This family contains more than 500 species of mites. Many are fungal feeders, others are plant pests, and some are even parasites like the tracheal mite which infests honey bees. The species are small to very small, 0.1 to 0.3 mm long. Economically the most important plant parasite is the broad mite, Polyphagotarsonemus latus.
Taxonomically the family is characterized by a number of morphological features. E.g. The bases of the chelicerae are fused and form a special structure with the subcapitulum or the palps are greatly reduced.
The following genera and individual species of plant pests are currently entered under this family: