TechNotes Tips - 07.05.02

Japanese adult beetles are emerging and feeding on susceptible plant material. Extremely sensitive plant material includes American mountain ash, evening primrose, Japanese maple, hollyhock, crabapple, and American linden. The feeding of Japanese beetles generally does not overly stress the plants (unless severe defoliation occurs). However, defoliation caused by this insect reduces the aesthetic appearance of the plant material and the landscape. Skeletonizing of the leaves is the most common symptom. Regarding homelawns adult Japanese beetles do not cause damage. The damaging stage occurs when the adults lay eggs which hatch into grubs that feed on the turfgrass roots. In turf situations controlling the adult from laying eggs is an ineffective control method.

Conditions remain favorable for brown patch on tall fescue and perennial ryegrass turfs. Cultural practices to minimize disease severity include minimizing overwatering of the turf, and reducing nitrogen applications. Wet conditions along with succulent growth enhances the severity of brown patch.