When the soil warms up again in the spring, the large, mature grubs move back into the upper soil levels, where they transform into adult beetles that emerge in early summer and start the whole process over again. The key to controlling grubs is to kill them before they hatch and begin to . Signs of a Grub Problem Raccoons, skunks, armadillos, or birds dig up your yard searching for large, mature grubs to dine on. The dead patches of grass in your lawn peel back like pieces of loose carpet because the grubs have eaten the roots that usually hold the turf in place.
Adult beetles lay eggs in the soil; the eggs grow into larvae (grubs). Depending on the species the grubs may feed in the soil for a year or more. The most effective timing of insecticides is when the larvae are young and near the surface of the soil. This is typically in summer and fall. Lawn grubs are the wriggly, worm-like larvae of different types of beetles, like Japanese Beetles and June Bugs, that hatch in the spring and summer. These pests are roughly an inch long, curl up into a C-shape when disturbed, burrow into your lawn, and feed on your grassroots.
The grubs we turn over in the spring garden are essentially in hibernation. They remain in a non-feeding state until May, when they undergo pupation before emerging from the ground as an adult in June and July. As alarming as these juicy springtime grubs appear, they do little harm to plants in the spring. Adult grubs lay eggs in the soil during the summer. Once the grubs hatch, they feed on plant roots and descend deep into the soil once it becomes colder, to spend the winter there. In the spring, grub worms return to the surface and keep feeding on the roots until they become ripe. The biggest damage is caused from mid-September to November or.