Light traps have been catching increasing numbers of masked chafer beetles in the last two weeks. Adults have also been spotted walking the turf at night. Chafers can be pests of both warm and cool season turfgrasses so it is important to monitor and keep track of previous infestations. When adults are actively flying, mating and egg lay are at their highest. The best time to treat for a large chafer white grub population is about 3-4 weeks following peak flight activity.
Like sugarcane beetles, masked chafers are attracted to light sources at night, which could be a useful place to monitor for insect populations.
Pheromone traps have also been catching large numbers of Japanese beetles in the last week. Although beetle damage may not be apparent, adults are still flying, mating and laying eggs. Similar to masked chafers, the best time to treat an area for white grubs is 3-4 weeks after peak flight.
Something to keep in mind, white grubs are more likely to be feeding near the soil surface when the soil is moist. The best time to apply an insecticide will be after significant rainfall.
For more information on all scarab beetle adults, visit http://www.turffiles.ncsu.edu/Insects/White_Grubs.aspx