Which insect is listed as overwintering in the adult stage and affecting lawns?

• A. Japanese beetle
• B. June beetle
• C. Bluegrass billbug
• D. European chafer

Answer: (C)

The main idea is when the insect survives winter and how that affects when you see damage on lawns. The bluegrass billbug overwinters as an adult, meaning some mature bugs survive the cold and remain active enough to resume feeding as soon as temperatures rise. This adult-stage overwintering lets them begin damaging the turf early in the season, often by feeding on the blades and laying eggs near the crowns, which leads to patchy, thinning turf quickly after winter.

In contrast, the other insects in the list typically spend winter in larval or pupal stages, or otherwise do not overwinter as adults. That’s why they don’t fit the description of overwintering in the adult stage affecting lawns. So the insect that best matches “overwintering in the adult stage and affecting lawns” is the bluegrass billbug.