ABSTRACT
MICHAEL W EBER Institute of Zoology, Johannes Gutenberg University, Mainz, Germany
Many carabids and staphylinids as well as a great part of the known species of spiders live on the soil surface or in soil crevices, invade the natural pore system of soils, or are in some way closely associated with the soil system. Many carabid and staphylinid larvae actively burrow through the soil. These groups thus form an integral part of the soil macrofauna. Carabids, staphylinids, and spiders are treated here together in a separate chapter because they have in common that they are mostly polyphagous predators, and that they can significantly affect the population dynamics of many phytophagous and saprophagous invertebrates. In natural ecosystems spiders constitute the main invertebrate predatory group together with the carabids and staphylinids by the number of individuals and in some habitats also by the number of species. An economically important eco logical function is their contribution to pest control.
