Weekly Update – Wheat midge

David Giffen, Ross Weiss, Owen Olfert and prairiepest_admin
Week 9

Wheat Midge (Sitodiplosis mosellana– Reminder – The previous Insect of the Week (Week 7) features wheat midge!  

Simulation modelling is used to predict wheat midge emergence across the Canadian prairies.  The model has not changed significantly from last week. The map below predicts the geographic distribution and corresponding accumulation of heat units necessary for wheat midge to emerge from puparia developing in the soil.  


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. 

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.  

NEW – Alberta Agriculture and Forestry has also released a YouTube video describing in-field monitoring for wheat midge this week.  

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.

Weekly Update – White grubs in field crops

Kevin Floate and prairiepest_admin
Week 9

Scarabaeidae – Reminder – Each June brings scattered reports across the Prairies of white grubs associated with crop damage.  In fact, several species of Aphodius, Phyllophaga, Polyphylla or even small Aetenius produce larvae described as “white grubs”.  

Recently, crop damage reports have been associated with a grub identified as the larvae of the beetle Aphodius distinctus (see below). This common beetle is not known to be a pest, but there is an ongoing effort to gather information to develop a ‘pest’ profile.  Additional information is online at Top Crop Manager. Please send reports of this insect and associated information to Dr. Kevin Floate (Agriculture and Agri-Food Canada, Lethbridge, AB).


Weekly Update – Painted Lady Butterfly

Jennifer Otani
Week 9

Painted Lady Butterflies (Lepidoptera: Vanessa cardui) – Back on Week 6, we posted information and links related to the adult.  

UPDATE – This week, Alberta Agriculture & Forestry reminded their network of cooperators to watch for V. cardui larvae because the species has a broad host range and can feed on soybean (Action threshold=>25% defoliation), sunflowers, borage and dry beans in addition to several species of thistles (including Canada thistle) and mallow. 

In addition to the Week 6 information linking to the Butterflies of Canada entry for Vanessa cardui, the Butterflies and Moths of North America website tracks confirmed sightings of V. cardui (screenshot provided below).

The Butterflies and Moths of North America website also includes some verified photos of larvae to compare to when scouting.  Here’s screenshot below of the photo provided by T. Stout to hasten the need to link to this valuable resource!


Weekly Update – Monarch migration

Jennifer Otani
Week 9

We again track the migration of the Monarch butterflies as they move north by checking the 2017 Monarch Migration Map!  A screen shot of the map has been placed below as an example (retrieved 22Jun2017) but follow the hyperlink to check the interactive map!  They’ve migrated into southern Manitoba (various), southeast Saskatchewan (near Rhein), and now Alberta (near Sylvan Lake)! 


Weekly Update – Previous Posts

Jennifer Otani
Week 9

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

Alfalfa weevil (Week 7)

Brood X Cicadas

Cabbage seedpod weevil (Week 8)

Canola scouting chart
Cereal leaf beetle
Crickets with your popcorn
Crop protection guides
Crop reports (Week 8)

Diamondback moth

Flax scouting chart

Flea beetles

Grasshopper development (Week 8)

Iceberg reports

Lily leaf beetle

Pea leaf weevil
PMRA Pesticide Label Mobile App
Provincial Insect Pest Reports (Week 8)

Nysius niger (Week 8)

Ticks and Lyme disease

Weather radar

Wind trajectories


Insect of the Week – Cereal aphids

Jennifer Otani
Week 9
This week’s Insect of the Week is the group of aphids known
as cereal aphids. These aphids include the corn leaf aphid, the English grain
aphid, the oat-birdcherry aphid and the Russian wheat aphid. They feed on
cereal crops and are vectors of viruses, causing lower crop quality and yield. There are several natural enemies of cereal aphids, including various species of wasps and beetles. 

For more information on cereal aphids, see our Insect of the Week page. 

English grain aphid – adult, nymph (Tyler Wist, AAFC)

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


Weekly Update – Greetings!

Jennifer Otani, David Giffen, Erl Svendsen and Owen Olfert
Week 9


This week AAFC Staff are out surveying so the Weekly Update will be released in segments.  Please access the series of Posts for Week 9 (Jun 29, 2017) to reach the most up-to-date information.   

Remember, if we’re in the field, you should be too!

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 easy steps!

Weather Synopsis

Ross Weiss, David Giffen, Owen Olfert and prairiepest_admin
Week 9

Weather synopsis – Our AAFC Staff are busy surveying this week so be sure to check back for updates!

Precipitation for the growing season is presented below (April 1-June 27, 2017) followed by the precipitation expressed as Percent of Normal for the same period.

Over the past seven days, the greatest precipitation fell in northern growing areas along areas typically grouped as Boreal Plains (June 21-27, 2017).  Southern Alberta, southeast Saskatchewan and southwest Manitoba received the lowest amounts of precipitation over the same period.

The lowest temperatures across the prairies over the past seven days (June 21-27, 2017) are mapped below.  Although there was little chance of frost, much of the prairies recorded lows ranging from 0-4°C.

In contrast, the highest temperatures recorded over the past seven days (June 21-27, 2017) are presented below.  The field crops in some of these areas endured daily fluctuations of 20-25°C.

The updated growing degree day map (GDD) (Base 5ºC, March 1 – June 25, 2017) is below:

While the growing degree day map (GDD) (Base 10ºC, March 1 – June 25, 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 – Predicted Bertha Armyworm Development

David Giffen and prairiepest_admin
Week 9

Bertha armyworm (Lepidoptera: Mamestra configurata– Bertha armyworm should be in the adult stage across the prairies this week.  The map illustrates predicted appearance of adults (percent of the population) across the southern prairies.

For those monitoring BAW pheromone traps, compare trap “catches” to the following reference photo kindly shared by Saskatchewan Agriculture:

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.