Apple pith moth

Insect

Apple pith moth

Blastodacna atra (Haworth)

Lepidoptera: Agonoxenidae

Distribution: ME, NH, MA, CT, RI.


Head of adult is covered with white scales; forewings are narrow, mostly black or dark brown with white marks and usually with an irregular faint, rusty yellow line in the middle, and with two prominent black scale tufts. When the wings are folded they appear to have three pairs of white spots (A). Young larva is yellowish with a dark brown head, but turns more reddish in color in the final instar (B).

  • Crops Affected: apples

    Damage

    Attacks apple. Damage is most noticeable in the spring, either just before or after bloom, when the larvae are actively feeding in the woody tissues at the bases of new shoots of apple trees, causing leaf wilt and die-back of blossoms and terminal shoots (C). The larvae usually attack spurs and the stems of apical shoots, which stimulates the growth of laterals.

    Management

    Effective control can be obtained by the application of an insecticide in late summer (about 2 months after petal fall), when adults are active, as well as early spring, when overwintering caterpillars emerge from their shelters.