Navel Orangeworm

Amyelois transitella

Adult navel orangeworm
Adult navel orangeworm. Photo courtesy of Simon Hinkley & Ken Walker, Museum Victoria. Licensed under CC BY 3.0 Australia.
Navel orangeworm larvae are a major pest of almonds, pistachios, walnuts, and other tree fruits and nuts. They are native to the southwestern United States and Mexico.
Adult moths are silver-grey in appearance with bands across the wings. They have two protrusions from the head which look like a snout.
Adult navel orangeworm head showing characteristic protrusions
Adult navel orangeworm head showing the two protrusions. Photo courtesy of Simon Hinkley & Ken Walker, Museum Victoria. Licensed under CC BY 3.0 Australia.
Larva are orange or cream in color. They have two cresent-shaped markings behind the head.
Navel orangeworm larva showing characteristic markings behind the head
Navel orangeworm larva showing the two markings behind the head. Photo courtesy of Simon Hinkley & Ken Walker, Museum Victoria. Licensed under CC BY 3.0 Australia.
Navel orangeworm larvae burrow directly into fruit and nuts causing direct yield loss but also providing an entry for secondary fungal infections. The third generation is typically most damaging in almonds and pistachios since it corresponds with the time period in which nuts are vulnerable.
Cultural control methods for include removing mummy nuts in the winter (which are overwintering sites for larvae) and harvesting before the the third generation, which is the most damaging.
Insecticides can be used to control the third generation. Timing is critical since larvae which have burrowed into nuts are protected from sprays. Always read and follow all label instructions.