Emamectin benzoate as a potential molluscicide against white garden snail, Theba pisana in association with biochemical defects

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 and highly effective pesticide. This study focused on the lethal and in vivo sublethal toxic effect of EMB on the energy reserves (glycogen, lipids and proteins), total energy reserves and activities of 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 days of exposure. RESULTS The median lethal dose (LD50) at 48 h of EMB treatment was 5.34 μg g−1 body weight (b.w.). Sublethal doses of 1.07 and 3.20 μg g−1 b.w. (i.e., 20% and 60% of the LD50) led to significant dose‐ and time‐dependent decreases in glycogen and lipids; these doses increased the total protein level. Overall, the tested sublethal doses significantly decreased the total energy reserves. Moreover, GST and γ‐GT activities were elevated, whereas the activities of AST and ALT were inhibited in the exposed snails. A decrease in LDH activity after 1 and 3 days of exposure and an increase after 7 days of exposure were seen in snails treated with EMB. CONCLUSION EMB exerted lethal toxicity on T. pisana and consequently caused changes in energy reserve levels and enzyme activities in the animal. © 2022 Society of Chemical Industry. EMB has a lethal effect on Theba pisana, 48‐h LD50 is 5.34 μg g−1 bw. Sublethal doses of EMB (20% and 60% LD50) can negatively impact energy reserves and alter enzymatic activity in snails.