How to Get Rid of Japanese Beetles on Roses
Hand-pick Japanese beetles into soapy water in the early morning when they are sluggish, and remove them daily during the few weeks they are active. Avoid pheromone traps near roses, which draw more beetles in.
Japanese beetles skeletonize rose leaves and chew blooms during a few intense weeks in early to midsummer. The most effective home control is also the simplest: in the cool of early morning, when the beetles are slow, knock them into a jar of soapy water. Doing this daily through their season keeps numbers down and, because feeding beetles attract more, reduces the crowd.
Avoid the common mistake of hanging pheromone traps near your roses — they lure far more beetles into the garden than they catch. For heavy infestations, targeted treatments exist, but persistent hand-picking and healthy, vigorous plants usually see roses through the season.