Galumnoidea

 Orthogalumna terebrantis, from here.

Belongs within: Poronoticae.
Contains: Galumnopsis, GalumnellaAllogalumna, Acrogalumna, Pilogalumna, Pilizetes, Trichogalumna, Pergalumna, Galumna.

The Galumnidae is a diverse family of oribatid mites with large pteromorphs on either side of the notogaster that can hinge downwards to cover the legs. The prodorsum lacks true lamellae, but sclerotised lamellar lines and usually sublamellar lines are present in the subfamilies Galumninae and Pergalumninae. These two subfamilies are distinguished by the position of the lamellar setae, which are laterad to the lamellar line in Galumninae but mediad to it in Pergalumninae (Balogh & Balogh 1992). The members of the third subfamily, Allogalumninae, lack the lamellar lines, though the sublamellar lines are present in most genera except Disparagalumna, Psammogalumna and Pilogalumna (Balogh & Balogh 1992).

The Galumnellidae are a group of galumnoid oribatid mites with slender chelicerae and an acuminate rostrum. The notogaster of galumnellids is commonly sculptured, though it is is smooth in Galumnopsis sensu stricto (Balogh & Balogh 1992).

On a wing and a mite
Published 25 January 2011
Dorsal and ventral views of Monogalumnella neotricha, with legs removed, from Balogh & Balogh (1992).

Oribatid mites come in a wide range of varieties, and the animal in the figures above is a member of the oribatid family Galumnellidae. Galumnellids belong to a group of oribatids, the galumnoids, marked by their well-developed pteromorphs: the roughly triangular structures at either side of the front of the body. Many oribatids have pteromorphs developed to a greater or lesser degree, but the pteromorphs of galumnoids are particularly noteworthy for their size and for the development of a hinge between the pteromorph and the main body, so that the pteromorph can be folded down to cover the legs for protection (other species have the pteromorphs as fixed outgrowths of the body). The name ‘pteromorph’, of course, means ‘wing-shaped’, and you can readily find cases where galumnoids have been referred to as ‘winged mites’ (especially in older publications). Woodring (1962) even suggested that galumnoids might provide a useful analogy for the evolution of wings in insects. However, pteromorphs are not actually wings like those of insects, being used only for protection, not flight. In animals as small as oribatids, the relative viscosity of the air becomes very high, not to mention the relative force of small air movements. Vary small arthropods that move aerially either develop long hairs or similar structures so that they can be passively lifted and carried by the breeze (like the line of silk produced by ballooning spiders) or have reduced wings with long fringes of hairs to maintain wing surface area while minimising air resistance (such as mymarid wasps, thrips or ptiliid beetles). A solid plate like the galumnoid pteromorph would be to difficult to move*.

*Similar issues affect suggestions that the absent fossil record of the earliest winged insects may indicate that flight evolved at small sizes. It seems almost certain that the first flying insects were relatively large.

The Galumnellidae can be distinguished from other galumnoid mites by the lack of protruding lamellae on the prodorsum (the top of the ‘head’), the pointed rather than rounded rostrum, and the shape of their chelicerae. The chelicerae of galumnellids are long and slender, compared to the shorter, stronger chelicerae of their relatives in the Galumnidae. Galumnella has been shown in the laboratory to be panphytophagous (Badejo & Akinwole 2007)—that is, it will accept any type of plant or algal food, both living and dead.

