Management of a mound-building Ant, Lasius neoniger Emery, on golf putting greens and tees using delayed-action baits or fipronil

The ant Lasius neoniger Emery can be a serious pest when its nesting and mound-building activities occur on golf putting greens and tees. Controlling turf-infesting ants is difficult because conventional insecticides usually fail to eliminate the subterranean queen. We compared the attractiveness of commercial and experimental ant baits to L. neoniger workers, and we evaluated baits containing novel, delayed-action toxicants for selective control of L. neoniger on creeping bentgrass, Agrostis stolonifera L., golf tees. Efficacy of nonbait granular fipronil, a new phenyl pyrazole insecticide, also was evaluated. In choice tests, protein-based baits were more readily taken than baits containing sugar- or oil-based attractants. Abamectin-, hydramethylnon-, or spinosad-based baits significantly reduced numbers of ant mounds and nests when applied either as spot or broadcast treatments. Two commercial baits, Advance Granular Carpenter Ant Bait, containing 0.011% abamectin B₁, and Maxforce Ant Killer Granular Bait, containing 0.9% hydramethylnon, were especially effective. Spot-treatment with either of these baits, using 1 g of bait per mound, eliminated 88 to 97% of the mounds within 3 d. Broadcast application of fipronil (0.028 kg a.i. ha^-1) on heavily infested, sand-based creeping bentgrass putting green turf in May provided ≃80% reduction of ant mounds at 7 d after treatment and 86% reduction at 60 d.