Spiromesifen, an insecticide inhibitor of lipid synthesis, affects the amounts of carbohydrates, glycogen and the activity of lactate dehydrogenase in Drosophila melanogaster

Abstract

Spiromesifen (Oberon® 240rnSC), an insecticide/acaricide widely used to control pests like mites andrnwhiteflies, was applied topically at two sublethal concentrations (LC10:rn21.45 μg/μl and LC25:rn39.53 μg/μl), on newly molted pupaernof Drosophila melanogaster Meigen, 1830 (Diptera, Drosophilidae). Therneffects of treatment were evaluated on the duration of pupal stage, changes inrnthe pupal weight, the amounts of carbohydrates and glycogen and the rate of thernlactate dehydrogenase. Results show that spiromesifen reduces the amounts ofrnboth total carbohydrates and glycogen in pupae of D. melanogaster asrncompared to controls. Moreover, treatment also caused a significant increase in thernlactate dehydrogenase activity. The biochemical measurements of carbohydrates and glycogen confirm thatrnD. melanogaster exhibit a U-shaped metabolic curve and spiromesifenrntreatment disturbs the energy metabolism and induces a chemical stressrnresulting in an increase in LDH activity.