Grubs that feed on turf in May or September are associated with which beetle?

• A. June beetle
• B. Black turfgrass ataenius
• C. Japanese beetle
• D. Rust fungus

Answer: (C)

Grubs that feed on turf roots in spring and again in the fall point to a beetle whose larvae are active during those two periods—that matches the Japanese beetle. Their grubs hatch in spring and resume feeding as soils warm, then again before winter as temperatures drop, causing root damage in May and September. Other pests like June beetle grubs are more typically prominent in a different window (late spring into early summer), black turfgrass ataenius has its own distinct crown-tissue feeding pattern, and rust fungus is not a grub at all. So the timing of root-feeding in May or September is characteristic of Japanese beetle.