Biochemical and Toxicological Studies of Some Pesticides on Cotton leafworm ( Spodoptera littoralis)

Abstract

The present study is to through light on role of some insecticides (chemical insecticides (a.i. chlorphyrifos) Dursban® 48% EC, spinosyns group (a.i. spinosad) Tracer® 24% SC and insect growth regulator (a.i. lufenuron) Match® 5% EC) against insect attacking cotton cultivation Spodoptera littoralis under Egyptian conditions. The toxicological effects and biochemical analysis carried out against laboratory strain of target insects after 24 and 72 hours. Toxicity of the three insecticides chlorphyrifos, spinosad and lufenuron were tested against the 2 nd instar larvae of the cotton leafworm, spodoptera littoralis. The results showed that lufenuron was more effective on the 2 nd instar larvae than chlorphyrifos and spinosad. The LC25 values for lufenuron, chlorphyrifos and spinosad were 0.0005, 2.21 and 8.1 ppm, respectively. The biochemical study used for tested insecticides at LC25 on some biocomponents namely acetylcholinesterase (AchE), glutathione-s-transferase (GST), chitinase, phenoloxidase, aspartate (AST) and alanine (ALT) aminotransferases, α-esterase (α-EST), total protein and protein gel electrophoresis for laboratory strain were investigated. The tested chlorphyrifos and lufenuron were significantly increased (AchE). Spinosad was significantly decreased (GST) and phenoloxidase. Spinosad and lufenuron significantly increased (α-EST) and (chitinase) (ALT). Chlorphyrifos caused significantly decreased on α-esterase and total protein and (AST). Lufenuron significantly decreased total protein and phenoloxidase. Spinosad showed insignificant increase in (AchE) and total protein (levels). Chlorphyrifos decreased both of phenoloxidase and (ALT) levels insignificantly and increased the levels of (GST) and chitinase, while lufenuron, recorded insignificant decrease in GST levels. The total body proteins of 2 nd instar larval of S. littoralis treated with LC25 of insecticides performed by SDS-PAGE. Control and different treatments were separated into 56 different bands according to their relative frequencies (Rf values), and molecular weights (MW). Samples of electrophoresis were carried out for three different insecticides namely chlorphyrifos, spinosad and lufenuron which used to treat insects. The treatment with insecticides on protein gel electrophoresis led to detection of new bands, and disappeared some bands in comparison to control. It is concluded that treatment with insecticides have strong efficacy on the soluble protein in the body of insects.

Biochemical and Histological Responses of Red Palm Weevil, Rhynchophorus ferrugineus Exposed to Sub-lethal Levels of Different Insecticide Classes

“…These results agree with (Assar et al, 2016) by emamectin and spinetoram, and hexaflumuron against the 4th instar larvae of Spodoptera littoralis and with (Abd-El-Aziz, 2014; Amin and Fahmy, 2011) using spinetoram reduced both GOT and GPT of Spodoptera littoralis. Also, Spinosad and lufenuron significantly increased the ALT of Spodoptera littoralis (Magdy et al, 2019).…”

“…The methomyl trend in insects was also the same in the Spodoptera littoralis larvae with emamectin benzoate, abamectin and spinosad (Megahed et al, 2013). Chlorpyrifos decreased (ALT) levels insignificantly of Spodoptera littoralis (Magdy et al, 2019). On the other hand, spinosad treatments induced a significant inhibitory effect on transaminases (ALT and AST) activities.…”

Larvicidal activity assessment for anticholinesterase insecticides against laboratory and field strains of Egyptian cotton leafworm, Spodoptera littoralis (Boisduval) (Lepidoptera: Noctuidae)

“…Chemical control strategy for the Egyptian cotton leafworm through the utilization of synthetic insecticides represents the most effective tool. However, the high rate of application raises the resistance to most of the presently used insecticides [1][2][3] . Anticholinesterase insecticides are one among the foremost widely applied agrochemicals in crop protection programs despite their harmful effects on the environment and therefore the human health.…”