Barriers, repellents and antifeedants for slug and snail control

Laboratory bioassays were carried out to evaluate the efficacy of various products with potential for slug and snail control in horticulture and agriculture. The products tested were cinnamamide, copper ammonium carbonate, garlic, aluminium and copper foil, a mulch, ureaformaldehyde and the proprietary products SnailBan(R) and Tex-R(R) matting. The trials were carried out using the slug Deroceras panormitanum (Lessona and Pollonera, 1882) (D. caruanae) and the snail Oxyloma pfeifferi (Rossmassler, 1835), which are the most abundant slug and snail pest species found damaging hardy ornamental plants in commercial nurseries in the UK. The tested products had irritant, antifeedant, physical barrier, chemical repellent, or molluscicidal effects or showed a combination of more than one effect. Garlic, ureaformaldehyde and cinnamamide were the three best products for controlling molluscs. In 7 day bioassay trials these products had mortality rates between 20% and 95% which was significantly higher than on the untreated compost. In comparison to the untreated compost they also gave significant reductions in damage, between 41% and 100%, depending on species and application technique. Further investigations are needed to evaluate their efficacy under field conditions, the behavioural response of the slugs and snails, the most cost-effective concentrations and the best application techniques, and to understand the mode of action of the products. Some of the products will only be applicable in horticulture due to their cost or the practicalities of their use. However, most of the products also may have potential for use in agriculture as the slug tested, D. panormitanum, is closely related to D. reticulatum, the main slug pest species in agriculture. (C) 2003 Elsevier Ltd. All rights reserved.