Alberta Farmers may be finding large amounts of ground beetles this spring when combining their overwintered canola fields.
These beetles are six to nine mm in length and are black.
Researchers have concluded that unusually cool summer temperatures and a late harvest are the likely causes of an abundance of canola seed on the soil. This abundant food supply allows a larger that normal amount of adult ground beetles to survive the winter and emerge in spring.
Research scientist with Agriculture and Agri-Food Canada in Lethbridge, Kevin Floate, says this outbreak looks like one that happened 10 years ago. Outbreaks of ground beetles were reported in areas across Alberta in 2010 after an unusually cool summer and late harvest that was delayed by snow in 2009.
Some of the areas that saw ground beetle outbreaks in 2010 were sites near Camrose, Falher, High Prairie, Vegreville and Wetaskiwin.
“Given the large numbers of unharvested acres of canola last fall,” Floate says, “I thought conditions might be ripe for such outbreaks this spring.”
Researchers including Floate are looking to connect with farmers who are finding a large number of ground beetles while combining their overwintered fields.
In addition to the contact information of farmers finding these beetles, Floate is looking for:
• A few dozen beetles per location to determine species composition;
• Cropping history of the field going back at least two years;
• Scope of the affected acres of outbreak;
• And quantification of beetle numbers, such as high-resolution photos or an estimate of the number of beetles in a square metre.
Ground beetle eggs laid in the soil over the next few weeks will produce more adults later this summer and could lead to more reports of outbreaks.
Floate notes that farmers should not spray the beetles, as they are beneficial rather than pest insects. Adult ground beetles feed on the seeds of weeds and other plants lying on the ground. Their larvae eat other insects including pest species such as caterpillars.