ZINC PHOSPHIDE−A NEW LOOK AT AN OLD RODENTICIDE FOR FIELD RODENTS

Abstract

Of the many toxicants tested to control field rodents, compound 1080 (sodium monof1uoroacetate), strychnine alkaloid, and zinc phosphide are the only effective single-dose rodenticides currently available. Considering the federal requirements for use in food and feed crops, zinc phosphide is the toxicant most likely to be registered for field rodent control. It is generally well accepted by rodents, is relatively safe for nontarget species, and does not seriously contaminate the environment. It is already registered, with an established tolerance, for use in one food crop (Hawaiian sugarcane). The Bureau of Sport Fisheries and Wildlife is conducting research, some in cooperation with other agencies, to register zinc phosphide for controlling: prairie dogs (Cynomys ludovicianus) in shortgrass rangeland; jackrabbits (Lepus californicus) along cropland-rangeland borders; cotton rats (Sigmodon hispidus), rice rats (Oryzomys palustris), black rats (Rattus rattus), and Florida water rats (Neofiber aileni) in Florida sugarcane; ground squirrels (Spermophilus spp.) and meadow voles (Microtus spp.) in alfalfa, sugarbeets, artichokes, and rangeland.