Slugs as Pasture Pests

Several invasive European slug species are thriving in New Zealand and have become important pests of many crops. In pasture, they are particularly damaging to white clover during renovation and the problem may be exacerbated by direct drilling. Slug feeding causes both lethal and sublethal damage that reduces clover establishment and thus pasture quality. Much less is known about slug damage to established pastures and the degree to which slugs limit pasture persistence. Established pastures frequently support large slug populations that feed on clover and the application of molluscicides can reduce slug numbers and increase the proportion and yields of clover. Future research on these pests should concentrate on determining damage thresholds, breeding resistant clover varieties and developing agronomic practices that favour natural enemies. In the long term, there is much potential for developing microbiological pesticides that target slugs. Keywords: molluscs, slugs, clover