MONITORING:
Symptoms of adult feeding can be seen on leaf margins beginning in June. The nocturnal adults can be spotted at night with a flashlight. Traps can also be made by placing fold of burlap around the base of the plant, or by creating a pitfall trap by burying a paper cup at soil level. Traps should be checked at least twice a week. It is important to determine when the first adults are emerging so that control measures can be taken before they begin to lay eggs (2-3 weeks after emergence).
CONTROL:
Chemical control
The key to controlling black vine weevils is to eradicate the adults before they begin egg laying. It is important to use a chemical with residual properties as the adults do not feed every night. Acephate, bifenthrin, cyfluthrin, and permethrin can be used for chemical control of adults and should be applied 3 weeks after the adults are first seen, then again tree weeks later. Chemical applications should be made late in the day, as the adults are nocturnal. Imidacloprid and bifenthrin may also work on the grubs, but must be applied early before grub damage occurs. As with any pesticide, be sure to follow labels directions.
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