The Attractiveness of Toxic Bait is not Always Accompanied by Increased Mortality in Laboratory Colonies of Argentine Ants,Linepithema humile(Hymenoptera: Formicidae)

Abstract

The Argentine ant, Linepithema humile, is a globally known invasive ant species responsible for widespread biodiversity and economic loss, thus there is a growing need to control and preferably locally eradicate these ants from invaded environments and households. We evaluated the attractiveness and toxicity of six commercial baits containing hydramethylnon, imidacloprid and pyriproxyfen targeting Argentine ants, and differing in bait formulation. Hydramethylnon granular baits were most effective, killing workers (85–100% worker mortality) and queens (63–75 %) in the laboratory within 24 h. Workers were most attracted to and consumed the most of the imidacloprid gel bait, but, contrary to previous studies, mortality on this bait was low. The pyriproxyfen bait was least effective in killing workers, as was expected, and was the least consumed of all baits.We advocate the use of a fine granular hydramethylnon formulation for the effective control of Argentine ants. The attractiveness and consumption of the ...