OBLIQUEBANDED LEAFROLLER (OBLR) Choristoneura rosaceana
Tan in color, with alternating light and dark brown (oblique) bands across their forewings. Female moths are larger and more distinctively marked.
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.
Fully-grown larvae are 0 .75 – 1 in or 19 to 25 .4 mm long, yellowish green with brown to black head capsule.
Apples, pears, walnuts, filberts, pistachios, stone fruit, oaks, berries, grapes, hops, azaleas.
- 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.
- 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).