Throughout the course of a growing season, grass can be affected by several damaging insects. One of these is the bluegrass billbug. It gets its name from the long snout or “bill” that it uses to chew on leaves and stems. However, it is the larvae of these insects that cause considerable damage. Adult billbugs are usually seen in spring, and then again in early fall. Damage from their larvae usually appears in July. This damage begins as discolored, irregularly shaped patches. These patches turn yellow/brown, and when the damage is most severe, the turf can be lifted out of the soil with ease. To better understand the when’s and why’s of billbugs and their damage, it’s good to understand their life cycle.
Identification & Life Cycle
Adult billbugs are about ¼” long, with a brown/black body. The distinguishing characteristic is the long, curved snout and bent antennae. The larvae of the bluegrass billbug looks very much like the dreaded white grub, only they are considerably smaller. They have a white, fleshy body with a small orange/red head.
Adults emerge from “hibernation” in the spring and chew small holes in the leaves and stems of turf plants. This damage is not harmful to the plant. They will then lay their eggs in these holes. Those eggs hatch in June/July, and these larvae are voracious eaters. They will chew their way through the plant down towards the “crown”, which is an area near ground level where growth originates.
Here are a few pictures of the damage caused by billbugs, up-close and from a distance:
Control of Bluegrass Billbugs
The saying “an ounce of prevention is worth a pound of cure” certainly applies when dealing with these creatures! The best way to treat them is with a preventative insecticide aimed at eliminating billbugs in their larval stage. The product that UltraLawn uses for its grub preventer is also effective on the larvae of bluegrass billbugs. Should you or residents in the Cedar Rapids or Iowa City area have any questions or concerns, feel free to give the experts at UltraLawn a call and we’ll be happy to assist you!