Walnut Husk Fly
Apricot, nectarine, peach
The walnut husk fly is a tephritid fruit fly like the apple maggot and western cherry fruit fly. The adults are about the size of a house fly and have patterned wings with an inverted “V” at the tip. It lays eggs in the husk of walnut after the husk has softened a bit. It will also lay its eggs in softening peach and nectarine fruits, especially where husk fly numbers are elevated due to the presence of non-treated walnut trees. Larvae (maggots) feed within fruits.
Small maggots inside peach/nectarine or apricot fruit; small brown tunnels in fruit.
Yellow sticky traps baited with ammonium carbonate.
Treatment Threshold: No threshold determined.
Degree Day Model
Treat by 7-10 days after the first adult flies are caught or beginning in late July.