Latin name: Argyrotaenia franciscana
Reason for Concern:
1) Major crop contaminant in Oregon and SW Washington blackberries.
2) Damage from webbing/feeding on foliage is not economic.
3) Predominant harvest contaminant leafroller species in Skagit, Clark, and Cowlitz counties of Washington, as well as Oregon's Willamette Valley.
Larvae are light brown to yellow green with a brown head. Full grown larvae are, a 2-3 mm to ¾” long. When disturbed, they wiggle backwards and drop to the ground on a silken thread. Rolled leaves webbed together form a protective nest indicating the presence of leafroller larvae. Adult moths are tan or gray with darker mottling on the forewings.
Overwintering in canes and dried leaves, larvae may feed during winter warm periods, but become active in spring. Adult moths emerge in late spring to lay eggs. Hatch of 1st summer brood often coincides with harvest and therefore contaminates fruit. There are 3 or 4 overlapping generations a year.
- Orange Tortrix leafrollers are a major crop contaminant in blackberries in Oregon and Southwest 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.
- On a weekly basis beginning in mid-May and throughout the remainder of the growing season, look for larvae in rolled-up leaves with a webbed cocoon. This should be done by selecting a few random areas of the field and looking for 5 minutes in each area, recording the number of larvae found.
- The Orange Tortrix larva will appear light brown to yellow green, and will appear full grown at ¾” (2-3cm) 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 Orange Tortix larvae will have a much lighter colored head than Obliquebanded.
- Effective Treatment relies on timing applications to when newly hatched, small larvae emerge.