Toxicity of sodium fluoroacetate and zinc phosphide wheat grain baits to Microtus guentheri and Meriones tristrami

Whole wheat grains impregnated with 0.02, 0.05 and 0.2% sodium fluoroacetate, and 2% zinc phosphide, were offered to series of single caged individuals of Microtus guentheri and Meriones tristrami. In most cases the sodium fluoroacetate treated baits were well accepted by both species. The acceptance of the zinc phosphide-treated bait was partial in all the series tested. The approximate LD50 ranges of sodium fluoroacetate are between 0.24 and 0.43 mg kg−1 for M. guentheri, and, perhaps, for the jirds too, and for zinc phosphide—between 32.6 and 58.8 mg kg−1 for M. tristrami, and a similar value, more or less, for M. guentheri.