BIOLOGICAL STUDIES OF SOME SOIL MITES IN TWO AGROSYSTEMS IN EGYPT

Abstract

Acari has successfully invaded almost all compartments of the biosphere under very different environmental conditions. It can be found in virtually all habitats, in water, in the soil and on plants as well as a great number of species are ecto- or endoparasites. This remarkable diversity is reflected in numerous morphological and biological specializations. The Acari is not small enough to be handled like protozoans or soft bodied enough to be treated as worms and they are too small to be studied like insects.

Regarding to the systematic position, mites are included into phylum Arthropoda, class Arachnida, and Subclass Acari. The later is characterized by the absence of somatic segmentation, mouthparts contained indiscrete anterior gnathosoma or capitulum that resembles the head of the generalized arthropods. The remaining body is named idiosoma, which is divided into podosoma and opisthosoma.

Mites are a common and widespread arthropod occurring in soil throughout the world. They exist in all soils in land with high species richness, abundance and diversity. Some of soil mites are actively involved in decomposition of organic matter, in nutrient cycling and in soil formation. Some species are predaceous and play an important role as biocontrol agents against harmful soil pests. They are often used as a significant indicator of soil quality and soil health, as they are vulnerable to land use changes.