Mesostigmata is an order of mites belonging to the Parasitiformes. They are by far the largest group of Parasitiformes, with over 8,000 species in 130 families. Mesostigmata includes parasitic as well as free-living and predatory forms. They can be recognized by the single pair of spiracles positioned laterally on the body.
The family with the most described species is Phytoseiidae. Other families of note are Diplogyniidae, Macrochelidae, Pachylaelapidae, Uropodidae and Veigaiidae.
Amongst the best known species are Varroa destructor, an economically important parasite of honey bees, as well as the red mite (Dermanyssus gallinae) a parasite of poultry, most commonly chickens.
The oldest known record of the group is an indeterminate deutonymph belonging to Sejidae from the mid Cretaceous (Albian-Cenomanian) aged Burmese amber of Myanmar.[2]