The Problem

Midge Damage

Wheat midge infestations can reduce crop yield and lower the market grade of harvested grain. For example, in 2006, Prairie growers lost approximately $40 million due to midge damage, which caused both downgrading and yield reduction. For an average wheat grower, these losses can range from $20 to $75 per acre.

Crop damage occurs when the midge larvae feed on the developing wheat kernel. Grain damage ranges from a slight change in shape, to a kernel that is completely shrunken and deformed, to complete abortion of the kernel. The damaged kernels can cause downgrading in wheat samples and 40-50% are blown out of the combine during harvest.

View midge damage photos on the Canadian Grain Commission website.

Midge Distribution

Wheat midge is distributed throughout all wheat growing areas, where it lies in wait for optimal conditions to allow local populations to flourish. 

Midge Emergence

Midge emergence can be modeled using accumulated temperature calculations called Growing Degree Days (GDD). The Canadian Wheat Board provides midge emergence maps for the Prairies, updated daily from mid-June until the end of July.