Look into the trees around Vancouver open spaces this summer, and you might notice a lot of milk carton-sized orange and green boxes dangling from the branches.
The Washington State Department of Agriculture workers are setting 34,000 traps around the state to catch the much-loathed European and Asian gypsy moths after 42 of the insects were found in Washington last summer.
Vancouver will have a high concentration of the traps because one Asian gypsy moth — the more problematic of the two varieties — was found at the Port of Vancouver last year.
European and Asian gypsy moths are voracious eaters of more than 100 plant varieties. They’ve have wreaked havoc on forests in 19 Northeastern and Midwestern states. They spread quickly and have extensively damaged hundreds of thousands of acres of forests, which, in turn, harms agriculture, wildlife habitat and stream quality. Once a population is established, it’s practically impossible to eradicate them.
This spring, the Port of Vancouver and part of the Fruit Valley neighborhood as well as several other parts of Washington and Oregon were sprayed with a pesticide approved for organic agriculture to kill gypsy moth caterpillars. The traps are being placed this summer to indicate the effectiveness of the spraying treatments and to catch any gypsy moths they may have missed.
“We treat for caterpillars and trap for moths,” Karla Salp, community outreach and environmental education specialist with WSDA.
The traps are specific to each moth variety, but this year officials are placing traps for the Siberian gypsy moth as well. The traps work by luring in male moths with pheromones from the female where they are then trapped on a sticky surface.
Typically, one trap is distributed for every mile, the maximum distance male gypsy moths can detect a female, but WSDA employees are placing 36 traps per square mile in a 3-mile radius from the center of where moths were discovered. Three miles beyond that, 25 traps per square mile will be placed. Parts of Cowlitz and Skamania counties will also host traps. The work is expected to be finished in mid-July.
“This is what’s helping up find out if spraying was a success,” Salp said.
