Male beetles fly during mid- to late morning. Female beetles produce substances that attract the males to them. The female beetle constructs a walnut-sized ball of soil in which she lays 10 to 30 eggs. Each female may lay as many as 75 eggs during a 2-week period. Eggs hatch in about 2 weeks.
Young grubs begin feeding on organic matter.
Green June beetle grubs are the only grub species in the southeastern U.S. that come out of the ground at night and move on their backs from one place to another. Green June beetle grubs also come to the surface following an insecticide application or when the grounds are flooded with water. The grubs emerge from the ground the next evening and die on the turf or soil surface. In turf, the grubs usually leave small mounds of soil around the mouth of each tunnel. By August, grubs are large enough for mounds to be seen on short mowed turf and by mid-September on taller grass.