Joint action of two novel insecticides mixtures with insect growth regulators, synergistic compound and conventional insecticides against spodoptera littoralis (Boisd.) Larvae

Abstract

In laboratory study the interaction between two recently developed insecticides (pyridalyl and spinetoram) were combined at different mixing' ratios in binary mixtures with eight compounds including three conventional insecticides (chlorpyrifos-E, methomyl and deltamethrin), two IGRs (hexaflumuron and pyriproxyfen) and three synergists compounds (Pepronyl butoxide, sesame oil and oleic acid) and investigated against S. littoralis, 4th instar larvae. Based on co-toxicity coefficient, both insecticides (pyridalyl and spinetoram) response positively when mixed with chlorpyrifos-E and exhibited remarkable potentiation effect at most tested mixing ratios within 24 and 48 h post treatment. On the other hand, slight synergism was only recorded for pyridalyl/pyriproxyfen mixtures at 9:1 and 4:1 while similar trend was also recorded at 9:1, 4:1 and 1:1 of pyridalyl/hexaflumuron mixtures whereas no synergism was almostly recorded for spinetoram/IGRs mixtures. In contrast, the three compounds (pbo, sesame oil and oleic acid) exhibited highly considerable synergism at all tested mixing ratios with pyridalyl while sesame oil and oleic acid evoked remarkable synergism only in their binary mixtures with spinetoram. © 2013 Academic Journals Inc.