The state announced Monday that it has wrapped up a nearly two-month spraying campaign to prevent gypsy moth infestations in East Pierce County.
The Department of Agriculture applied five insecticide treatments to trees and other vegetation at a 43-acre site at South Hill Mall and four treatments at a 13-acre residential area near Eatonville Highway and Hilligoss Lane. It was the only ground spraying for the destructive pests done in the state this year, said department spokesman Mike Louisell.
Officials say the treatment is harmless to animals and people.
The spraying period of May 8 through June 28 correlated with the emergence of caterpillars to block them from developing into gypsy moths. The treatments were supposed to happen earlier in the spring.
“Cool, damp weather delayed the start of our treatments this year,” Jim Marra, managing entomologist with the state’s pest program, said in a news release. “This is one of the longest gypsy moth spray seasons that staff can remember. We needed the caterpillars to hatch out and be a certain size before the spray can be effective.”
Traps will be set at both the South Hill and Eatonville sites this summer to check whether any caterpillars survived. The areas will be declared eradicated if no gypsy moths are detected for two straight years.
A smaller site at South Hill Mall was treated in spring 2011.
Statewide, trappers are placing 18,000 small cardboard traps to make sure the non-native moth isn’t becoming a concern in other locations.
The spray treatments in Pierce County were needed because agriculture officials found evidence of reproducing populations at both sites.
Gypsy moths have been found in Washington every year since 1977, and they can cause extensive environmental and economic damage if not controlled.