Choristoneura rosaceana
Pest description and crop damage Small caterpillars are tan. Mature caterpillars are green with black heads. In some seasons, caterpillars web in hop cones and cause some damage. They are not usually a serious pest.
Management-chemical control
- azadirachtin (various formulations)-See label for rates. PHI 0 days. REI 4 hr. Works best on early larval stages. Applications can be repeated every 7 days or as needed. Some formulations are OMRI-listed for organic use.
- Bacillus thuringiensis (various formulations)-See label for rates. PHI 0 days. REI 4 hr. Works best on early larval stages. Repeat treatment as needed. Some formulations are OMRI-listed for organic use. Group 11A insecticide.
- bifenthrin (various formulations) at 0.06 to 0.1 lb ai/A. PHI 14 days. REI 12 hr. Do not exceed 0.1 lb ai/A per application or 0.3 lb ai/A per season. Minimum application interval is 21 days. Group 3A insecticide.
- imidacloprid/bifenthrin (Brigadier, Swagger) by ground or air at 0.06 to 0.20 lb ai/A. PHI 28 days. REI 12 hr. Do not apply more than 0.1 lb ai/A of imidacloprid or more than 0.1 lb ai/A of bifenthrin per application. Do not apply more than 0.30 lb ai/A of any bifenthrin formulation or 0.30 lb ai/A of any imidacloprid formulation per season. Group 4A/3A insecticides.
- pyrethrins/azadirachtin (Azera) at 0.013 to 0.0044 lb ai/A azadirachtin/0.014 to 0.048 lb ai/A pyrethrins. PHI 0 days. REI 12 hr. Apply when pest populations first appear. Reapply every 5-7 days as needed up to 10 times per season. Do not apply more than 0.050 lb ai/A pyrethrins per season. Some formulations are OMRI-listed for organic use. Group 3A insecticide.
- spinetoram (Delegate WG) at 0.039 to 0.063 lb ai/A. PHI 1 day. REI 4 hr. Target eggs and small larvae. Allow at least 4 days between applications. Do not make more than two consecutive applications of group 5 insecticides. Do not make more than 3 applications per season. Do not apply more than 0.305 lb ai/A per season. Group 5 insecticide.