Terrestrial Slugs. Biology, Ecology and Control

South's stated objective: 'to present a review of current knowledge of the biology and ecology of slugs, together with their status and control as pests' is achieved by a thorough and scholarly work of a high standard. A summary of slug groups, with particular reference to the British fauna, is followed by detailed reviews of anatomy, physiology, reproduction, behaviour, life cycles and ecology. Additional topics surveyed include predation, parasites and disease, slugs as pests and their control. Appendices cover methods of culture, the anaesthetising, narcotising and preserving of slugs.

The text is interspersed with a diverse array of facts that I found fascinating. In the review of predation, for example, is the case of the garter snake Thamnophis elegans which is polymorphic, having a slug-eating genotype, for which slugs may constitute 90 of the diet, and a slug-refusing morph that would starve to death rather than feed on slugs. In the section on slugs and man the use of slugs to combat ailments ranging from tuberculosis to lumbago and warts are activities of our recent past that I was not aware of, as was the use of Anon ater to lubricate cart wheels. However, I did know of a slug horror story that was set in my own South London suburb of Merton, which I believe was made into a film.

Because slugs represent a diverse array of heterobranch groups, much of the information is relevant to terrestrial gastropods in general. In fact, I have always been puzzled that so many workers should concentrate on such an unnatural group as slugs, independently of shelled gastropods. South does not set out to consider detailed aspects of systematics and taxonomy beyond the British fauna. There are few references to monographic and faunistic studies, particularly of tropical groups, and there is little discussion of relationships. For example, while stating that athoracophorids are unlike any other slugs, there is no discussion of their similarities with the anomalous succineid snails which may yet prove to be opisthobranchs. I found the discussions of the evolution of slug form and diversity of slug families disappointing because of their brevity.

Whilst recognizing that the bias is toward European species, South points out that most published information is on European species and that several of these now have a cosmopolitan distribution. Those wishing to use slugs in teaching or research, or who are concerned with slugs as pests, are particularly well-catered for. However, there is no doubt that South has succeeded in providing a source of reference and extensive bibliography that will provide indispensable to any slug worker regardless of their specialization or geographical province.