Mesostigmata

t

Taxonomy

updated 2025

Diagnostic characters

Female schizodorsal or divided dorsal shield with setae of dorsal hexagon (j5, z5, j6) dissimilar in form; opisthogastric shield with fewer than 18 pairs of setae, genital region Λ-shaped, with a single anterior point; setae al1, al2 on palp genu in deutonymphs and adults spatulate; corniculi short, not extending to anterior margin of palp femur; tritosternum of male absent or rudimentary; deutonymph (and sometimes female) with spurs on leg II femur (on tubercles), genu, and usually tibia and tarsus.

Diagnostic characters of deutonymphs

• Dorsal shield divided
• Seta z5 simple or stout and distally pilose
• Spurs on leg II femur (on tubercles), genu, and usually tibia and tarsus

Key to some Gamasodes deutonymphs

1. Tibia II with 1 ventral spur; > 2 pairs of dorsal setae stout and distally pilose............. 2
   -  Tibia II with 2 ventral spurs; only dorsal setae j1 and r3 stout and distally pilose............. G. bispinosus (Halbert)

2. With more than one spur on femur II ............. Gamasodes spp.
   -   With a spine spur on the venter of femur II............. 3

3. Spur on femur II straight; tectum with median process and weakly lateral teeth............. G. fimbriatus Karg
   -  Spur on femur II curved; tectum clearly tripartite............. G. spiniger (Trägårdh)

Similar taxa

Key to some Parasitine genera (adult females) (modified from Hyatt 1980)

1. Lateral setae of palp genu (al1–2) entire, either setiform or spatulate.............................. 2
   - Lateral setae of palp genu (al1–2) bifid.............................. Eugamasus

2. Posterior ventral region (opisthogaster) with 30 or fewer pairs of setae; associated with a variety of insects, but usually not bumblebees (Bombus).............................. 3
   - Opisthogaster with extensive hypertrichy (>40 pairs of setae); associated with bumblebees (Bombus) or their nests.............................. Parasitellus

3. Corniculi of normal length, not reaching the anterior margin of the palp femur; anterior margin of anterior dorsal shield convex.............................. 4
   - Corniculi elongate, extending beyond palp femur-genu articulation; margin of anterior dorsal shield concave.............................. Cornigamasus

4. Genital shield (or genital region of hologastric shield) subtriangular, acuminate.............................. 5
   - Genital region of hologastric shield distally tricuspid.............................. Porrhostaspis

5. Lateral seta of palp femur (al) entire, usually spatulate.............................. 8
   - Lateral seta of palp femur bifid, serrate, or serrate-spatulate.............................. 6

6. Setae of dorsal hexagon dissimilar, seta z5 longer and usually thicker than j5 and j6............................... 7
   - Setae of dorsal hexagon similar in size and ornamentation.............................. Vulgarogamasus

7. Sternal shield entire; seta z5 usually thicker than j5 and j6 and distally pilose associated with dung (and dung beetles), compost, etc.............................. Parasitus
   - Sternal shield split medially; seta z5 usually longer than j5 and j6 but similar in form; associated with bark beetles.............................. Schizosthetus

8. Dorsal shield completely divided.............................. 9
   - Schizodorsal shield.............................. Gamasodes bispinosus group

9. Seta z5 of dorsal hexagon thickened and distally pilose; associated with various insects.............................. 10
   - Seta z5 simple; associated with carrion beetles (Silphidae).............................. Poecilochirus

10. Articulation between sternal and metasternal shields oblique; ambulacra of legs II–IV simple, rounded.............................. Gamasodes
    - Articulation (or suture) between sternal and metasternal shields transverse; ambulacra of legs II–IV long and acuminate.............................. Trachygamasus

Ecology and distribution

Soil-inhabiting predators of small arthropods and other invertebrates; several species have been found in the nests of birds and mammals and one species in rotting fungal sporocarps; phoretic on muscid and drosophilid flies (rarely on dung beetles).

