Susceptibility of house rat, Rattus rattus Linneaus against difethialone treated baits in laboratory

Abstract

The house rat Rattus rattus is one of the most important vertebrate pests constituting about 7O-75 per cent of the rodents in houses and godowns. lt inflicts heavy losses to stored food grains, storage structures, guny bogs, cloths and utensils besides contaminating the food. Difethialone, a second-generation anticoagulant rodenticide was extensively evaluated in laboratory for its management. Three concentrations of difethialone, viz.,0.00125, 0.0025 and 0.005 per cent were evaluated for three exposure (one, two, three days) periods under choice and no-choice condition. ln no-choice test single day exposure yielded cent per cent mortality of the test rodents at 0.0025 and 0.005% conc. within 3-I0 and 2-9 days, respectively, whereas increase in feeding period (2 and 3 days) reduced the mean days to death (4.40- 5.40 days)' ln choice test the consumption of plain and poison bait was at par for all the three-test concentration and exposure periods. At the lower test concentration (0.00125 %), the mortality after I ,2 and 3 days feeding of poison bait was 50, 80 and 90 per cent, however, at 0.0025 and 0.005% concentration, 80% of the test animals succumbed to the anticoagulant in a single day exposure. Thus, the present findings proved that difethialone is a fairly palatable and a potent rodenticide for the control of house rat.