Side Effect of Some Insect Growth Regulators (IGRs) on the Associated Predators of Cotton Leaf Worm, Spodoptera littoralis ( boisd.) In Cotton Fields

Abstract

Side effect of six Insect Growth Regulators (IGRs) (lufenuron, teflubenzuron, flufenoxuron, chlorfluazuron, methoxyfenozide and chromafenozide) used against the cotton leafworm, Spodoptera littoralis (Boisd.) in cotton field was studied on Coccinellidae spp, Chrysoperla carnea and true spiders predators under field conditions during 2013 and 2014 cotton seasons. The obtained results showed that the numbers of all tested predators were decreased after three days of IGRs application and return to increase after seven days in the two seasons. Chlorfluazuron was the most toxic against all tested predators. The percent efficacies of Chlorfluazuron were 37.07, 33.60 and 24.90% for Chrysoperla carnea, true spiders and Coccinellidae spp, respectively. While, flufenoxuron (13.89%), teflubenzuron (22.60%) and methoxyfenozide (22.13%) were the lowest toxic against Coccinellidae spp. C. carnae and true spiders, respectively. These results recommended that chlorfluazuron was not suitable during the peak of natural enemies.