Cranberry-Cranberry fruitworm

Acrobasus vaccinii

Pest description and crop damage This pest overwinters as larvae encased in a hibernaculum. Moth emergence occurs during late June and can be monitored with pheromone traps. Eggs are laid singly on the fruit and oviposition may be withheld until berries are of appropriate size and color (e.g., "BB to pea sized"). Larvae enter the fruit immediately upon hatch and may consume five to six fruit during development. Best control is achieved with applications of long residual insecticides.

Management-chemical control: COMMERCIAL USE

  • chlorantraniliprole (Altacor) at 0.066 to 0.099 lb ai/a. PHI 1 day. Apply when fruit are "BB to pea size" and repeat application 10 to 20 days later. Do not exceed two consecutive applications of chlorantraniliprole (Group 28 insecticides) or three applications per crop season.
  • methoxyfenozide (Intrepid) at 0.16 to 0.25 lb ai/a. PHI 14 days. Apply when fruit are "BB to pea size"; repeat application 10 to 14 days later. Do not exceed 1.0 lb ai/a per season.
  • spinetoram (Delegate) at 0.05 to 0.09 lb ai/a. PHI 21 days. Toxic to bees, but thoroughly dried residues are safe. If using during bloom, apply at night and it must be completely dry by morning. Medium-residual.