Proceedings of the Vertebrate Pest Conference

Two field trials were conducted to determine the effectiveness of anticoagulant baits in pocket gopher (Thomomys bottae) control. In the first trial, burrow systems were baited once with chlorophacinone 0.005% on rolled oats and embedded in paraffin to form a wax block. The systems were arranged in a one systemwide line bordering a clean vineyard. Infestation of the vineyard was prevented for 2 months; after that, gophers did bypass the barrier of treated systems and entered the vineyard. In the second trial two anticoagulant baits, chlorophacinone 0.005% on rolled oats and embedded in paraffin, and diphacinone 0.0052% on various grains and embedded in paraffin, were compared to strychnine-treated 0.29% whole wheat grain bait. Fifteen individual gopher systems were baited in each of three replications and monitored for 8 1/2 months. Both of the anticoagulant paraffin block-type baits achieved significantly greater long-term gopher control than the strychnine-treated loose grain bait.