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.

Taxonomy to families (Beaulieu 2011). Genus and species counts fluctuate over time. - Order Mesostigmata G. Canestrini, 1891 - Suborder Monogynaspida Camin & Gorirossi, 1955 - Infraorder Gamasina Kramer, 1881 - Hyporder Arctacariae Johnston, 1982 - Superfamily Arctacaroidea Evans, 1955 - Family Arctacaridae Evans, 1955 (2 genera, 6 species) - Hyporder Dermanyssiae Evans & Till, 1979 - Superfamily Ascoidea Voigts & Oudemans, 1905 - Family Ameroseiidae Evans, 1961 (10 genera, 148 species) - Family Ascidae Voigts & Oudemans, 1905 (17 genera, 338 species) - Family Melicharidae Hirschmann, 1962 (12 genera, 201 species) - Superfamily Dermanyssoidea Kolenati, 1859 - Family Dasyponyssidae Fonseca, 1940 (2 genera, 2 species) - Family Dermanyssidae Kolenati, 1859 (2 genera, 26 species) - Family Entonyssidae Ewing, 1923 (9 genera, 27 species) - Family Haemogamasidae Oudemans, 1926 (5 genera, 78 species) - Family Halarachnidae Oudemans, 1906 (7 genera, 43 species) - Family Hystrichonyssidae Keegan, Yunker & Baker, 1960 (1 genus, 1 species) - Family Iphiopsididae Kramer, 1886 (14 genera, 68 species) - Family Ixodorhynchidae Ewing, 1923 (6 genera, 43 species) - Family Laelapidae Berlese, 1892 (90 genera, 1316 species) - Family Larvamimidae Elzinga, 1993 (6 genera, 43 species) - Family Macronyssidae Oudemans, 1936 (34 genera, 233 species) - Family Manitherionyssidae Radovsky & Yunker, 1971 (1 genus, 1 species) - Family Omentolaelapidae Fain, 1961 (1 genus, 1 species) - Family Rhinonyssidae Trouessart, 1895 (8 genera, 510 species) - Family Spelaeorhynchidae Oudemans, 1902 (1 genus, 7 species) - Family Spinturnicidae Oudemans, 1901 (12 genera, 101 species) - Family Varroidae Delfinado & Baker, 1974 (2 genera, 6 species) - Superfamily Eviphidoidea Berlese, 1913 - Family Eviphididae Berlese, 1913 (19 genera, 108 species) - Family Leptolaelapidae Karg, 1978 (12 genera, 48 species) - Family Macrochelidae Vitzthum, 1930 (20 genera, 470 species) - Family Pachylaelapidae Berlese, 1913 (26 genera, 199 species) - Family Parholaspididae Evans, 1956 (12 genera, 96 species) - Superfamily Phytoseioidea Berlese, 1916 - Family Blattisociidae Garman, 1948 (11 genera, 369 species) - Family Otopheidomenidae Treat, 1955 (10 genera, 28 species) - Family Phytoseiidae Berlese, 1916 (90 genera, 2300 species) - Family Podocinidae Berlese, 1913 (2 genera, 25 species) - Superfamily Rhodacaroidea Oudemans, 1902 - Family Digamasellidae Evans, 1957 (13 genera, 261 species) - Family Halolaelapidae Karg, 1965 (4 genera, 80 species) - Family Laelaptonyssidae Womersley, 1956 (1 genus, 6 species) - Family Ologamasidae Ryke, 1962 (45 genera, 452 species) - Family Rhodacaridae Oudemans, 1902 (15 genera, 148 species) - Family Teranyssidae Halliday, 2006 (15 genera, 148 species) - Superfamily Veigaioidea Oudemans, 1939 - Family Veigaiidae Oudemans, 1939 (4 genera, 95 species) - Hyporder Epicriiae Kramer, 1885 - Superfamily Epicrioidea Berlese, 1885 - Family Epicriidae Berlese, 1885 (4 genera, 48 species) - Superfamily Heatherelloidea Walter, 1997 - Family Heatherellidae Walter, 1997 (1 genus, 2 species) - Superfamily Zerconoidea G. Canestrini, 1891 - Family Coprozerconidae Moraza & Lindquist, 1999 (1 genus, 1 species) - Family Zerconidae G. Canestrini, 1891 (36 genera, 390, species) - Hyporder Parasitiae Evans & Till, 1979 - Superfamily Parasitoidea Oudemans, 1901 - Family Parasitidae Oudemans, 1901 (35 genera, 426 species) - Infraorder Uropodina Kramer, 1881 - Family Dithinozerconidae Ainscough, 1979 - Superfamily Diarthrophalloidea Trägårdh, 1946 - Family Diarthrophallidae Trägårdh, 1946 (22 genera, 63 species) - Superfamily Microgynioidea Trägårdh, 1942 - Family Microgyniidae Trägårdh, 1942 (2 genera, 4 species) - Family Nothogynidae Walter & Krantz, 1999 (1 genus, 2 species) - Superfamily Thinozerconoidea Halbert, 1915 - Family Protodinychidae Evans, 1957 (1 genus, 3 species) - Family Thinozerconidae Halbert, 1915 (1 genus, 1 species) - Superfamily Uropodoidea Kramer, 1881 - Family Baloghjkaszabiidae Hirschmann, 1979 (1 genus, 3 species) - Family Brasiluropodidae Hirschmann, 1979 (2 genera, 18 species) - Family Cillibidae Trägårdh, 1944 (2 genera, 19 species) - Family Clausiadinychidae Hirschmann, 1979 (1 genus, 4 species) - Family