A Washakie County invasion

WORLAND – A new species of bug has arrived in Washakie County, and has multiplied to the point that state entomologists and pest control specialists have taken notice. Originating in Asia, where they feed on the elm family of trees, the elm seed bug was first noticed in Idaho in 2012.

“Jarrod Glanz [with Washakie County Weed and Pest] notified me of a sudden, significant elm seed bug population around March, and we identified it fairly quickly,” said University of Wyoming Assistant Extension Entomologist Scott Schell. “They probably hitchhiked from Idaho on an agriculture truck, and based on the numbers [now in the thousands] they have probably been in the Worland area long enough to reproduce.”

While the insect poses no threat to people or plants (the primarily feed on the seed of the elm), they do congregate in large numbers and can become a nuisance when they are attracted to yards and homes, and seek shelter inside when available.

“Making sure your windows and doors are sealed will help,” noted Schell, who also recommends using a Pyrethrin- based insecticide to keep them off buildings and landscapes.

One disadvantage to the insect is a distinct smell when killed or smashed, described by the U.S. Department of Agriculture as “an odor that some people find unpleasant, but which we characterize as an over-ripe cantaloupe mixed with turpentine.”

For identification purposes, the insects are 1/3-inch long at adulthood, with a dark brown body with red highlights. Their most identifying feature is a dark, backward-pointing triangle on the back, and narrow white bands on the abdomen.

“They over-winter as adults, so it’s important to watch for them finding shelter in sheds, basements, and under home siding in the late fall,” said Schell.

Caitlin Youngquist with the UW Extension Office in Worland noted, “We do have information available at the Extension Office on management of the elm seed bug. And as always, they can bring samples in to the office for identification.”