Evaluation of the use of diatomaceous earth to control Sitophilus zeamais in rice husks

Abstract

Rice is among the most consumed and obtained grains in the world, being responsible for feeding around 2.5 billion people, but much is lost due to the attack of insects in storage. Based on this, the objective is to evaluate the use of diatomaceous earth in paddy rice grains when infested by adults of Sitophilus zeamais. Grains with an initial moisture content of 12 and 14% were used, each moisture being treated with doses of 0, 500, 1500 and 2500 g t-1 in two infestation periods: 1 hour and 15 days after application. Each dose was composed of five replicates containing 100 g of grains and 20 adult adults, for each moisture content and infestation period. At 30 and 60 days after each infestation, the mortality and emergence of Sitophilus zeamais were analyzed. Loss of grain weight and moisture content were verified only at 60 days. Grains free from treatment lower mortality values ​​of Sitophilus zeamais, differing statistically from the others, regardless of the infestation periods. Regardless of the initial moisture content and infestation period, doses of diatomaceous earth of 1500 and 2500 g t-1 mortality rate of Sitophilus zeamais between 98 and 100%. All sinuosities final moisture content below 12%. Greater weight losses were observed in grains with higher initial moisture content. In this way, it can be conquered that the diatomaceous earth has a satisfactory action in the control of S. zeamais in rice husks when they enter hygroscopic balance below 12%.