Although the ancestral home of chelicerates was the sea, the vast majority of modern species live on land. Most students of spiders and mites also restrict themselves to terrestrial habitats. However, a surprising number of mites (Arachnida: Acari) have returned to a watery existence. Approximately 7000 species from the Mesostigmata, Astigmata, Oribatida, and especially the Prostigmata, now live in marine and freshwater habitats. In Aquatic Mites, a dozen chapters explore the distribution, ecology, behavior, genetics, and evolution of the most diverse of these astonishing arachnids. The results of these studies raise as many interesting questions as they answer, and should provoke more investigations of the biology of freshwater and marine Acari.

Surprising though it seems, the world faces almost as great a threat today from arthropod-borne diseases as it did in the heady days of the 1950s when global eradication of such diseases by eliminating their vectors with synthetic insecticides, particularly DDT, seemed a real possibility. Malaria, for example, still causes tremendous morbidity and mortality throughout the world, especially in Africa. Knowledge of the biology of insect and arachnid disease vectors is arguably more important now than it has ever been. Biological research directed at the development of better methods of control becomes even more important in the light of the partial failure of many control schemes that are based on insecticide- although not all is gloom, since basic biological studies have contributed enormously to the outstanding success of international control programmes such as the vast Onchocerciasis Control Programme in West Africa. It is a sine qua non for proper understanding of the epidemiology and successful vector control of any human disease transmitted by an arthropod that all concerned with the problem - medical entomologist, parasitologist, field technician - have a good basic understanding of the arthropod's biology. Knowledge will be needed not only of its direct relationship to any parasite or pathogen that it transmits but also of its structure, its life history and its behaviour - in short, its natural history. Above all, it will be necessary to be sure that it is correctly identified.

More than 40,000 species of mites have been described, and up to 1 million may exist on earth. These tiny arachnids play many ecological roles including acting as vectors of disease, vital players in soil formation, and important agents of biological control. But despite the grand diversity of mites, even trained biologists are often unaware of their significance. Mites: Ecology, Evolution and Behaviour (2nd edition) aims to fill the gaps in our understanding of these intriguing creatures. It surveys life cycles, feeding behaviour, reproductive biology and host-associations of mites without requiring prior knowledge of their morphology or taxonomy. Topics covered include evolution of mites and other arachnids, mites in soil and water, mites on plants and animals, sperm transfer and reproduction, mites and human disease, and mites as models for ecological and evolutionary theories.