Systematics of Galumnoidea
<==Galumnoidea
    |--GalumnellidaeS04
    |    |--GalumnopsisS04
    |    |--GalumnellaS04
    |    |--Monogalumnella Mahunka 1986S04
    |    |    `--*M. neotricha Mahunka 1986S04
    |    |--Iberogalumnella Arillo & Subías 1993S04
    |    |    `--*I. alandalusica Arillo & Subías 1993S04
    |    `--Trypogalumnella Mahunka 1995S04
    |         |--*T. poronota Mahunka 1995S04
    |         `--T. densoporosa Mahunka 1995S04
    `--Galumnidae [Galumnatidae]SK10
         |  i. s.: Kinezogalumna Aoki & Hu 1993S04
         |           `--*K. calcicola Aoki & Hu 1993S04
         |         Trichogalumnella Mahunka 1992S04
         |           `--*T. hauseri Mahunka 1992S04
         |--AllogalumninaeBB92
         |    |--AllogalumnaS04
         |    |--AcrogalumnaBB92
         |    |--PilogalumnaBB92
         |    |--Aegyptogalumna Al-Assiuty, Abdel-Hamid et al. 1985BB92
         |    |    `--*A. mastigophora Al-Assiuty, Abdel-Hamid et al. 1985S04
         |    |--Globogalumna Balogh & Balogh 1989BB92
         |    |    `--*G. globulifera (Balogh & Mahunka 1978) [=Allogalumna globulifera]S04
         |    |--Xenogalumna Balogh 1961BB92, S04
         |    |    `--*X. longula Balogh 1961S04
         |    |--Disparagalumna Hammer 1973BB92
         |    |    `--*D. tongaensis Hammer 1973S04
         |    |--Leptogalumna Balogh 1960BB92
         |    |    |--*L. ciliata Balogh 1960S04
         |    |    `--L. reducta Mahunka 1996S04
         |    |--Psammogalumna Balogh 1943BB92
         |    |    |--*P. hungarica (Sellnick 1925) [=Stictozetes hungaricus]S04
         |    |    `--P. thysanura (Krivolutskaja 1952) [=Allogalumna thysanura]S04
         |    `--Cryptogalumna Grandjean 1957BB92
         |         |--*C. cryptodonta Grandjean 1957S04
         |         `--C. grandjeani Balakrishnan & Haq 1985S04
         |--PergalumninaeBB92
         |    |--PilizetesBB92
         |    |--TrichogalumnaBB92
         |    |--PergalumnaS04
         |    |--Didymonycha Mahunka 1984BB92
         |    |    `--*D. hesperis Mahunka 1984S04
         |    |--Taeniogalumna Balogh 1962BB92
         |    |    |--*T. sphaerula Balogh 1962S04
         |    |    `--T. tanzanica Mahunka 1983S04
         |    |--Heterogalumna Balogh 1960BB92
         |    |    |--*H. lineolata Balogh 1960S04
         |    |    |--H. monticola Balogh 1962S04
         |    |    `--H. pygmaea (Balogh 1958) [=Galumna pygmaea]S04
         |    |--Carinogalumna Engelbrecht 1973BB92 (see below for synonymy)
         |    |    |--*C. montana Engelbrecht 1973S04
         |    |    |--C. clericata (Berlese 1914) [=Oribata clericata]S04
         |    |    `--C. genavensium (Mahunka 1998) [=Paracarinogalumna genavensium]S04
         |    |--Orthogalumna Balogh 1961BB92, S04 [incl. Mirogalumna Mahunka 1993S04]
         |    |    |--*O. saeva Balogh 1961S04
         |    |    |--O. terebrantis Wallwork 1965S04
         |    |    `--O. xena (Mahunka 1993)S04 [=*Mirogalumna xenaM93]
         |    `--Stictozetes Berlese 1916BB92 [incl. Strabogalumna Mahunka 1995S04, Trachygalumna Balogh 1960S04]
         |         |--*S. scaber (Berlese 1916)S04 [=Oribata (*Stictozetes) scaberS04, Oribates (*S.) scaberBB92]
         |         |--S. bisulcatus (Balogh 1960)S04 [=*Trachygalumna bisulcataBB92]
         |         |--S. margaritae (Mahunka 1993) [=Trachygalumna margaritae]S04
         |         |--S. microporosus (Mahunka 1986) [=Trachygalumna microporosa]S04
         |         |--S. psadilliferus (Mahunka 1995) [=Strabogalumna psallidifera]S04
         |         `--‘Trachygalumna’ punctulata Bal. 1960B61
         `--GalumninaeBB92
              |--GalumnaS04
              |--Centroribates Berlese 1914BB92
              |    `--*C. mucronatus (Canestrini & Canestrini 1882)S04 [=Oribata mucronataS04, Oribates mucronatusM98]
              |--Rostrogalumna Engelbrecht 1973BB92
              |    `--*R. ‘rostrata’ (Engelbrecht 1969) [=Galumna rostrata non Sellnick 1922]S04
              |--Sphaerogalumna Balogh 1961BB92
              |    `--*S. index (Balogh 1960) [=Pergalumna index]S04
              |--Sacculogalumna Engelbrecht 1973BB92
              |    `--*S. saccularis Engelbrecht 1973S04
              |--Neogalumna Hammer 1973BB92
              |    |--*N. antenniger Hammer 1973S04
              |    `--N. curviporosa Balakrishnan 1986S04
              |--Setogalumna Balogh 1985BB92
              |    |--*S. excellens Balogh 1985S04
              |    `--S. diminuta Arillo & Subías 1993S04
              |--Dicatozetes Grandjean 1956BB92
              |    |--*D. uropygium (Grandjean 1928) [=Centroribates uropygium]S04
              |    `--D. numidicus Bernini 1984S04
              |--Flagellozetes Balogh 1970BB92
              |    `--*F. porosus Balogh 1970S04
              |         |--F. p. porosusS04
              |         `--F. p. indicus Balakrishnan & Haq 1985S04
              |--Dimidiogalumna Engelbrecht 1972BB92
              |    |--*D. villiersensis Engelbrecht 1972S04
              |    |--D. azumai Aoki 1996S04
              |    `--D. comoroensis Mahunka 1994S04
              |--Notogalumna Sellnick 1959BB92
              |    |--*N. praetiosa Sellnick 1959S04
              |    |--N. africana Mahunka 1988S04
              |    |--N. nortoni Ramani & Haq 1990S04
              |    `--N. truncata (Warburton 1912) [=Oribata truncata]S04
              `--Vaghia Oudemans 1919BB92
                   |--*V. stupenda (Berlese 1916)S04 [=Oribates (Stictozetes) stupendusB16]
                   |--V. blascoi Travé 1981S04
                   |--V. carinata (Travé 1956) [=Galumna carinata]S04
                   |--V. simplex Travé 1957S04
                   `--V. uniporosa Arillo & Subías 1993S04

