LAUSR

BACKGROUND The white garden snail, Theba pisana is distributed worldwide and is a serious molluscan pest of different crops. Emamectin benzoate (EMB) "an avermectin derivative" is a novel biorational agent that is highly effective pesticide. This study focused on its lethal and in vivo sub-lethal toxic effect on the energy reserves (glycogen, lipids and proteins), the total energy reserves and the enzyme activities; Glutathione-S-transferase (GST), γ-Glutamyl transferase (γ-GT), Lactate dehydrogenase (LDH), Aspartate aminotransferase (AST) and Alanine aminotransferase (ALT) in the hepatopancreas of T. pisana for up to 7 d of exposure. RESULTS The median lethal dose (LD50 ) value at 48 h of EMB treatment was 5.34 μg g-1 body weight (b.w). Its sub-lethal doses; 1.07 and 3.20 μg g-1 b.w (20 and 60% LD50 ) led to significant decreases in dose- and time- dependent for glycogen and lipids, while these doses increased the level of total proteins. Overall, the tested sub-lethal doses significantly decreased the total energy reserves. Moreover, it elevated the GST and γ-GT activities, whereas inhibited the activities of AST and ALT in the exposed snails. A decrease of LDH activity after 1 and 3 d and an increase in its activity were observed in treated snails after 7 d of exposure. CONCLUSION EMB exerted lethal toxicity to T. pisana and consequently caused changes in energy reserve levels and enzyme activities in the animal.