THE BAIT SURCHARGE PROGRAM: RESEARCH IMPROVES ZINC PHOSPHIDE USE FOR VOLE CONTROL IN ALFALFA

Authors

Ray T. Sterner, United States Department of Agriculture, Animal and Plant Health Inspection Service, Wildlife Services, National Wildlife Research Center

Date of this Version

January 1998

Abstract

This paper describes several unexpected benefits of rodenticide-registration research funded by The California Bait Surcharge Program. An enclosure-type study was conducted to determine efficacy of single, pre- and test-bait broadcasts (10 lb./ac.) of 0% and 2% zinc phosphide (Zn₃P₂, CAS #1314-84-7) steam-rolled-oat (SRO) groats to control voles (Microtus spp.) in alfalfa (Medicago sariva). Unexpected research spinoffs resulted from the use of: 1) eight randomly-located, sieved-dirt plots per enclosure to monitor bait distribution, bait removal, and rodent/avian (non-target) activity; 2) a bait-weathering plot and bait-sample analyses to monitor Zn₃P₂ biodeterioration; and 3) a C⁺⁺-language program to derive theoretical benefit-cost ratios associated with Zn₃P₂-bait broadcasts.