Toxicity of Herbal Insecticides on Aphis gossypii and Its Natural Enemy (Aphidius colemani) in Laboratory and Greenhouse Conditions

This study was carried out to evaluate the toxicity of herbal and chemical insecticides on various stages of cotton aphid (aphis gossypii) and parasitoid wasp (aphidius colemani). The experiment was done in laboratory and greenhouse as a factorial experiment in completely randomized design with three replications. Two herbal insecticides (palizin and tondexir), one chemical insecticide (imidacloprid) and control (water) were used in 0.3, 0.6, 0.9, and 2.7 ppt (part per thousands) doses on cucumbers. Interaction effect of pesticides and concentrations on aphid and aphidius wasp were significant highly (P<0.01). Mortality of aphid was increased by increasing concentration and both imidacloprid and tondexir (2.7ppt) caused the highest mortality (92.1% and 91%). Laboratory results were similar to greenhouse results and imidacloprid and tondexir (2.7ppt) had the highest effect whereas palizin (0.3ppt) had the least. Various concentrations of imidacloprid had the highest effect on aphidius wasp and were significantly different from each other and also from other pesticides. Mentioned herbal insecticides are recommended to replace chemical insecticides in integrated pest management plans.