Molluscicidal effects of saponin-rich plant extracts on the grey field slug

Abstract

D. González-Cruz, and R. San Martín. 2013. Molluscicidal effects of saponin-rich plant extracts on the grey field slug. Cien. Inv. Agr. 40(2): 341-349. Slug control is a major concern in crop fields because these mollusks consume and damage plants that are destined for human consumption and ornamentation. The grey field slug Deroceras reticulatum (Müller, 1774) is one of the most commonly occurring mollusks with agronomic importance, consuming up to 80% of the leaf surface of raps and other crops. The major difficulty in slug control is that the main products used for this purpose can also endanger non-target animals, such as pets and birds. New methods of control that are naturally based and environmental friendly are urgently required, both for the farmer who applies the product and for the final consumer. In this study, we analyzed the anti-molluscal activity of extracts from three plant with a high content of saponins: Camellia oleifera, Gleditsia amorphoides and Quillaja saponaria. Forced oral injection and histological analyses of the digestive system were performed to measure the effects of the plant extracts against slugs. All three extracts showed anti-feeding activity and toxicity against slugs when injected orally at a range of concentrations between 1 and 4% w/w. All three extracts also damaged the gastric epithelium of the crop region of the slugs, suggesting that they show strong membranolytic properties in the digestive system of these mollusks. This study revealed novel natural compounds that can potentially be used in the control of grey field slugs. The data hereby presented could be useful in future comparative studies between other mollusks with agronomic importance.