Cyllibulidae Hirschmann, 1979 (1 genus, 32 species) - Family Deraiophoridae Trägårdh, 1952 (1 genus, 36 species) - Family Dinychidae Berlese, 1916 (1 genus, 34 species) - Family Discourellidae Baker & Wharton, 1952 (1 genus, 76 species) - Family Eutrachytidae Trägårdh, 1944 (1 genus, 36 species) - Family Hutufeideriidae Hirschmann, 1979 (1 genus, 9 species) - Family Kaszabjbaloghiidae Hirschmann, 1979 (1 genus, 6 species) - Family Macrodinychidae Hirschmann, 1979 (4 genera, 22 species) - Family Metagynuridae Balogh, 1943 (2 genera, 17 species) - Family Nenteriidae Hirschmann, 1979 (2 genera, 128 species) - Family Oplitidae Johnston, 1968 (8 genera, 163 species) - Family Phymatodiscidae Hirschmann, 1979 (1 genus, 10 species) - Family Polyaspididae Berlese, 1913 (1 genus, 16 species) - Family Prodinychidae Berlese, 1917 (3 genera, 16 species) - Family Rotundabaloghiidae Hirschmann, 1979 (4 genera, 165 species) - Family Tetrasejaspidae Hirschmann, 1979 (1 genus, 15 species) - Family Trachytidae Trägårdh, 1938 (7 genera, 108 species) - Family Trachyuropodidae Berlese, 1917 (17 genera, 99 species) - Family Trematuridae Berlese, 1917 (13 genera, 401 species) - Family Trichocyllibidae Hirschmann, 1979 (5 genera, 57 species) - Family Trichouropodellidae Hirschmann, 1979 (1 genus, 11 species) - Family Trigonuropodidae Hirschmann, 1979 (1 genus, 87 species) - Family Uroactiniidae Hirschmann & Zirngiebl-Nicol, 1964 (3 genera, 67 species) - Family Urodiaspididae Trägårdh, 1944 (3 genera, 26 species) - Family Urodinychidae Berlese, 1917 (13 genera, 267 species) - Family Uropodidae Kramer, 1881 (9 genera, 261 species) - Suborder Sejida Kramer, 1885 - Superfamily Heterozerconoidea Berlese, 1892 - Family Discozerconidae Berlese, 1910 (2 genera, 3 species) - Family Heterozerconidae Berlese, 1892 (7 genera, 13 species) - Superfamily Sejoidea Berlese, 1885 - Family Ichthyostomatogasteridae Sellnick, 1953 (3 genera, 10 species) - Family Sejidae Berlese, 1885 (5 genera, 46 species) (5 genera, 46 species) - Family Uropodellidae Camin, 1955 (1 genus, 6 species) - Suborder Trigynaspida Camin & Gorirossi, 1955 - Infraorder Antennophorina Camin & Gorirossi, 1955 - Superfamily Aenictequoidea Kethley, 1977 - Family Aenictequidae Kethley, 1977 (1 genus, 1 species) - Family Euphysalozerconidae Kim, 2008 (1 genus, 1 species) - Family Messoracaridae Kethley, 1977 (2 genera, 3 species) - Family Ptochacaridae Kethley, 1977 (1 genus, 3 species) - Superfamily Antennophoroidea Berlese, 1892 - Family Antennophoridae Berlese, 1892 (6 genera, 19 species) - Superfamily Celaenopsoidea Berlese, 1892 - Family Celaenopsidae Berlese, 1892 (7 genera, 14 species) - Family Costacaridae Hunter, 1993 (1 genus, 1 species) - Family Diplogyniidae Trägårdh, 1941 (42 genera, 85 species) - Family Euzerconidae Trägårdh, 1938 (12 genera, 24 species) - Family Megacelaenopsidae Funk, 1975 (2 genera, 2 species) - Family Neotenogyniidae Kethley, 1974 (1 genus, 1 species) - Family Schizogyniidae Trägårdh, 1950 (6 genera, 10 species) - Family Triplogyniidae Funk, 1977 (2 genera, 11 species) - Superfamily Fedrizzioidea Trägårdh, 1937 - Family Fedrizziidae Trägårdh, 1937 (3 genera, 34 species) - Family Klinckowstroemiidae Camin & Gorirossi, 1955 (4 genera, 36 species) - Superfamily Megisthanoidea Berlese, 1914 - Family Hoplomegistidae Camin & Gorirossi, 1955 (1 genus, 7 species) - Family Megisthanidae Berlese, 1914 (1 genus, 30 species) - Superfamily Paramegistoidea Trägårdh, 1946 - Family Paramegistidae Trägårdh, 1946 (5 genera, 30 species) - Superfamily Parantennuloidea Willmann, 1941 - Family Parantennulidae Willmann, 1941 (3 genera, 5 species) - Family Philodanidae Kethley, 1977 (2 genera, 2 species) - Family Promegistidae Kethley, 1977 (1 genus, 1 species) - Infraorder Cercomegistina Camin & Gorirossi, 1955 - Superfamily Cercomegistoidea Trägårdh, 1937 - Family Asternoseiidae Vale, 1954 (2 genera, 3 species) - Family Cercomegistidae Trägårdh, 1937 (5 genera, 13 species) - Family Davacaridae Kethley, 1977 (2 genera, 4 species) - Family Pyrosejidae Lindquist & Moraza, 1993 (2 genera, 3 species) - Family Saltiseiidae Walter, 2000 (1 genus, 1 species) - Family Seiodidae Kethley, 1977 (1 genus, 1 species) - Other - Meliponopus palpifer Fain & Flechtmann, 1985 has not yet been placed into a family.