Biology and management of an invasive white grub, Plectris aliena (Coleoptera: Scarabaeidae), in North Carolina

An invasive white grub, Plectris aliena, was first discovered in Columbus County, North Carolina in 2006. Since its discovery, the insect has caused an estimated $3 million loss to the sweetpotato industry in the state. Information on the biology of this pest is limited. Current studies have been undertaken to determine aspects of the beetle’s biology that could prove useful for developing integrated control strategies. Plectris aliena appears to be univoltine in North Carolina, and it overwinters as late instar larvae. Flight-intercept trap collections indicate that male and female adult emergence occurs between mid-May and late June and that mating activity peaks during the last week of May. Individual females may lay up to 40 eggs in the lab. Larvae develop in the soil where they feed on plant roots. The insect’s complete host range is unknown, but overwintering grubs were found in commercial sweetpotato, corn, and peanut fields.