Known species

ca. 25 described species: Gamasodes aequipilis Athias-Henriot, 1980 (Iceland), Gamasodes assamensis Bhattacharyya, 1971Bhattacharyya, 1971:
Bhattacharyya SK. 1971. Studies on Indian mites (Acarina: Mesostigmata): 10. One new species and five records from Assam. Oriental Insects 5: 495–500. (India), Gamasodes bispinosus (Halbert, 1915Halbert, 1915:
Halbert JN. 1915. Claire Island Survey. Acarinida Section II - Terrestrial and marine Acarina. Proceedings of the Royal Irish Academy 31 (39): 45–136.) (Europe, USSR), Gamasodes buettikeri Samšiňák, 1979Samšiňák, 1979:
Samšiňák K. 1979. Mites of Saudi Arabia Acari from Musca domestica. Fauna Saudi Arabia 1: 69–74. (Saudi Arabia), Gamasodes bulgatus Athias-Henriot, 1979Athias-Henriot, 1979:
Athias-Henriot C. 1979. Sur le groupe d’espèces “bispinosus” du genre Gamasodes Oudemans, 1939 (Parasitiformes, Parasitidae). Bulletin Société Zoologique du France 104: 209–220. (Canary Islands), Gamasodes coprophilus Chelebiev, 1980Chelebiev, 1980:
Chelebiev KA. 1980. On mites of the genus Gamasodes (Parasitiformes, Parasitidae) from central Kazakhstan. Zoologicheskii Zhurnal 59: 1098–1100. (USSR), Gamasodes corniculans Athias-Henriot, 1978Athias-Henriot, 1978:
Athias-Henriot C. 1978. Deutonymphen der Gattung Gamasodes Oudms (Parasitiformes, Parasitidae) aus der Mongolei. Annales Historico-Naturales Musei Nationalis Hungarici 70: 345–348. (Mongolia), Gamasodes diceras Athias-Henriot, 1980 (Europe), Gamasodes fimbriatus Karg, 1971Karg, 1971:
Karg W. 1971. Acari (Acarina), Milben Unterordnung Anactinochaeta (Parasitiformes) Die freilebenden Gamasina (Gamasides), Raubmilben. Die Tierwelt Deutschlands 59: 1–475. (Europe), Gamasodes guoluoensis Gu and Liu, 1995Gu and Liu, 1995:
Gu Y-M, Liu J-O. 1995. A new species of the genus Gamasodes from China (Acari: Parasitidae). Acta Zootaxonomica Sinica 20: 65–67. (China), Gamasodes hortivagus (Berlese, 1903Berlese, 1903:
Berlese A. 1903. Acari nuovi Manipulus I us. Redia 1: 235–252.) (Europe, Algeria, Canary Islands [= Gamasodes cabylus Athias-Henriot 1961], Gamasodes ignoratus Oudemans, 1939bOudemans, 1939b:
Oudemans AC. 1939b. Neue funde auf dem gebiete der systematik und der nomenklatur der Acari IV. Zoologischer Anzeiger 126: 195–201. (Europe), Gamasodes inermis Athias-Henriot, 1978Athias-Henriot, 1978:
Athias-Henriot C. 1978. Deutonymphen der Gattung Gamasodes Oudms (Parasitiformes, Parasitidae) aus der Mongolei. Annales Historico-Naturales Musei Nationalis Hungarici 70: 345–348. (Mongolia), Gamasodes marmotae Ma, 1992Ma, 1992:
Ma LM. 1992. Descriptions of a new species and an unknown male of Gamasodes from north Qing-Zang Plateau (Acari: Mesostigmata, Parasitidae). Acta Entomologica Sinica 35: 113–116. (China), Gamasodes micherdzinskii Davydova, 1973Davydova, 1973:
Davydova MS. 1973. Description of new species from the genus Gamasodes and the male of Veigaia beklemischevi (Parasitiformes, Gamasoidea). pp. 103–112. In: Cherepanov AI, ed. New and little-known species of siberian fauna, Vol. 6. Nauka, Novosibirsk. (USSR, China), Gamasodes miliaris Athias-Henriot, 1980 (Morocco), Gamasodes nudus Tseng, 1995Tseng, 1995:
Tseng YH. 1995. A taxonomical study of free-living gamasine mite family Parasitidae Oudemans (Acari, Mesostigmata) from Taiwan. Journal of the Taiwan Museum 48: 11–81. (Taiwan), Gamasodes plenigranosus Athias-Henriot, 1979Athias-Henriot, 1979:
Athias-Henriot C. 1979. Sur le groupe d’espèces “bispinosus” du genre Gamasodes Oudemans, 1939 (Parasitiformes, Parasitidae). Bulletin Société Zoologique du France 104: 209–220. (Madagascar), Gamasodes poppei (Oudemans, 1903Oudemans, 1903:
Oudemans AC. 1903. Acarologische Aanteekeningen. VI. Entomologische Berichten 1 (12): 83–88.) (Europe), Gamasodes queenslandicus Halliday and Walter, sp. nov., Gamasodes simplex Athias-Henriot, 1978Athias-Henriot, 1978:
Athias-Henriot C. 1978. Deutonymphen der Gattung Gamasodes Oudms (Parasitiformes, Parasitidae) aus der Mongolei. Annales Historico-Naturales Musei Nationalis Hungarici 70: 345–348. (Mongolia), Gamasodes sinicus Tian and Gu, 1991Tian and Gu, 1991:
Tian QY, Gu YM. 1991. The first record of Gamasodes in China with description of a new species (Acari: Parasitidae). Acta Zootaxonomica Sinica 16: 432–435. (China), Gamasodes spiniger (Trägårdh 1910Trägårdh 1910:
Trägårdh I. 1910. Acariden aus dem Sarekgebirge. Naturwissenschaftlichen Naturwissenschaftliche Untersuchungen des Sarakgebirges in Schwedisch-Lappland geleitet von Dr Axel Hamberg. Zoology, Stockholm 4 (Lief 4): 375–586.) (Europe) type species [ = Gamasoides spiniger Oudemans 1936Oudemans 1936:
Oudemans AC. 1936. Kritisch historisch overzicht der acarologie, Deerde Gedeelte, 1805-1850. Band A (E J Brill, Leiden): 1–430. (nom nov pro Gamasus spinipes (Koch 1844), Gamasodes berlesei Oudemans 1939bOudemans 1939b:
Oudemans AC. 1939b. Neue funde auf dem gebiete der systematik und der nomenklatur der Acari IV. Zoologischer Anzeiger 126: 195–201.. nom nov pro Gamasus spinipes (Koch 1844), Parasitus lunarisimilis Schweizer, 1961], Gamasodes tongdensis Li et al., 1999Li et al., 1999:
Li C, Yang XZ, Chen HJ. 1999. A new species of the genus Gamasodes from China (Acari: Parasitidae). Acta Zootaxonomica Sinica 24: 156–158. (China), Gamasodes viretianus Athias-Henriot, 1980 (Europe)

