Masked chafer and green June beetle flights have been up in central Kentucky this summer, according to Dr. Dan Potter, UK Landscape Entomology Researcher. Masked chafers and green June beetles have been very active. Their larvae are responsible for the damage to grass roots caused by white grubs in late summer.
Masked chafers are light brown beetles that are attracted to lights at night or that fly a few inches above the turf after dark.
Green June beetles cruise over turf during the day. Their white grub larvae (Figure 1) feed on organic matter in the soil, not on grass roots. However, their grubs’ nightly visits to the soil surface leave mounds of crumbled dirt around relatively large holes.
Figure 1. Green June beetle white grub. (Photo: Lee Townsend, UK)
Management
Sport field managers seeing lots of green June beetles hovering (especially on bermudagrass), might want to use a preventive application of Merit (or generic), Arena, Meridian, or Acelepryn. According to Dr. Potter, this may prevent later damage from the mounding, as well as the huge mess from grubs dying on the surface after a curative application. Usually green June beetle activity is localized so treatment can be limited to high-priority areas where lots of beetles are seen.
By Lee Townsend, Extension Entomologist
Kentucky Pest News 