Insects in spring-harvested canola

Some farmers harvesting crops this spring have noticed higher numbers of insects in their samples. These are primarily seed-eating carabid beetles and fungus-eating beetles.

Carabid beetles eat various pest insects, as shown here at canoLAB, as well as seeds. Credit: Gregory Sekulic

Some species of carabid beetles are seed eaters and would normally work on the ground, eating all kinds of seeds and providing a benefit by reducing the weed and volunteer canola seed bank. But this spring they have been climbing up into the windrows, which is how they end up in combine hoppers. These beetles are not worrisome as stored grain pests as they will not breed and multiply in the bin.

The foreign grain beetle (Ahasverus advena) is a common fungus beetle found in and around grain storages. Photo credit: Agriculture and Agri-Food Canada

Fungus beetles have also been showing up in grain samples. They could keep eating in the bin if conditions that promote fungal growth are present. But these conditions — moist, warm grain — also greatly increase the storage risk from heating. When stored grain is dry and fungal growth stops, fungus-eating beetles should die.

Scott Meers, provincial entomologist for Alberta Agriculture, would like samples of beetles found in the combine hopper. This would be for proper identification. Please send samples by putting insects in a vial and placing them in the freezer overnight. Then send the vials to Scott Meers, Crop Diversification Centre South, 301 Horticulture Station Road East, Brooks, Alberta T1R 1E6. With the sample, please provide host crop, collection date, location and contact information. Meers will happily return an identification to the sender once it is completed.