References

• Athias-Henriot 1961bAthias-Henriot 1961b:
  Athias-Henriot C. 1961b. Physallolaelaps ampulliger Berl et Gamasodes cabylus n. sp. (Parasitiformes: Laelaptidae, Parasitidae). Acarologia 3: 256–264.
• Athias-Henriot 1978Athias-Henriot 1978:
  Athias-Henriot C. 1978. Deutonymphen der Gattung Gamasodes Oudms (Parasitiformes, Parasitidae) aus der Mongolei. Annales Historico-Naturales Musei Nationalis Hungarici 70: 345–348.
• Athias-Henriot 1979Athias-Henriot 1979:
  Athias-Henriot C. 1979. Sur le groupe d’espèces “bispinosus” du genre Gamasodes Oudemans, 1939 (Parasitiformes, Parasitidae). Bulletin Société Zoologique du France 104: 209–220.
• Athias-Henriot 1980bAthias-Henriot 1980b:
  Athias-Henriot C. 1980b. Recapitulatory note on composition and geography of the genus Gamasodes Ouds (Parasitiformes, Parasitidae), with a description of four new species. Biologisch Jaarboek 48: 50–62.
• Berlese 1903Berlese 1903:
  Berlese A. 1903. Acari nuovi Manipulus I us. Redia 1: 235–252.
• Bhattacharyya 1971Bhattacharyya 1971:
  Bhattacharyya SK. 1971. Studies on Indian mites (Acarina: Mesostigmata): 10. One new species and five records from Assam. Oriental Insects 5: 495–500.
• Chelebiev 1980Chelebiev 1980:
  Chelebiev KA. 1980. On mites of the genus Gamasodes (Parasitiformes, Parasitidae) from central Kazakhstan. Zoologicheskii Zhurnal 59: 1098–1100.
• Davydova 1973Davydova 1973:
  Davydova MS. 1973. Description of new species from the genus Gamasodes and the male of Veigaia beklemischevi (Parasitiformes, Gamasoidea). pp. 103–112. In: Cherepanov AI, ed. New and little-known species of siberian fauna, Vol. 6. Nauka, Novosibirsk.
• Fenda 1999Fenda 1999:
  Fenda P. 1999. First records of mites (Acarina, Mesostigmata) from Slovakia. Biologia 54 (5): 528.
• Gu and Liu 1995Gu and Liu 1995:
  Gu Y-M, Liu J-O. 1995. A new species of the genus Gamasodes from China (Acari: Parasitidae). Acta Zootaxonomica Sinica 20: 65–67.
• Halbert 1915Halbert 1915:
  Halbert JN. 1915. Claire Island Survey. Acarinida Section II - Terrestrial and marine Acarina. Proceedings of the Royal Irish Academy 31 (39): 45–136.
• Holzmann 1969Holzmann 1969:
  Holzmann C. 1969. Die Familie Parasitidae Oudemans 1901. Acarologie, Schriftenreihe für Vergleichende Milbenkunde 13: 2–55 + 23 plates.
• Hyatt 1980Hyatt 1980:
  Hyatt KH. 1980. Mites of the subfamily Parasitinae (Mesostigmata: Parasitidae) in the British Isles. Bulletin of the British Museum (Natural History) Zoology 38: 237–378.
• Karg 1971Karg 1971:
  Karg W. 1971. Acari (Acarina), Milben Unterordnung Anactinochaeta (Parasitiformes) Die freilebenden Gamasina (Gamasides), Raubmilben. Die Tierwelt Deutschlands 59: 1–475.
• Koch 1835–1844Koch 1835–1844:
  Koch CL. 1835–1844. Deutschlands Crustaceen, Myriapoden und Arachniden: Ein beitrag zur Deutschen fauna. Pustet, Regensburg.
