-Harvest Interval (PHI) -Reminder – Growers with 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 strictly regulate and test for the presence of trace residues of pesticides.

An excellent summary of PHI for various pesticides in their various crops was posted by Saskatchewan Agriculture this week within their Crop Production News.


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.  More information about PHI and Maximum Residue Limits (MRL) is available on the Canola Council of Canada’s website.

Weekly Update – Swede midge

Swede midge (Contarinia nasturtii– This post has been updated!  Please view the new Post here.

Weekly Update – Grasshoppers

Grasshoppers (Acrididae) – This post has been updated!  Please view it here!

Weekly Update – West Nile Virus and Culex tarsalis

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.  As of August 14, 2016areas highlighted in yellow, orange, or red on the map below have accumulated sufficient heat for C. tarsalis to fly so wear your DEET to stay protected!


The Public Health Agency of Canada posts information related to West Nile Virus in Canada.  The map of clinical cases of West Nile Virus in Canada in 2016 is posted (as of July 23, 2016) while a screen shot is provided below (retrieved August 17, 2016).

WN Cases Canada.jpg

The Canadian Wildlife Health Cooperative compiles and posts information related to their disease surveillance for West Nile Virus.  As of August 17, 2016, 32 birds were submitted for testing yet none have tested positive for West Nile virus. 

Provincial Insect Pest Reports

Provincial entomologists provide insect pest updates throughout the growing season so we have attempted to link to their most recent information: 


Manitoba’s Insect and Disease Update which includes lygus in canola, notes the occurance of small insect larvae on sclerotinia-infected areas of canola, soybean and dry beans AND includes a call for grasshopper surveying in August (August 17, 2016, prepared by John Gavloski and Pratisara Bajracharya).

Saskatchewan’s Crop Production News includes an update on West Nile disease in Saskatchewan in Issue 7prepared by Scott Hartley.  The report notes, “For the week of August 6, 2016, Saskatchewan Health reported that numbers of Culex tarsalis continue to rise in southern and central Saskatchewan. The risk of West Nile Virus transmission to humans remains at a moderate level in southern Saskatchewan, but increasing numbers of infected mosquitoes have been found this past week.”


Watch for Alberta Agriculture and Forestry’s Call of the Land for updates from Scott Meers who recently provided an update (posted on August 4, 2016). The most recent Call of the Land (posted August 17, 2016) features Cam Dahl who described issues associated with pre-harvest application of pesticides.

Weekly Update – Crop reports

Crop reports are produced by:

– Manitoba Agriculture, Rural Development (August 8, 2016).

– Saskatchewan Agriculture Crop Report (August 8, 2016) which is also posted in a printer-friendly version.

– Alberta Agriculture and Forestry (for August 2, 2016).

The USDA publishes a Crop Production Report (Posted August 12, 2016) and a Crop Progress Report (posted August 15, 2016) which includes harvest and condition ratings for winter wheat, spring wheat, oat, barley, plus range and pasture conditions. 

The USDA also produces a World Agricultural Production Report (July 2016) which estimates production across the globe for corn, cotton, rapeseed, and wheat but also includes tabular data for other grains.

Weekly Update – Time of Swathing for Canola

The Canola Council of Canada created a guide to help growers estimate swathing time in canola.  A screen shot of the downloadable Canola Swathing Guide has been included below for reference.





Weekly Update – Harvest Sample Program

The Canadian Grain Commission is ready and willing to grade grain samples harvested in 2016.  Samples are accepted up to November but send samples as soon a harvest is complete.

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.  The data collected also helps Canada market its grain to the world!

More information on the Harvest Sample Program is available at the Canadian Grain Commission’s website where growers can register online to receive a kit to submit their grain.  


In exchange for your samples, the CGC assesses and provides the following unofficial results FOR FREE:
  • dockage assessment on canola
  • unofficial grade
  • protein content on barley, beans, chick peas, lentils, oats, peas and wheat
  • oil, protein and chlorophyll content for canola
  • oil and protein content and iodine value for flaxseed
  • oil and protein for mustard seed and soybeans
Many producers find having both grade and quality information on their samples before delivering their grain to be helpful.

Weekly Update – Previous Posts



The following is a list of previous 2016 Posts – click to review:

Alfalfa weevil

Aphids in canola 

Bertha armyworm development and flight
Bertha armyworm



Cabbage root maggot
Cabbage seedpod weevil
Canola scouting chart
Cereal leaf beetle
Crop protection guides
Cutworms


Diamondback moth

Environment Canada’s radar maps to follow precipitation events


Flea beetles in canola

Iceburg reports
Insects in our diet



Lygus in canola

Monarch migration

Multitude of mayflies


Pea leaf weevil monitoring

Predicted cereal leaf beetle development

Predicted lygus bug development
Predicted wheat midge development

Swede midge


Thrips in canola


Weather Synopsis (Week 12)

Wheat midge
Wind trajectories

Insect of the Week – Assassin bug

Assassin
bug
Last
year, the focus of the Beneficial 
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 feature beneficial insect is the Assassin Bug. I love it when a common
name is so apt. Assassins (at least in the movies) are guns for hire and
they’ll take out whoever is on their list. They’re usually the bad guys but on
occasion can be a force for good (e.g.
Jason Bourne). Similarly
in the insect world, assassin bugs are indiscriminate in who they attack,
preying on immature and adult forms of beneficials and pests alike by patiently
lying in wait for their target to come within stabbing distance.
For
more information about these natural enemies, 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).

Assassin bug (Reduvius personatus), Keith Roragen, Flickr

Insect of the week – Syrphid flies

This week’s Insect of the week is an important aphid predator, the syrphid fly. Syrphid flies are more commonly known as hoverflies. There are many species in the Syrphidae family and the adults of several species mimic wasps.   


Wasps are characterized by having two pairs of wings, a tightly tapered ‘waist’, long antennae, and a yellow and black body. In contrast, hoverflies or syrphid flies have one pair of wings, a less distinct ‘waist’, have short antennae, and an abdomen striped yellow and black or a black and brown body. Syrphid flies also have relatively large compound eyes  characteristic to all Diptera spp. Mimicking the appearance of a wasp helps protect syrphid flies from predation.  

Find out more about hoverflies and more at the Insect of the Week page!

Two syrphid flies on a hawkweed flower.
(c) 2015 John Gavloski, Manitoba Agriculture, Food and Rural Development