Toxicity and physiological effects of diallyl sulfide and dialyl disulfide on Tuta absoluta Meyrick

Abstract

Toxicity and physiological effects of the two components within garlic essential oil, diallyl sulfide, and diallyl disulfide, were studied against the larvae of Tuta absoluta. The larvae treated by dially sulfide showed the LC50 of 0.518% while it was observed 0.390% in those treated by diallyl disulfide. The LT50 values of diallyl sulfide and diallyl disulfide were calculated 9.65 and 7.18 h, respectively. The binary mixture of the given compounds in the different ratios revealed the higher expected mortality than the observed one implying antagonistic interaction against the larvae of T. absoluta. Diallyl sulfide and diallyl disulfide in both LC30 and LC50 concentrations significantly decreased the activities of larval α-amylase, glucosidases, and lipase. The LC50 concentration of diallyl sulfide caused the lower activity of general protease than LC30 concentration but the least activity of general protease was recorded in the larvae treated by both concentrations of diallyl disulfide. Treatment of T. absoluta larvae by both concentrations of dially sulfide and diallyl disulfide significantly decreased the activities trypsin, chymotrypsin, and elastase as well as amino- and carboxypeptidases compared to control. The larval treatment with two concentrations of diallyl sulfide and diallyl disulfide significantly decreased the activity of acetylcholine esterase compared to control in both in vivo and in vitro assays. Diallyl sulfide and diallyl disulfide significantly decreased the activity of alanine aminotransferase compared to control while the highest activity of aspartate aminotransferase was recorded in the larvae treated by LC50 concentration of diallyl disulfide. Dially sulfide and diallyl disulfide significantly decreased the amounts of triglyceride, glycogen, and protein as storage macromolecules compared to control.