Following its aerial eradication efforts this spring, the Washington State Department of Agriculture is setting up gypsy moth traps on Capitol Hill.

The Capitol Hill deployment is just one of many regions across Washington state receiving the bright orange traps. WSDA estimates that 34,000 traps will be set up across the state this season, a 70% increase from the 20,000 typically set.

WSDA spokesman Hector Castro said this is due in part to the fact that some regions of the state, such as Eastern Washington, did not receive any trapping at all in 2015 and thus are being focused on in 2016. Additionally, regions that were treated with the bacteria Btk to eradicate the moths are receiving “intensive trapping.” The area around Miller Park was sprayed with Btk in April, and Castro says the results of the trapping this summer will help the WSDA determine if that treatment was effective.

“On Capitol Hill we are going to have more traps than in previous years to make sure that that eradication was effective,” said Castro. “It will likely be September before we know if we were effective.”

The state has been treating for gypsy moths since 1979. CHS wrote here about the differences between the moths, the history behind the infestation and why they’re such nasty neighbors. Gypsy moths caterpillars are incredibly voracious and not terribly picky, having been documented eating over 300 species of trees and shrubs.

WSDA plans to install 256 traps on Capitol Hill, distributed evenly in a four-square-mile radius around the area treated for moths in April.

Castro also said that trapping some gypsy moths this summer does not mean the spraying in April was a bust. “We can be effective and still end up finding some gypsy moths,” he said. If WSDA does find moths in the traps come September, they will assess the situation and decide whether another Btk spraying is necessary.

The traps are being set up this week and will be checked frequently during the summer. The traps are equipped with pheromone lures to attract the gypsy moths and coated with a sticky substance to capture insects that come to explore the smell. Castro said the lures are not an insecticide and are not harmful to humans.

You can learn more at agr.wa.gov/gypsymoth/.