Masked chafer adults (Figure 1) are among the many night-flying insects attracted to lights. Large numbers can accumulate around windows and outdoor lights, or be seen hovering over the turf after dark. While similar to May beetles, Japanese beetles, and other members of the scarab family, these insects do not feed as adults. However, large numbers of them may point to potential white grub problems in turf.
Female masked chafers enter turf to lay eggs. Their white grub larval stage, along with that of the Japanese beetle, can be a significant pest because of their feeding damage to roots of cool season grasses. Drought stress due to root damage inflicted by white grubs will not become apparent until late summer or early fall.
Many of the current products target small grubs, so treatment must be applied about now. It can be difficult to anticipate the need for a preventive treatment but buzzing night flights of these beetles can identify sites that should be protected. A list of insecticides for control of white grubs in turf can be found in Insecticides for Control of White Grubs in Kentucky Turfgrass (ENT-441).
By Lee Townsend, Extension Entomologist