The study of predators and parasites of molluscs has long been of academic interest although early records for slug predation and parasitism are largely restricted to the anecdotal information contained in comprehensive works on slugs and snails, such as Taylor (1902-1907). More recently, the possible use of a range of other organisms in the biological control of pest species of slug has attracted considerable attention and the potential for exploitation of these organisms suggests that they may have an important role in the future control of slugs (Port and Port, 1986). It is difficult to obtain evidence from direct observations in the field but this has been done successfully for birds (e.g. Feare et al., 1974). Slugs have also been offered to a range of potential predators in the laboratory (e.g. Feare et al., 1974; Poivre, 1972; Tod, 1973) although acceptance does not show whether slugs form part of the normal prey of a specific predator. One difficulty in the study of the predation of slugs is the identification of mollusc remains in the gut of a potential predator, particularly in fluid feeders such as many carabid beetles (Davies, 1953). Digestion of the slug is often rapid, particularly in birds, and the only structures which resist digestion are the jaw, radula and, very occasionally, fragments of the internal shell. The jaws of slugs, particularly D. reticulatum, can, however, be identified and the weight of individuals of this species consumed by the predator can be estimated (South, 1980).
KeywordsIntermediate Host Digestive Gland Carabid Beetle Common Shrew Mantle Cavity
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