Here’s what last year’s dry summer and a mild winter mean for this year’s Japanese beetles invasion in Wisconsin

PJ Liesch, director of the University of Wisconsin-Madison Insect Diagnostic Lab, began seeing reports of Japanese beetle activity the last week of June, which is typical. Numbers will increase during their prime feeding months of July and August when they damage (but usually don’t kill) roses, grape vines, basil, raspberries, crabapples, birches and ornamentals, among others, by skeletonizing the leaves.