HOSTS: Apple, cherry, hawthorn, mountain ash, pear, and willow.

DESCRIPTION: The adult moth is dark grey to reddish brown with a ½ inch wing span. The fully grown larvae is ½ inch long with a yellowish green body and a pale brown head.

LIFE CYCLE: The adult moth overwinters and after mating in the spring lays tiny green eggs on the underside of the leaf near the midrib. The young larvae feed on the lower epidermis under a loose covering of silk. As they mature they move to the upper surface where they tie the edges of the leaf together at the base. The larvae then skeletonize the upper epidermis between the veins. This species develops rapidly later in the season in western Montana and produces 1 - 2 generations per year.

CONTROLS:

Biological:  Several native parasitic insects have provided adequate control, including a species of tachinid fly and species of braconid, ichneumonid, and chalid wasps. Spiders, pathogens, and other predators have also contributed to control.

Botanical:  Bacillus thuringiensis (Bt-K). Treat newly hatched larvae, before leaves curl. This works best when temperatures are warm (>50ºF). See Bacillus thuringiensis.

Chemical: Spinosad - Treat by spraying newly hatched larvae.