Ground beetles are some of the most abundant natural enemies for crop insect pests, but their free services in the field often remain overlooked and under-appreciated, says an entomology professor from the University of Manitoba.
“They’re far more abundant than most people realize, but many of our species are really restricted to the ground and are not very visible during the day. A lot of them are quite active at night where we really won’t see them at all,” explains Jordan Bannerman, in this Wheat School episode recorded at the 2023 Crop Diagnostic School in Carman, Man.
Up to 400 different species of ground beetles have been identified on the Canadian Prairies, and most are generalist predators feeding on a wide range of pests, he says.
“They will feed on pretty much any insect that they come across that is an appropriate size. Some of our larger ground beetle species really like to feed on caterpillars. This includes things like cutworms, true armyworm, Bertha armyworm, and clover worms. Our smaller ground beetle species will feed on quite a variety of things — smaller caterpillars, things like grasshopper eggs,” says Bannerman. “We’ve even observed a few species in kind of a Petri dish type experiment will feed on adult flea beetles if they find them.”
Some species will also chew on and destroy weed seeds.
Ground beetles tend to be found in higher numbers in or near undisturbed areas, including shelterbelts and ditches, where they have more protection for overwintering.
Given their value as a beneficial insect, he recommends choosing insecticide products that have limited or reduced impact on ground beetles, including Bt-based options.
Check out the video below for more on abundant, but overlooked ground beetle population with Jordan Bannerman: