Monitoring of Pesticides Resistance in Spodoptera littoralis from Some Governorates of Egypt: A Pilot Study Dependent on Biochemical Responses

Document Type : Original Article

Author

Agriculture Research Center, Central Agricultural Pesticides Laboratory, Giza, Egypt

Abstract

Resistance ratio (RR) and biochemical alterations for seven bioinsecticides against Spodoptera littoralisin two Egyptian governorates were assayed. The values of LC50 have fluctuated from 42.9 to 0.01 ppm for the strain of Menofia governorate, but in Gharbia governorate the values have fluctuated from 0.004 to 0.1 ppm. On the other hand, RR for the examined insecticides: Radeiant®, Agrine®, DipelDF®, Dipel 2X®, Brotecto®, Radecal® and Biotect® during 2019 cotton season. Resistance ratio (RR) for seven insect growth regulators (IGR's) Demelen®, Tobron®, Demeron®, Kabres®, Kalegron® and Match® against S. littoralis were also assayed. LC50 values in Menofia governorate have fluctuated from 0.014 to 2.9 ppm, and RR values were very low. Finally these compounds still effective against S. littoralis during 2019 season. Alterations were induced in enzymes: acetylcholinesterase (AChE), glutathione-S- transferase (GST), acid and alkaline phosphatase as well as total protein, to field strains, with respect to laboratory strains. From all findings, the coupling of LC50, RR values and-related enzymes may recognize a reliable tool to assess S. littoralis resistance. Moreover, bioinsecticides and IGR.s were very effective to control leafworm in cotton fields.

Keywords