Biology and Ecology of Agriolimax reticulatus (Mull.) and Other Slugs: Spatial Distribution

Abstract

A study of spatial distribution in a population of slugs on farmland in Northumberland showed that slugs and egg batches were strongly aggregated on grassland. Agriolimax reticulatus was aggregated with respect to areas of about 19 cm2 and areas of about 929 cm2 but not with respect to intermediate areas. Arion fasciatus (Nilss.) was more dependent on soil moisture than the other species examined. A. reticulatus appears to exhibit homing behavior. The distribution of Arion intermedius Norm, was also examined. It was suggested that adequate shelter determined the distribution of slugs in the study area. It is possible that the aggregated distribution of A. reticulatus was brought about by egg-laying behavior and differential egg mortality and persisted because of the poor dispersive powers of this species.