10th International Scientific Conference on Agricultural Development and Sustainability

16th Symposium of Plant Protection

Biological activity against gastropod pests of Asparagaceae extracts

Abstract

Terrestrial gastropods (Mollusca: Gastropoda) cause economic damage to many crops, including vegetables, legumes, cereals, and fruits. On the other hand, strategies for controlling gastropods are mainly based on chemical molluscicides having metaldehyde or iron phosphate. However, the need for alternative, effective and environmentally benign control measures has become essential. This essentiality is mainly due to concerns about the environmental impact of metaldehyde added to the limited availability of other chemicals. On this background, this research aimed to evaluate the molluscicide activity of extracts of three species of Asparagaceae: Agave brittoniana, Furcraea antillana, and A. furcroydes, against two critical species of pest gastropods: Praticolella griseola and Subulina octona. All the species showed molluscicide activity against P. griseola and S. octona. Its power was similar to or higher than metaldehyde in laboratory tests. In other experiments, the extracts were more than 80% effective in controlling P. griseola and S. octona in the field. Hydrolyzed products of the same compounds showed a significantly lower activity. Hence, the bioactive effect is probably related to saponins in the saps. Likewise, the effectiveness of a residual product from the henequen industry was tested. As a result, an LC 50 similar to that estimated for A. brittoniana was found for the residual against P. griseola. The outcomes were promising for the control of gastropods in agricultural conditions.

Resumen

Los gasterópodos terrestres (Mollusca: Gastropoda) causan daños económicos a una amplia gama de cultivos, incluidas hortalizas, legumbres, cereales y frutas. Las estrategias para su control se basan principalmente en molusquicidas químicos, que contienen metaldehído o fosfato de hierro. Sin embargo, medidas de control alternativas, efectivas y ambientalmente benignas se han vuelto esenciales. El presente trabajo tuvo el objetivo de evaluar la actividad molusquicida de extractos de tres especies de Asparagaceae: Agave brittoniana, Furcraea antillana y A. furcroydes contra dos importantes especies de gasterópodos plaga: Praticolella griseola y Subulina octona. Las especies A. brittoniana, A. fourcroydes y F. antillana presentan actividad molusquicida contra las especies P. griseola y S. octona. Su potencia fue similar o superior a la del metaldehído en ensayos de laboratorio. Adicionalmente, los extractos resultaron tener una eficacia por encima del 80 % para controlar a P. griseola y S. octona en campo. Un producto hidrolizado de los mismos extractos mostró una actividad significativamente menor, lo que induce a concluir que el efecto molusquicida de las savias está asociado a la actividad de las saponinas que las constituyen. Adicionalmente se probó la eficacia de un producto residual de la industria henequenera y se encontró una CL 50 contra P. griseola similar a la estimada para A. brittoniana. Los resultados obtenidos resultaron promisorios para el control de gasterópodos en condiciones agrícolas.