Comparative toxicity of certain compounds against terrestrial snails <i>Monacha cantiana</i> and <i>Succinea putris</i> (Gastropoda: Hygromiidae: Succineidae) under laboratory and field conditions

Monacha cantiana (Montagu) and Succinea putris (L.) (Gastropoda: Succineidae: Hygromiidae) are among the most significant harmful land snails affecting various economic crops in Kafr El-Sheikh Governorate, Egypt. This study compared the toxicity of different concentrations of certain pesticides against these two snail species using two methods under both laboratory and field conditions. The results indicated that, under laboratory conditions, the poison bait method was more effective than the leaf-dipping method. Among the pesticides tested, indoxacarb proved to be the most effective against M. cantiana when applied using the poison bait and leaf-dipping methods, followed by emamectin benzoate and tolfenpyrad, with LC50 values of (2.70, 8.29, and 87.92 ppm) and (1.62, 12.03, and 95.31 ppm) for the two methods, respectively. For the land snail S. putris, emamectin benzoate showed the highest effect, followed by indoxacarb and tolfenpyrad, the LC50 values were (2.79, 3.23, and 62.69 ppm) and (3.33, 4.19, and 67.14 ppm), for the poison bait and leaf-dipping methods, respectively. Conversely, under field conditions, the toxic baits of indoxacarb, emamectin benzoate, and tolfenpyrad achieved mortality rates of 99.5%, 85.83% and 83.07% for the land snail M. cantiana, respectively, after 21 days of application. Therefore, control programs targeting these land snails can effectively use these compounds, particularly indoxacarb, as molluscicides.