SCOTT, Sask. – With most of Saskatchewan’s parkland infested with wheat midge this year, farmers have yet another major pest to worry about.
Adult wheat midge started to emerge in early July from infested spring wheat, durum and Canada Prairie Spring wheat crops and will do so for about six weeks. Populations tend to peak in the third week of July.
Agriculture Canada entomologist Bob Elliot said farmers can watch for the tiny bugs flying in their crops on calm, warm nights during twilight.
That’s when the females lay their eggs within the head of the wheat. Larvae then feed on the developing kernels, causing yield loss and downgrading.
Read Also
Agriculture ministers agree to AgriStability changes
federal government proposed several months ago to increase the compensation rate from 80 to 90 per cent and double the maximum payment from $3 million to $6 million
Generally speaking, one adult per four to five heads of wheat means there is potential for economic losses in the crop, said Elliot.
Grading standards strict
Two or more larvae feeding on a kernel will likely result in yield loss. A single larvae will scar the kernel, causing grade loss.
And the grading standards for wheat midge damage are stringent, Elliot warned.
Wheat midge larvae can remain viable in the soil for up to 13 years. “They’re just like a weed seed.”
He outlined several ways to manage the pest:
- Plant resistant crops: Pulses, oilseeds, forages, barley and oats.
- Plan your crop rotations. Don’t grow wheat on wheat.
- Seed early. Research has shown if a crop is seeded under normal conditions by May 10, losses from midge are 15-25 percent less than infested crops that are seeded after this date. Early-seeded crops flower and head out before the pest emerges.
- Plant cultivars that are less susceptible to midge. Elliot said preliminary research shows some varieties within all classes of wheat are less susceptible to the pest. He won’t release names of these cultivars until the second year of data is compiled.
In the meantime, Agriculture Canada wheat breeders in Winnipeg are working on developing midge-resistant varieties.
If an infestation is suspected, Elliot advises a thorough inspection of the field. Because midge are poor fliers, he said it may be that only the perimeter is infested and needs to be sprayed.
