APICULTURE AND SOCIAL INSECTS Formic Acid Treatment for Control of Varroa destructor (Mesostigmata: Varroidae) and Safety to Apis mellifera (Hymenoptera: Apidae) Under Southern United States Conditions

The efÞcacy of a formic acid pad formulation was Þeld tested for control of the honey bee parasitic miteVarroa destructorAnderson & Trueman in Florida and Texas. This pad formulation gave 39.8 11.1% control at the end of a 6-wk treatment period,which did not signiÞcantly differ from the initial sample date. Coumaphos treatment provided poor control (38.4 11.1%) over the 6-wk period, conÞrming reports of coumaphos resistance in the region. Under relatively warm winter conditions in southern Texas, formic acid causedmortality of developing eggs and brood. If resistance by V. destructor to the two acaricides registered for its control in the United States continues, the formic acid pad could provide an alternative compound to use as part of an integrated pest management approach. Given the low control seen in this trial, however, modiÞcations of application technology would seem necessary.