Turfgrass - Masked Chafer Grubs

grub image adult beetle grubs in soil


Annual white grubs, Cyclocephala spp., complete their life cycle in one year. Adults are tan, about 5/8 inch long, and have a dark, mask-like marking over the eyes. Adults are normally present from late June through July. They are highly attracted to lights, and are frequently observed around windows or porch lights. Adult masked chafers do not injure turf or other vegetation.

Masked chafer beetles deposit eggs in the top 2 inches of soil, often in small clusters. Small grubs hatch during late July and early August and immediately begin feeding on grass roots. Most damage occurs in late summer and early fall after the grubs have reached the second and third larval stages. With the onset of cold weather, grubs move deeper in the soil to overwinter. As soil temperatures warm in the spring, they return to the root zone, feed for a brief period, pupate, and emerge as adults to begin a new cycle. Spring feeding is not as destructive to turf as late summer and fall feeding. Consequently, spring treatments are rarely required.


Breaking Entomological News...

  • Insect Science major Earl Agpawa (conducting undergraduate research with Joe Louis and Eileen Hebets) was named the 2020 winner of the ESA’s Plant-Insect Ecosystems Undergraduate Student Achievement Award.This is a national award that recognizes outstanding accomplishments in entomology by an undergraduate student working with insect-plant interactions. Congratulations, Earl!
  • PhD student Sajjan Grover (mentored by Joe Louis) was named the 2020 winner of the ESA’s Plant-Insect Ecosystems Kenneth and Barbara Starks Plant Resistance to Insects Graduate Student Award. This is a national award recognizing a graduate student for outstanding work in the area of host plant resistance. Congratulations, Sajjan!
  • Dr. Joe Louis receives a grant to study resistance in sorghum to fall armyworm
  • Check out the Emerald Ash Borer Resource Center, and our Emerald Ash Borer Look-Alike Insects Sheet - Be Sure Before You Treat!