Effect of Pre-Treatment and Histological Alterations Induced by Sub Lethal Dose of Lufenuron on Both Chlorpyrifos and Imidacloprid Efficacy on Cotton Leaf Worm, Spodoptera littoralis (Bosid.)

Hassan, Noura A.; Morshedy, M.; Shaker, N.

doi:10.21608/jppp.2017.46370

Effect of Pre-Treatment and Histological Alterations Induced by Sub Lethal Dose of Lufenuron on Both Chlorpyrifos and Imidacloprid Efficacy on Cotton Leaf Worm, Spodoptera littoralis (Bosid.)

Document Type : Original Article

Authors

Faculty of Agriculture - Alexandria University - El Shatby

10.21608/jppp.2017.46370

Abstract

Chlorpyrifos and Imidacloprid are belongs to two main groups of insecticides that are widely used in insect control. Many researches had been discussed the effect of both groups on non-target organisms and the environment. So, it necessary to reduce the used doses of this groups to save the environment. The effect of pre-treatment with lufenuron (chitin synthesis inhibitor) at sub lethal dose (LD₂₅) on the efficacy of Chlorpyrifos and Imidacloprid on Spodoptera littoralis was studied using topical application method. The toxicity of both Chlorpyrifos and Imidacloprid increased after 24hrs of pre-treatment with LD₂₅ of Lufenuron by 55 and 250 times for Chlorpyrifos and Imidacloprid, respectively compared with the toxicity of each compound alone. Histological studies showed that the treatment of 2^nd instar larvae with LD₂₅ of Lufenuron caused obvious separation of the hypodermis layer from the endocuticle, abnormalities in the epicuticle morphology , rupture in muscles, irregular and great disintegration of cuticle and hypodermis. In-vivo interaction of LD₂₅ values of Chlorpyrifos, Imidacloprid and Lufenuron with Alkaline and Acid phosphatase caused significant increase in the activity of Alkaline phosphatase while Acid phosphatase activity was significantly decreased in all treatment.