Rate of removal of fenoxycarb (Logic(R)) fire ant bait by red imported fire ants (Hymenoptera: Formicidae) from treated pastures

Field studies were conducted in Vero Beach, FL, in November 1993 and 1994 to determine the rate of removal of Logic(R) fire ant bait by red imported fire ants, Solenopsis invicta Buren, from treated improved pastures of bahiagrass, Paspalum notatum Fluegge. Logic(R) fire ant bait was applied at the maximum label rate of 1.68 kg/ha (16.8 g ai/ha). In 1993, fire ants had removed approximately 35% of the granules by 4 h after application and about 67% by 12 h. By 24 h, 82% had been removed. By the last count (48 h after application) about 95% had been removed. In 1994, the granules were removed slightly faster, with about 60% removed by 4 h and 92% by 24 h after application. Nearly 97% of the granules had been removed by the last count (30 h after application). In 1993, several mounds of the ant, Dorymyrmex bureni Trager, were found in the test area while in 1994 only red imported fire ant mounds were present. The results indicate that Logic(R) fire ant bait is found and harvested very rapidly by fire ant workers under favorable foraging conditions and that a dose which will provide effective population reduction can be obtained in 12 to 24 h after application at 1.68 kg/ha. Additionally, with its low use rate, specificity to certain insects and rapid removal by fire ants, Logic(R) fire ant bait when used according to label poses minimal risk to non-target organisms.