Carinogalumna Engelbrecht 1973BB92 [incl. Paracarinogalumna Mahunka 1998S04, Pseudogalumna Pérez-Íñigo & Baggio 1994S04]

*Type species of generic name indicated

References

Badejo, M. A., & P. O. Akinwole. 2007. Preliminary study of the feeding habits of seven species of oribatid mites from Nigeria. Systematic and Applied Acarology 12: 121–125.

[B61] Balogh, J. 1961. Identification keys of world oribatid (Acari) families and genera. Acta Zoologica Hungarica 1: 243–344.

[BB92] Balogh, J., & P. Balogh. 1992. The Oribatid Mites Genera of the World vol. 1. Hungarian Natural History Museum: Budapest.

[B16] Berlese, A. 1916. Centuria terza di Acari nuovi. Redia 12: 289–338.

[M93] Mahunka, S. 1993. Some data to the oribatid fauna of Rwanda (Acari: Oribatida). Revue Suisse de Zoologie 100 (1): 75–89.

[M98] Michael, A. D. 1898. Oribatidae. In: H. Lohmann (ed.) Das Tierreich. Eine Zusammenstellung und Kennzeichnung der rezenten Tierformen vol. 3. Acarina pp. 1–93. R. Friedländer und Sohn: Berlin.

[SK10] Schäffer, S., S. Koblmüller, T. Pfingstl, C. Sturmbauer & G. Krisper. 2010. Ancestral state reconstruction reveals multiple independent evolution of diagnostic morphological characters in the “Higher Oribatida” (Acari), conflicting with current classification. BMC Evolutionary Biology 10: 246.

[S04] Subías, L. S. 2004. Listado sistemático, sinonímico y biogeográfico de los ácaros oribátidos (Acariformes, Oribatida) del mundo (1758–2002). Graellsia 60 (número extraordinario): 3–305.

Woodring, J. P. 1962. Oribatid (Acari) pteromorphs, pterogasterine phylogeny, and evolution of wings. Annals of the Entomological Society of America 55 (4): 394–403.

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