Insect Survey Results – 2021

SARDA Ag Research participates in the provincial insect surveys each year. In 2021, our pest monitoring took us to three municipalities; Big Lakes County (BLC), Northern Sunrise County (NSC), and the MD of Smoky River (SR). Our survey efforts and traps were strategically placed to get the best coverage of the major cropping areas within each municipality.

We monitored 3 Bertha Army Worm Traps, and 3 Diamond Back Moth Traps. We surveyed 3 fields in BLC, 3 fields in NSC and 6 fields in SR for pea leaf weevil, the latest insect pest to make its way to the Peace Region. The pea leaf weevil survey involves looking closely at 50 plants in each field, listing the nodes affected and the number of notches per node. For the wheat midge monitoring, we collected 10 shallow soil samples from 4 fields in BLC, 3 fields in NSC and 4 fields in SR. These soil samples were sent to Shelley Barkley for processing.

SARDA Ag Research would like to thank the producers who gave us access to their land to complete the surveys.

Big Lakes County

The bertha armyworm site in Big Lakes was above the first warning level of 300 moths. Trapping will continue to be important to watch for a possible buildup in the population.

Once again we were seeing pea leaf weevil damage in the survey conducted in early June. No weevils were actually found, however, the level of notching was very low and this does not pose a risk at this time. There were no wheat midge found in the soil samples. Wheat midge could return in 2022 as a threat to wheat production as wet conditions and seeding delays will increase the risk of wheat midge. Overall the risk from wheat midge appears to be low for 2022.

Bertha Armyworm (Baw)

SARDA Ag Research had one trap location near High Prairie in Big Lakes County. Bertha armyworm is very cyclical. In order to catch outbreaks and help producers minimize losses it is necessary to maintain a good monitoring system using pheromone traps. The number of moths caught in the traps informs us of the risk of damaging populations with a 3 to 5 week lead time.

Potential damage may be more or less severe than suggested by the moth count data depending on weather and crop conditions and localized population dynamics. Research has clearly shown that very few fields are ever affected in an area with moth catches less than 300. Even at higher moth counts field scouting is critical for pest management decisions because experience has shown that field to field and even within field variations can be very large.

Pea Leaf Weevil (PLW)

Experience has shown us that high numbers of pea leaf weevil adults in fall will likely mean significant infestation levels in the following spring. The timing and intensity of spring damage is strongly related to the onset of warm conditions (>20oC) for more than a few days in April or May. The earlier the weevils arrive in fields the higher yield loss potential. Extended cool weather delays weevil movement into the field. Yield impact is lower if the crop advances past the 6 node stage before the weevils arrive. The numbers represented here are generated from assessing feeding damage on 10 plants in 5 locations in a field. SARDA Ag Research surveyed 3 fields in Big Lakes County.

photo by Shelley Barkley. Alberta Seed Guide 2017

Wheat midge (soil) (WM)

Wheat midge is an insect that increases in numbers in wet years. Numbers can vary drastically from field to field and we try to sample wheat adjacent to the previous years’ wheat in order to pick up populations if they are present. There is no definitive way to know exactly the risk in any given field so field scouting when the wheat comes into head is critical. The numbers shown here give a general trend of midge populations. Individual fields will have a different risk. These numbers are generated by taking soil samples from wheat fields after harvest using a standardized soil probe.

In Big Lakes County, SARDA Ag Research collected soil samples from 4 fields, representative of the different agricultural areas in the municipality. Zero midge were found.

Northern Sunrise County

Wheat midge (soil) (WM)

photo by Sask Wheat Development Commission

We found no wheat midge in the 3 fields surveyed this year. It appears that the wheat midge risk is very low for 2022. Producers and agronomists should be aware that wheat midge does exist in your area but at this point the risk is very low, but should there be moisture in June and delayed seeding, midge could be an issue.

Pea Leaf Weevil (PLW)

The pea leaf weevil survey once again found some very limited feeding damage (1 feeding notch in 50 plants in one field) in the fields checked in Northern Sunrise. Pea leaf weevil is now established in the Peace region but to this point damage levels have been low and do not warrant any control actions. SARDA Ag Research surveyed 3 fields in Northern Sunrise County.

MD of Smoky River

Bertha Armyworm (Baw)

The bertha trap was well under the first warning level of 300 moths. It looks like the outbreak is over, but it will be important to keep monitoring for the insect. This system gives us warning of what is happening in the fields during the growing season, and a potential outbreak brewing for the following growing season.

Pea Leaf Weevil (PLW)

Damage caused by pea leaf weevil was found in the survey conducted in late May – early June. It is clear that pea leaf weevil is now established in the Peace Region. The notching is very nominal and is not an issue in the Peace at this time.

Wheat midge (soil) (WM)

No wheat midge. In 2022, producers should be prepared to be scouting their wheat as the heads emerge, especially if wet conditions and/or late seeding occurs because pockets of damage could occur.

Diamond Back Moth (DBM)

photo by Canola Council of Canada

Diamondback moth catches were zero! It is generally accepted that diamondback moth adults don’t overwinter in the prairies and that most infestations occur when adult moths arrive on wind currents in the spring from the southern or western United States or northern Mexico. In mild winters there is suspicion that diamondback moth do overwinter in Alberta. To assess the population, a network of 43 monitoring sites has been established across the province. This network is meant to act as part of an early warning system for diamondback moth and should be used in conjunction with crop scouting.