Japanese beetles could spread throughout Washington state, US, in 20 years
Published:15 Aug.2023 Source:Washington State University
Without intervention, the colorful but devastating Japanese beetle could make its way across the evergreen state within two decades, according to a study of their potential dispersion. The iridescent, green-and-copper beetles damage plants by 'skeletonizing' their leaves, chewing up all the soft green parts between the veins. They eat over 300 plants and pose a serious threat to Washington agriculture as some of their favorite crops include grapes, hops and cherries.
The study found that Japanese beetles would most likely thrive in the dry, agriculture-rich southeastern part of the state, where the first individuals were found three years ago. If they were to escape the quarantines in place in those areas, modeling shows they would likely spread throughout the region from Yakima to the Tri-Cities and north past Moses Lake.
While the Cascades are a barrier, there are large areas of Western Washington that also have highly suitable habitat for Japanese beetles.