The wheat midge has arrived in Washington.
Along with it comes a potential of damage to spring wheat crops, says Diana Roberts, Washington State University Extension area educator in Spokane.
WSU scientists are not recommending that farmers apply insecticides unless they know that they have an infestation causing economic losses.
The midge, also known as the "orange wheat blossom midge,' because of its color and that it infests wheat at pollination or flowering time, originated in Europe and has been a Canadian problem and northern U.S. pest in Bonner, Boundary and Kootenai counties in Idaho.
Now, the pest has been captured in low numbers in pheromone traps in Spokane, Lincoln and Garfield counties in Washington, Roberts reports.
"the wheat midge has been reported previously in Washington," says Roberts. "We put out the pheromone traps because we suspected the midge would move in from Idaho, but we don't know the background population levels over the past few years."
Closer examination of wheat fields in the area has not revealed midge populations that will likely cause economic damage this season.
"We do not recommend that growers go out immediately and spray their crops because that kills beneficial insects such as ladybird beetles," says Roberts. "We are in contact with researchers in Canada who have biological controls for this pest. While the midge populations are still at low levels, we will take the opportunity to bring in the biocontrols."
The adult midge is a fragile insect with a body type similar to that of a mosquito, but about half the size. Other than the orange body, it has conspicuous black eyes, three pairs of long legs and one pair of wings.
The female lays eggs on the awns and heads of wheat plants. These eggs hatch into larvae that crawl inside the floret and feed on the very young, developing grain and cause yield loss and shrunken kernels. The larvae are about the same size, shape and color as the anthers of the wheat floret.