Testing the attractiveness and efficacy of baits for the monitoring and control of the thief ant, Solenopsis papuana

Solenopsis papuana is one of the few invasive ant species that have widely infiltrated undisturbed mesic and wet forests with high population densities in Hawaii. This may be problematic since most endemic Hawaiian insects are limited to mountain forests. Research investigating the potential impact of S. papuana on native arthropod species and food webs is currently in progress, which has required the development of experimental monitoring and control methods. Four non-toxic monitoring baits (corn syrup, SPAM, tuna and corn syrup blend, and peanut butter) and five ant pesticides (Advion Fire Ant Bait, Amdro Ant Block, Extinguish Plus, MaxForce Complete Brand Granular Insect Bait, and Siesta) were tested for attractiveness in choice tests at two field locations (Lyon Arboretum and Pahole Natural Area Reserve). Amdro Ant Block and Siesta, were also tested for efficacy in a field plot experiment. It was determined that S. papuana is most attracted to SPAM and peanut butter monitoring baits at both locations. Relative attractiveness of the ant pesticides depended on location: there was no significant difference among the baits at Pahole NAR, but Amdro and Extinguish were the most attractive at Lyon Arboretum. In the efficacy test, Amdro has reduced numbers of S. papuana more effectively than Siesta to date. Although eradication of S. papuana is likely not feasible, these methods may be useful for controlling population densities in localized areas of interest or concern.