Evaluation of Toxicity and Acceptability of Difethialone Treated Baits in Indian Desert Gerbil, Meriones hurrianae Jerdon

Abstract

Difethialone, a second generation anticoagulant rodenticide was assessed for its susceptibility and acceptance in baits against Meriones hurrianae. Fresh loose bait containing difethialone (25 ppm) prepared in pearl millet grain resulted in 100 per cent mortality during no-choice test in one day feeding, Mean period to death was 5.90 days with an average poison intake of l.l7 + 0.09 mg/Kg/day. Poison bait acceptability was fairly good as observed by non-significant differences in the consumption pattern of poisoned and plain bait in choice test. Single day exposure of difethialone (0.0025%) accounted for 70 per cent mortality of test animals from 5 to I I days (Av. 7.86), whereas, two days exposure yielded 90 per cent mortality in choice test. The compound did not induce bait shyness in the surviving test animals. The death of the gerbils was due to excessive bleeding through nose, anal aperture and ears. These trials revealed that difethialone is a potent rodenticide for containing this predominant rodent species inhabiting the Indian arid agro-ecosystem