Molluscicidal effects of Repcar fertilizer and certain chemical compounds on terrestrial snail Monacha obstructa under laboratory and field conditions

Land snails, particularly Monacha obstructa, are destructive pests that infest a wide range of field and vegetable crops. This study aimed to evaluate the effectiveness of certain chemical compounds against the terrestrial snail, M. obstructa under laboratory and field conditions. Three bioassay methods were used in the laboratory: baiting, leaf-dipping, and residual film techniques. The tested chemical compounds included several clethodim, bentazone and bifenazate compared with a fertilizer (Repcar 4% S). The laboratory results indicated that Repcar was the most toxic compound across all techniques, followed by Clethodim while Bifenazate showed the least toxicity. Among the tested bioassay methods, the residual film technique proved to be the most effective, yielding the lowest LC50 value and highest bioactivity. Furthermore, under field conditions, Repcar and Clethodim achieved the highest reduction percentages in snail populations. These findings suggest that integrating chemical compounds with fertilizers may enhance pest control strategies. Further research is recommended to assess the environmental impact and long-term effectiveness of these compounds.