Changes in detoxifying enzymes and carbohydrate metabolism associated with spinetoram in two field-collected strains of Spodoptera littoralis (Biosd.)

Abstract

This study was conducted to investigate the biochemical defensive mechanisms in larvae of S. littoralis (Biosd.) (Lepidoptera: Noctuidae) collected from cotton fields in two Egyptian Governorates (Kalyobia and Behira), sprayed with spinetoram as well as its impact effect upon carbohydrate metabolism. The role played of spinetoram on different major defensive enzymes like glutathione S-transferases (GSTs) , non specific esterases and acetylcholinesterase(AChE) was discussed. It seems that these enzymes are not greatly involved in the detoxifying process of spinetoram except a marked over production of AChE reached up to 18.7% as well as the concentration of its substrate, ACh with an increase reached up to 42.8%. Spinetoram had also a prominent effect upon carbohydrate metabolism as in glycogen content which was decreased by 34.9%, LDH also was inhibited to 55.7% while trehalase had an elevated activity by 22.8%.In general, Behira Governorate was more affected and more sensitive to spinetoram rather than Kalyobia Governorate. The present work is an introductory study to understand the outline of the mechanism of this bioinsecticide as well as the resistance mechanisms may arise in the future.

Effect of Some Insecticides on Certain Enzymes of Spodoptera Littoralis (Bosid.)

“…The three tested insecticides caused a high significant reduction in both α and βesterase except pyridalyl which caused a significant increase in β-esterase. These results were in harmony with those recorded by Fahmy and Dahi (2009). The same reduction were obtained by Bakr et al, (2010).…”

EFFECT OF FOUR BIOACTIVE COMPOUNDS SEPARATELY AND IN COMBINATION WITH Metarhizium anisopliae ON THE ACTIVITY OF SOME HAEMOLYMPH ENZYMES OF Schistocerca gregaria (FORSKAL).

“…Trehalse could be used as parameter for assessing the availability of nutrients (Ishaaya and Swirkski, 1976) in this study the activity of trehalase after 2 days from inoculation in all treatments except abamectin and mixture from M. anisoplaiae and plant extract from S. molle and in all treatments after 4 days is lower than control, this decrease due to The decreasing in trehalase activity may be due to toxicity stress of the treatments as indicating by many authors (Fahmy and Dahi, 2009, Elbanna et al, 2013and (Rashwan, 2013. Increase in activity of trehalase after 2 days from inoculation in abamectin are in parallel to (Dahi, et al, 2009) which found increase in activity of trehalase when treated Egyptian cotton leaf worm Spodoptera littoralis with avermectin While the activity is increased after 6 days from infection in case Neem, plant extract from S. molle and L-glutamic acid this result are in parallel to (Mohamed, 2014) which treated S. gregaria with Neem and found the activity of trehalase in insect which treated with Neem are higher than control. While in case of insect which treated with abamectin after 6 days the activity of trehalase is lower than control this result are in parallel to (Abo El-Ghar et al 1995) which found that when feeding Spodoptera littoralis larvae 5 ppm abamectin caused remarkable decrease in trehalase activities.…”

Disturbance of the Acetylcholinesterase Activity in Haemolymph and Fat Bodies of The Desert Locust, Schistocerca gregaria (Orthoptera: Acrididae) by Margosan-O® (0.3% Azadirachtin)

“…Similar findings were reported, also, in the 4 th instar larvae of S. littoralis after treatment with camphor plant oil followed by chlorpyrifos (Fetoh and Asiry, 2013). Many authors (El-Barky et al, 2008;Fahmy and Dahi, 2009;Rashwan, 2013) reported a moderate induction of AchE activity of the same insect after treatment with Spinetoram or emamectin and teflubenzuron (Assar et al, 2016). The activity of AchE in the 4 th instar larvae of the red flour beetle Tribolium castaneum was significantly induced by garlic essential oil (Allium sativum) (El-Gizawy et al, 2019).…”