Evaluation of liquid baits against field populations of the longlegged ant (Hymenoptera: Formicidae)

An evaluation of several insecticides, namely, 0.01% fipronil, 0.05% indoxacarb, and 2% boric acid in liquid bait formulations were carried out against field populations of the longlegged ant, Anoplolepis gracilipes (Fr. Smith) (Hymenoptera: Formicidae). The baits were formulated in brown cane sugar solution (50%, wt:wt) and placed in an experimental bait station. Each bait was evaluated against populations of A. gracilipes at four buildings. Fipronil, indoxacarb, and boric acid were effective against A. gracilipes, with > 90% reduction of workers within 3 d posttreatment. Total reduction (100%) was achieved within 7 d for fipronil, 14 d for indoxacarb, and 56 d for boric acid. The performance of fipronil and indoxacarb baits did not differ significantly (P > 0.05) in all postbaiting sampling intervals. Reduction of A. gracilipes resulted in an increase in other ant species [Monomorium pharaonis (L.), Monomorium floricola (Jerdon), Monomorium orientale Mayr, Monomorium destructor (Jerdon), Tapinoma indicum Forel, Pheidole sp., and Camponotus sp.] at the baited locations.