Description:

Adults:
Tan in color, with alternating light and dark brown (oblique) bands across their forewings. Female moths are larger and more distinctively marked.

Eggs:
Dull, greenish yellow eggs are laid in flattened, overlapping masses of up to 200 on leaves. Egg mass is approximately 0.275 by 0.551 in or 7 mm by 14 mm in diameter.

Larvae:
Fully-grown larvae are 0 .75 – 1 in or 19 to 25 .4 mm long, yellowish green with brown to black head capsule.

Host:
Apples, pears, walnuts, filberts, pistachios, stone fruit, oaks, berries, grapes, hops, azaleas.

Damage:

• Larvae from overwintering generation become active in March and April, feeding on leaves and developing fruit.
• Severely damaged fruit or clusters are often aborted by trees. Those remaining are deeply scarred and deformed.
• Summer generation larvae cause the most serious damage by shallow feeding in the skin (0.06 inch or 0.16 mm deep) or small holes near the stem end of the fruit.
• In hazelnuts, the second generation can cause nut drop by feeding on the shell of the developing nut.

Phenology:

• Two to three generations per year (in hazelnuts only two generations).
• Overwinters as third instar larvae in hibernacula in bark crevices.
• Adult emerges in mid-May in warmer regions, mid-June in cooler districts.
• Earliest emergence is May 15 (Hood River, OR), June 1 (Yakima, WA).