Research and IPM

Evaluate various baits for preference by ants and determine if preference varies in relation to season.

Evaluate the efficacy and impact of baits on populations of F. perpilosa under field conditions.

Test a granular ant bait impregnated with the insect growth regulator, pyrproxyfin, against two fire ant species, Solenopsis molesta and S. aurea.

Evaluate the immediate and long-term effect upon populations of S. molesta and S. aurea when bait is applied post-harvest.

During 2003, we tested two EPA approved bait stations and a prototype station developed in our laboratory. F. perpilosa foraged equally from each of the bait stations tested. The commercial bait stations that we tested require a large amount of time to fill and distribute throughout a vineyard, and this may discourage growers from adopting their use. Our prototype station is designed so it can be easily filled and distributed through a vineyard from a moving vehicle, such as an All Terrain Vehicle.

Our data indicates that both hydramethylnon and imidacloprid are effective toxicants against F. perpilosa, however other available toxicants may provide more effective control. During 2003 we conducted a series of laboratory toxicity experiments in which thiamethoxam, Tim-bor® (disodium octaborate tetrahydrate), or boric acid were dissolved in 20% sucrose water at various concentrations and presented to F. perpilosa. Thiamethoxam is effective against F. perpilosa at a concentration of 0.0001% wt./wt. while Tim-bor® and boric acid are effective at concentrations of 0.25 and 0.5% wt./vol. respectively. Field trials are planned in which these toxicants will be formulated with the anchovy bait in lieu of imidacloprid.

During 2003 we also tested two commercially available ant bait stations and a prototype bait station developed in our laboratory. Ant baits delivered in bait stations can significantly reduce their registration requirements and can extend their efficacy by protecting the bait toxicant from photodegradation.

F. perpilosa foraged from each of the bait stations tested. However, the commercial bait stations that we tested require a large amount of time to fill and distribute throughout a vineyard; for this reason their use may be economically prohibitive. Our prototype station, however, is designed in order that it can be easily filled and distributed through a vineyard from a moving vehicle, such as an All Terrain Vehicle.

Anchovy baits were the most highly preferred over the duration of the experiment. The NiBan and Maxforce baits were not collected by F. perpilosa in significant amounts. Niban, which consists of weatherized cornhusk and 5% boric acid, did however attract a local fire ant species, Solenopsis molesta (Westwood). Maxforce, which consists of silkworm pupae and 1% hydramethylnon, was the only protein-based bait in the test. Our preliminary research with other species of Formica suggested that Maxforce might be attractive to F. perpilosa. No change in preference occurred over the experimental period.

A trial to test the efficacy of anchovy bait with 0.005% and 0.05% imidacloprid, and Maxforce against F. perpilosa began in Late August 2002. Both anchovy with 0.05% imidacloprid and Maxforce reduced the number of foraging ants by 10 days after treatment (DAT). Maxforce reduced the overall number of foragers below that of the control plot for up to 122 DAT.