Field Evaluation of DRC-714 for Deer-Mouse Control in a Redwood Habitat

Direct seeding of conifers in western America often results in considerable seed loss to rodents, principally deer mice (Peromyscus spp.). An operational test of the toxicant DRC-714 (0, 0, bis [p-chlorophenyl] acetimidoylphos-phoramidothioate) was conducted January 11-February 3, 1966, on deer mice (Peromyscus maniculatus rupidus Osgood) in a redwood type in Humboldt County, California. Wheat bait treated with DRC-714 at the one-seed-lethal concentration was distributed by helicopter on three 5-acre plots and a 95-acre buffer zone at the rate of ½ pound per acre. Pre- and post-treatment censuses indicated a 98-percent reduction in the number of deer mice on the three 5-acre treated plots, and very little change on the 5-acre control plot nearby.