Assessment of molluscicidal activity of Syzygium aromaticum essential oil against Eobania vermiculata under laboratory and field conditions.

Abstract

The present study focused on assessing the impact of clove oil on adult snails, specifically Eobania vermiculata, due to their detrimental effects on plants and crops. Our investigation aimed to explore both the lethal and sub-lethal toxicity of clove oil under laboratory and field conditions, with the goal of elucidating the mechanisms underlying its toxic effects on E. vermiculata. Snails were exposed to various concentrations of clove oil for one week to determine the LC₅₀, which was calculated to be 5.25% v/v (4.029-6.087). To investigate the molluscicidal effects of clove oil, snails were divided into three groups: control, vehicle-treated (1 % Tween 80), and treated group exposed to sub-lethal concentration (½ LC₅₀) of clove oil for one week. Compared to the control group, the exposure to ½ LC₅₀ of clove oil for 7 days resulted in significant increases in alkaline phosphatase (ALP), malondialdehyde (MDA), catalase (CAT), and superoxide dismutase (SOD). Conversely, the level of acetylecholnstrase (AChE) and glutathione peroxidase (GPx) was decreased. Furthermore, testosterone (T) and estrogen (E) levels were significantly reduced. Histological and ultrastructural studies revealed significant tissue disorganization. Additionally, Comet assay results confirmed the genotoxic potential of clove oil on E. vermiculata. Field trials demonstrated a higher reduction in snail populations in plots treated with methomyl (80% and 92% reduction after 7 and 14 days, respectively) compared to those treated with clove oil (64% and 73% reduction, respectively). While slightly less effective than methomyl, clove oil offers a valuable, natural, and residue-free alternative for eco-friendly snail management.