Insect Gallery

Name: Apple twig borer

Latin Name: Amphicerus bicaudatus

Description: Adult is an elongate, cylindrical beetle, about 1/4 to 1/2 inch long and 1/16 to 1/8 inch wide. Color varies among beetles from reddish brown to almost black. Larva is white with brown head and mandibles, curved body, three pairs of thoracic legs, thoracic segments enlarged; mature larva about 1/2 mm long.

Insects Life Cycle: Adults overwinter in living twigs, emerge in early spring and deposit eggs from April to June in the bark of twigs and small branches. Young larvae burrow into the twig and tunnel along the stem. Larvae mature and pupate in fall and early winter. This twig borer has one generation per year.

Insects Symptons: The insect breeds in injured, diseased, dying, and recently dead trees. Twigs and branches of living hosts may wilt, droop, and die back. Examination of twigs reveals single round entrance holes 1/8 inch in diameter immediately above buds. A beetle may be found in the tunnel from late fall through winter and spring and sometimes until early summer.