سمية بعض أنواع المساحيق الخاملة ضد خنفساء اللوبياء العادية Callosobruchus maculatus (F.) تحت الظروف المخبرية

Inert dusts toxicity of kaolin, silica and zeolite were tested against adults of cowpea seed beetle Callosobruchus maculatus (F.) (Coleoptera, Bruchidae) using five concentrations 5, 10, 20, 40 and 80 g/kg of cowpea seed. The study was carried out in an incubator at fixed temperature and humidity at the Biotechnology Research Center, Al-Baath University. Readings were taken 24, 48 and 72 h after treatment, and corrected mortality rates and LC50, LC90, LT50 and LT90 values were calculated. Results showed that mean of corrected mortality rate after 24 hours at concentrations of 5, 10, 20, 40 and 80 g/kg of seed were 11.34, 35.73, 42.45, 47.72 and 53.71%, respectively, with significant difference at P=0.01. Mortality rates for kaolin, silica and zeolite powders were 46.18, 38.46, 29.93%, respectively, with significant differences at P=0.01. The LC50 and LC90 values were 3.285 and 7.303 g/kg for Kaolin, 7.607 and 25.176 g/kg for Silica and 8.909 and 151.902 g/kg for Zeolite 48 h after treatment. The LT50 and LT90 values were 23.03 and 30.43 h for kaolin, 24.00 and 40.37 h for silica and 31.23 and 68.04 h for zeolite at 40 g/kg. Kaolin powder showed higher toxicity and minimal mortality time compared to the other products. Keywords: Toxicity, powder, inert dusts, kaolin, silica, zeolite, cowpea seed beetle, Callosobruchus maculatus