Protection of stored plant products using chlorophacinone against rodent pests

Abstract

Apart from some preventive measures advisably taken during construction of storage facilities or at the time of product storage, treatments with chemical rodenticides are the most widely practiced method of controlling commensal rodents. Their control in storage facilities is normally carried out after animal presence has been observed, and treatments from early autumn onwards throughout the season provide the best effect. The aim of this paper is to present the effects of rodent control using baits with less content am chlorofacinon than recommended, to the protection of stored plant products. The experiments were set up using the relevant OEPP/EPPO method. A ready for use (RB) paste bait formulation was used with different contents (0.005% and 0.0075%) of the active ingredient chlorophacinone. Baits were laid in boxes along rodent routes, underneath pallets with sacs and in places where major damage had been observed. Baits for house mouse were placed at a rate of 10-20 g per 1-3 m, while 30-50 g of bait for brown rats were laid at specific points. Daily bait intake was monitored over a period of ten days and the portions were replaced with new ones as needed. Placebo baits were laid in identical boxes for four days before the experiment began. The abundance of house mouse was estimated based on the highest and lowest daily intake of bait divided by the species? daily requirement. Mice presence was monitored over the next 20 days. Rodenticide efficacy was calculated using Abbott?s formula. The data in this experiment show that chorophacinone contents of 0.005% and 0.0075% in RB baits had no effect on the palatability and bait efficacy in controlling house mouse and brown rat indoors. The average efficacy of chorophacinone was 87-93% against house mouse and 90-100% against brown rat.