Evaluation of a Hydrogel Matrix for Baiting Western Yellowjacket (Vespidae: Hymenoptera).

Baiting is an effective method to manage Vespula spp. yellowjacket (Hymenoptera: Vespidae) populations without having to locate and treat nests. Here, we assessed the utility of a commercially available polyacrylamide hydrogel as an alternative bait material for yellowjacket baiting. The experimental bait (hereafter referred to as 'hydrogel bait') consisted of diluted chicken juice (from canned chicken meat) and fipronil (0.025%, wt/wt) absorbed into granular polyacrylamide hydrogel particles. Three separate 24-h baiting trials were conducted at two different field sites with the western yellowjacket, Vespula pensylvanica (Saussare), as the target species. The monitoring data from pre- and posttreatment periods indicated that baiting with polyacrylamide hydrogel baits provided ≈74-96% reduction in the foraging activity of V. pensylvanica during its active season. In addition to their ability to absorb large quantities of aqueous bait containing phagostimulants and toxicants, the hydrogels' tactile resemblance to fresh meat upon hydration makes them a promising option as a non-meat material for delivering small amounts of insecticides to yellowjacket populations in a highly targeted manner.