• Li et al. 1999Li et al. 1999:
  Li C, Yang XZ, Chen HJ. 1999. A new species of the genus Gamasodes from China (Acari: Parasitidae). Acta Zootaxonomica Sinica 24: 156–158.
• Ma 1992Ma 1992:
  Ma LM. 1992. Descriptions of a new species and an unknown male of Gamasodes from north Qing-Zang Plateau (Acari: Mesostigmata, Parasitidae). Acta Entomologica Sinica 35: 113–116.
• Micherdzinski 1969Micherdzinski 1969:
  Micherdzinski W. 1969. Die Familie Parasitidae Oudemans 1901 (Acarina, Mesostigmata). Zakład Zoologii Systematycznej Polskiej Akademii Nauk, Krakow. 690 pp.
• Oudemans 1903Oudemans 1903:
  Oudemans AC. 1903. Acarologische Aanteekeningen. VI. Entomologische Berichten 1 (12): 83–88.
• Oudemans 1936Oudemans 1936:
  Oudemans AC. 1936. Kritisch historisch overzicht der acarologie, Deerde Gedeelte, 1805-1850. Band A (E J Brill, Leiden): 1–430.
• Oudemans 1939aOudemans 1939a:
  Oudemans AC. 1939a. Neue funde auf dem gebiete der systematik und der nomenclatur der Acari III. Zoologischer Anzeiger 126: 20–24.
• Oudemans 1939bOudemans 1939b:
  Oudemans AC. 1939b. Neue funde auf dem gebiete der systematik und der nomenklatur der Acari IV. Zoologischer Anzeiger 126: 195–201.
• Polak 1996Polak 1996:
  Polak M. 1996. Ectoparasitic effects on host survival and reproduction: The Drosophila-Macrocheles association. Ecology 77: 1379–1389.
• Polak et al. 2004Polak et al. 2004:
  Polak M, Starmer WT, Wolf LL. 2004. Sexual selection for size and symmetry in a diversifying secondary sexual character in Drosophila bipectinata Duda (Diptera: Drosophilidae). Evolution 58: 597–607.
• Samšiňák 1979Samšiňák 1979:
  Samšiňák K. 1979. Mites of Saudi Arabia Acari from Musca domestica. Fauna Saudi Arabia 1: 69–74.
• Schweizer 1961Schweizer 1961:
  Schweizer J. 1961. Die Landmilben der Schweiz (Mittelland, Jura und Alpen) Parasitiformes Reuter. Denkschriften der Schweizerischen Naturforschenden Gesellschaft 84: 1–207.
• Strenzke 1951Strenzke 1951:
  Strenzke K. 1951. Die adulten stadien von Gamasodes bispinosus und die systematische stellung der gattung Gamasodes (Acarina: Parasitiformes). Zoologischer Anzeiger 147: 13–24.
• Tian and Gu 1991Tian and Gu 1991:
  Tian QY, Gu YM. 1991. The first record of Gamasodes in China with description of a new species (Acari: Parasitidae). Acta Zootaxonomica Sinica 16: 432–435.
• Trägårdh 1910Trägårdh 1910:
  Trägårdh I. 1910. Acariden aus dem Sarekgebirge. Naturwissenschaftlichen Naturwissenschaftliche Untersuchungen des Sarakgebirges in Schwedisch-Lappland geleitet von Dr Axel Hamberg. Zoology, Stockholm 4 (Lief 4): 375–586.
• Tseng 1995Tseng 1995:
  Tseng YH. 1995. A taxonomical study of free-living gamasine mite family Parasitidae Oudemans (Acari, Mesostigmata) from Taiwan. Journal of the Taiwan Museum 48: 11–81.