Field Evaluation of Aerial Applications of Hydramethylnon and Metaflumizone to Control the Red Imported Fire Ant, Solenopsis invicta and Related Ant Species (Hymenoptera: Formicidae)

Hydramethylnon fire ant bait has been the industry standard for controlling red imported fire ants (RIFA) since being introduced to the market. It can be compared to new baits, and used to evaluate different aerial application techniques, such as the "skipswath" method. Two baits, hydramethylnon and metaflumizone, and a skipped-swath application method were evaluated through observations of the activity levels of RIFA in mounds, and when foraging. The effects of RIFA on other ant species were determined by suppressing RIFA populations with insecticide baits, and then using two different sampling methods, including a vibrated wire placed in RIFA mounds to determine the number of ants responding, and the use of baited (carbohydrate and protein) vials to determine forager population levels of several ant species through time. The results indicated control of RIFA with either hydramethylnon or metaflumizone from 61 to 180 d post-treatment. Native ants, such as Dorymyrmex spp., were found in higher numbers once RIFA populations were reduced, indicating that the two ant species compete for resources, while other ants such as Paratrechina spp. were unaffected.