Polydrusus spp.

There are over 180 known species of Polydrusus weevil, four of which are native to the United States. Two non-native, introduced species of weevil in the genus Polydrusus are potential pests of ornamentals, urban street trees, and occasionally fruit crops. Both Polydrusus formosus and P. impressifrons were introduced into North America from Europe in the early 1900's. Both are found in the northeastern United States. Adult weevils of these two species feed on the leaves and buds of some hardwood and fruit trees. Adult weevils of P. formosus are slightly bigger (0.2-0.27 inches) than P. impressifrons (0.15-0.22 inches). Both have a brilliant green, iridescent color, with subtle differences to the black markings on the elytra (hardened wing covers). In both species, a single generation per year is known in New England. Adults emerge from the soil by late May/early June and feed on host plant buds or leaves through August. In southern New England, adult activity may be particularly noticeable from June to July during the daytime. Adult female weevils lay groups of tiny, white, cylindrical eggs on the surface of the soil beneath host plants or in the cracks and crevices of the bark. Females may lay anywhere from 800-2,000 eggs in their lifetime. Eggs hatch, and the larvae (immature weevils) feed on the roots of their host plants. They overwinter in this life stage and pupate the following spring before emerging again as adult weevils.