Latin name: Choristoneura rosaceana
Reason for Concern:
1) Dominant leafroller species in caneberries in British Columbia and northern Washington. Egg hatch timing makes it less of a problem in southern growing regions.
2) In the south larvae usually appear after harvest of primary varieties and only a potential problem in late ripening blackberries.
3) Foliar webbing and feeding damage is rarely economic. Larvae are a potential harvest contaminant.
Larvae are yellowish green caterpillars, up to 1”, with a dark brown or black head and shoulders. When disturbed, they wiggle backwards and drop to the ground on a silken thread. Larvae form protective nests in webbed rolled leaves during pre-bloom and harvest time. Some larvae feed within berries and may not be noticed until harvest. Adult moths, predominant during pre-harvest, have dark brown bands running at oblique angles across the wings.
Obliquebanded leafrollers overwinter as young larvae, often between canes. They feed on new leaves, buds and rolling leaves, from April to June, then pupate and emerge as moths. Moths mate and lay eggs on leaves and canes. Hatched leafrollers feed on foliage and ripe fruit and can contaminate harvested berries.
- Though it has a major potential for crop contamination in Northen Washington and British Columbia, only late variety blackberries have a high susceptibility to this pest in the Willamette Valley and SW Washington.
- In mid-April, begin pheromone trapping by placing 1 trap for every 5 acres, and changing the lure every 28 days.
- As the pheromone attractant for Orange Tortrix and Obliquebanded Tortrix is very similar, it is necessary to distinguish between the two while trapping. Orange Tortrix is considerably smaller than the Obliquebanded, and the Obliquebanded generally has much thicker, more pronounced, diagonal lines across its wings. Carnation Tortrix will also sometimes be caught and is easily discernible by its bright orange coloring on the underside of its wings.
- About a week after peak flight, begin looking for larvae in rolled-up leaves with a webbed cocoon on a weekly basis.
- The Obliquebanded larvae are yellowish green caterpillars, and will appear full grown at 1” long. When agitated, it will wiggle vigorously backwards and drop to the ground on a silken thread. Orange Tortrix larvae differ from Obliquebanded larvae in that the Obliquebanded will have a brown or black head.
- During harvest, inspect fruit for larva contamination.