CONTROL OF MAIZE WEEVIL THROUGH HEAT TREATMENT

Abstract

The maize weevil, Sitophilus zeamays Mots. (Coleoptera: Curculionidae), is a major pest of maize (Zeamays L.) and other stored grains in Brazil. The aim of this study was to evaluate the mortality of adult insects of themaize weevil in maize grains subjected to low and high temperatures. Temperatures of 3, 6, 9, 60, 70 and 80 ºC wereused and 500 g of corn infested with 30 insects.. Assessments of mortality in the treatments using 3, 6 and 9 ºC wereperformed at 5, 10, 15, 20, 25 and 30 days after infestation and for treatments at 60, 70 and 80 ºC, every thirty minutesuntil reaching 100% mortality. Temperature of grain mass in the cold treatment and temperature of mass, weight lossesand moisture in the heat treatments were determined. It can be concluded that the heat treatment of stored grain is aninteresting alternative to control pests during storage. At 3 ºC, 100% mortality of insects can be achieved in less than30 days of exposure. At high temperatures, 100% mortality can be achieved quickly, in minutes. As higher the heatingtemperature and shorter the exposure time to heat,, smaller were weight losses and grain moisture.

Keywords

• physical methods of control
• stored grain pests
• Sitophilus zeamays