White Grubs are the most common pest problem in the Chicagoland area. There is always a certain amount of all pest insects that your lawn can tolerate, so you need only employ pest control when it seems apparent to be the cause of the damage to your turf. For all species of White Grub it becomes an infestation when you can pick out 12 or more Grubs within a square foot.

WHY DO I NEED TO WATCH OUT FOR THE GRUBBENING?

Like all pest related issues with turf management it can be difficult to ascertain whether or not pests are the cause of the damage to your turf, if they are, and especially with White Grubs, you can expect patches of dead, yellowing/browning turf as the Grubs consume the roots underneath your turf. It’s not surprising why you might not want this, and as with all pest problems it can spiral out of control if not caught soon enough.

WHAT ARE WHITE GRUBS?

Public Enemy #! – White Grubs

The White Grub is actually the larval stage of a few species of beetles that live in the Chicagoland area. The Japanese Beetle, and the Masked Chafer Beetle, now the adult stages of these beetles are not a concern with your turf as far as damage goes as they do not eat much when they are fully grown, their primary purpose is to mate and begin the cycle anew so we will discuss their breeding habits and the timeframe for that below. The Grubs themselves are the primary concern as they are the heavy eaters who live under your turf. We have a picture of them for your convenience, the beetles and the grubs themselves. White Grubs are distinct from most of the other pests on this list for their curled up “C” shape they assume when located, and their six legs close to their orange heads.

THE REPRODUCTIVE CYCLE

Japanese Beetle

The Japanese beetle has a one-year life cycle but spends most of its life in the soil as a grub. In spring, the overwintering, partially grown grubs move upward in the soil. From mid-May to June, the young larvae pupate. After pupating, adults begin to emerge from late-June to August. The female Japanese beetles release a pheromone that attracts males, causing them to congregate in groups. Mating and egg laying begins soon after emergence. Japanese beetle adults feed during the day on a wide variety of low-growing plants and later fly to tree leaves. Adults typically live for 30 to 45 days. Once mated, females lay eggs in the lawn and other grassy areas just under the soil surface. Eggs soon hatch and young larvae begin to feed on roots of nearby grass and other plants until cold weather forces them to move deeper into the soil for the winter. As the soil temperatures warm in the spring, the grubs return to the surface to complete their life cycle.

Masked-Chafer Beetle

Annual white grubs have a one-year life cycle. Adult chafer beetles are attracted to vigorously growing turf with damp soil, where they lay their eggs in July. The grubs hatch and feed on decaying organic matter and sod roots until October. When temperatures begin to drop, they tunnel downward in the soil to overwinter. In spring, the grubs move up in the soil and resume feeding. They pupate in May and emerge a few weeks later as adult chafer beetles.