Increasing acceptance and efficacy of zinc phosphide rodenticide baits via modification of the carbohydrate profile

Toxicant coated grain-based baits are widely used to control rodent pests throughout the world, but where alternative food sources are available, bait acceptance and efficacy are often less than optimal. In an attempt to develop baiting strategies to increase bait acceptance and efficacy of zinc phosphide-coated baits, a sugar-enhanced rolled oat based zinc phosphide bait was evaluated. With pre-baiting, 100 and 60% mortality was achieved for California and Belding's ground squirrels, respectively. A series of two-choice tests with a variety of potential bait matrices indicated that rolled oats was a desirable base matrix for both species but the lecithin sticker negatively impacted bait acceptance by Belding's ground squirrels.