Belongs within: Oripodoidea.
The Mochlozetidae are a pantropical and subtropical group of arboreal oribatid mites.
High-rise mites
Published 15 December 2024
For the most part, oribatids or beetle mites may be thought of as soil dwellers. But there are some examples of oribatids rising higher to pursue a life climbing in vegetation. Among such high risers are the members of the family Mochlozetidae.
Mochlozetids are most diverse in tropical or subtropical regions of the world where they may be found on either trees or herbaceous vegetation. At least some species have also been found on soil or leaf litter though the significance of such findings remains uncertain. Norton (1983) suggested that they may represent individuals that had fallen from living vegetation, or that they may indicate periodic vertical migrations. Some characteristic features of mochlozetids appear to be adaptations to their vegetative habitat: leg claws bear a subterminal tooth that may improve grip, and chelicerae bear an external notch that may increase their range of motion (Norton & Behan-Pelletier 2009). Features commonly, though not always, present in mochlozetids include distinct pteromorphs, reduction of the dorsal setae to fine needles or bare sockets, presence of a tutorium (a projecting tooth on the side of the prodorsum), and a median interruption in the suture separating prodorsum and notogaster.
Mochlozetids belong to the poronotic oribatids, an assemblage characterised by the presence of a series of glandular openings on the body surface known as the octotaxic system. In mochlozetids, the octotaxic system manifests as porose patches of cuticle (areae porosae), often with these areas distinguished by thickened internal margins. The function of these structures is not yet known for sure, but they are thought to produce defensive chemicals or pheromones. In most poronotic families, the arrangement of the octotaxic system is fairly consistent (indeed, the name ‘octotaxic’ refers to the typical presence of eight main glandular openings) but in mochlozetids it is surprisingly variable. The genera Mochloribatula and Drymobatoides exhibit increased numbers of areae porosae, with up to fifty pairs of minute porose areas in Drymobatoides (Ermilov & Yurtaev 2023).
Mochloribatula species also exhibit sexual dimorphism in the octotaxic system, with the areae porosae towards the rear of the body being much longer in males than in females (Behan-Pelletier 2015). What appears to be courtship behaviour has been observed in an as-yet-undescribed Mochloribatula species in which the terminal pair of areae porosae in the male are raised on tubercles. The female was observed to tap at these tubercles with her palps (giving credence to the idea they produce some kind of chemical lure). The male responded by depositing a nuptial gift on the substrate from his genital opening, walking a short way forward, and performing a handstand on the front two pairs of legs, after which the female ate the nuptial gift. What happens next has not been observed but should not be too difficult to infer.
Systematics of Mochlozetidae
Characters (Norton & Behan-Pelletier 2009): Length: 500–800 µm. Prodorsum fused to notogaster; distinct notch present antiaxially on chelicerae; tutorium present. Notogaster without conspicuous setae, three pairs of short setae in p row and seven pairs of alveoli; four or more pairs of porose areas, their limits often well defined by internally thickened border, porose areas sometimes sexually dimorphic; pteromorphs immovable.
<==Mochlozetidae |--Calugarella Balogh & Balogh 1992S04 | `--*C. sabahna (Mahunka 1987) [=Unguizetes sabahnus]S04 |--Mochlobates Norton 1984S04 | `--*M. affinis (Banks 1895) [=Oribata affinis]S04 |--Nesiotizetes Jacot 1934S04 | `--*N. adamsoni Jacot 1934S04 |--Gephyrazetes Hirauchi 1999S04 | `--*G. fasciatus Hirauchi 1999S04 |--Paralobozetes Tseng 1984S04 | `--*P. longirostralis Tseng 1984S04 |--Mahunkazetes Balogh & Balogh 1992S04 | |--*M. africanus (Mahunka 1988) [=Mochlozetes africanus]S04 | `--M. longicuspis (Balogh & Mahunka 1967) [=Podoribates longicuspis]S04 |--Dynatozetes Grandjean 1960S04 | |--*D. amplus Grandjean 1960S04 | |--D. magnus (Banks 1895) [=Oribata magna]S04 | `--D. obesus Grandjean 1960S04 |--Drymobatoides Jacot 1936NB-P09, S04 [incl. Pelokylla Adolph & Haq 1982S04, Seychellozetes Mahunka 1984S04] | |--*D. mauritius Jacot 1936S04 | |--D. benoiti (Mahunka 1984) [=Seychellozetes benoiti]S04 | `--D. malabaricus (Adolph & Haq 1982) [=Pelokylla malabarica]S04 |--Rykella Balogh 1962NB-P09, S04 | |--*R. insignis Balogh 1962S04 | |--R. asiatica Yamamoto & Aoki 2000S04 | `--R. elamellata (Berlese 1916) [=Podoribates elamellata]S04 |--Uracrobates Balogh & Mahunka 1967 [incl. Urobates Hammer 1973]S04 | |--*U. magniporosus Balogh & Mahunka 1967S04 | |--U. africanus Mahunka 1988S04 | |--U. indicus Ramani & Haq 1990S04 | `--U. pygiseta (Hammer 1973)S04 [=*Urobates pygisetaH73] |--Mochlozetes Grandjean 1930S04 | |--*M. penetrabilis Grandjean 1930S04 | |--M. asculpturatus Mahunka 1985S04 | |--M. atypicus Mahunka 1982S04 | |--M. chambrieri Mahunka 1991S04 | |--M. flatus Grandjean 1930S04 | |--M. maximus (Ewing 1908) [=Oribata maxima]S04 | |--M. officiosus Grandjean 1930S04 | `--M. saltaensis Alzuet 1989S04 |--Mochloribatula Mahunka 1978S04 | |--*M. multiporosa Mahunka 1978S04 | |--M. bahamensis Norton 1983S04 | |--M. calycifera Mahunka 1985S04 | |--M. depilis (Ewing 1909) [=Notaspis depilis]S04 | |--M. floridana (Banks 1904) [=Eremaeus floridanus]S04 | |--M. grandjeani Mahunka 1978S04 | |--M. metzi Norton 1983S04 | |--M. smithi (Woolley 1971) [=Hydrozetes smithi]NS93 | `--M. texana (Ewing 1909) [=Notaspis texana]S04 |--Unguizetes Sellnick 1925 [incl. Terrazetes Jacot 1929]S04 | |--*U. sphaerula (Berlese 1905)S04 (see below for synonymy) | |--U. clavatus Aoki 1967S04 | |--U. curypterus Wen & Zhao 1994S04 | |--U. incertus (Balogh & Mahunka 1969) [=Uracrobates incertus]S04 | |--U. inermis Mahunka 1991S04 | |--U. longiporosus (Balogh & Mahunka 1966) [=Terrazetes longiporosus]S04 | |--U. mauritius (Jacot 1936)S04 [=*Terrazetes mauritiusBB92] | |--U. reticulatus Wallwork 1965S04 | |--U. setiger (Balogh & Mahunka 1978) [=Uracrobates setiger; incl. Podoribates brasiliensis Mahunka 1983]S04 | |--U. similis Mahunka 1998S04 | `--U. yemenitica Mahunka 2000S04 `--Podoribates Berlese 1908 [incl. Cardioribates Jacot 1934, Falsolobozetes Tseng 1984, Sphaerobates Sellnick 1928]S04 |--*P. longipes (Berlese 1887)S04 (see below for synonymy) |--P. artilamellatus (Ewing 1909) [=Oribata artilamellata]S04 |--P. cuscensis (Hammer 1961) [=Sphaerobates cuscensis]S04 |--P. cuspidatus Sakakibara & Aoki 1966S04 |--P. foveolatus (Hammer 1958) [=Sphaerobates foveolatus]S04 |--P. glaber (Berlese 1916) [=Sphaerozetes (Trichoribates) glaber]S04 |--P. javensis (Willmann 1932) [=Sphaerobates javensis]S04 | |--P. j. javensisS04 | `--P. j. africanus Jacot 1940S04 |--P. laneus (Tseng 1984) [=Falsolobozetes laneus]S04 |--P. minusculus (Banks 1906) [=Galumna minuscula]S04 |--P. oriformis (Pearce 1910)S04 [=Oribata oriformisS04, *Cardioribates oriformisSN98] |--P. platensis Berlese 1916 [=P. longipes platensis]S04 |--P. pratensis (Banks 1895) [=Oribata pratensis]S04 |--P. rectus Berlese 1916S04 `--P. turgidus (Banks 1906) [=Galumna turgida]S04
*Podoribates longipes (Berlese 1887)S04 [=Oribata longipesS04; incl. Sphaerozetes gratus Sellnick 1921S04, Podoribates gratusB-PW00, *Sphaerobates gratusB61]
*Unguizetes sphaerula (Berlese 1905)S04 [=Oribata sphaerulaS04, Euzetes sphaerulaG30; incl. U. triplicatulus Grandjean 1960S04]
*Type species of generic name indicated
References
[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.
Behan-Pelletier, V. M. 2015. Review of sexual dimorphism in brachypyline oribatid mites. Acarologia 55 (2): 127–146.
[B-PW00] Behan-Pelletier, V., & D. E. Walter. 2000. Biodiversity of oribatid mites (Acari: Oribatida) in tree canopies and litter. In: D. C. Coleman, & P. F. Hendrix (eds) Invertebrates as Webmasters in Ecosystems pp. 187–202. CABI Publishing: Wallingford (UK).
Ermilov, S. G., & A. A. Yurtaev. 2023. Unguizetes (Knorozovia) ershovae (Acari, Oribatida, Mochlozetidae), a new oribatid mite subgenus and species from Mexico. Acarologia 63 (4): 1187–1196.
[G30] Grandjean, F. 1930. Oribates nouveaux de la région Caraïbe. Bulletin de la Société Zoologique de France 55: 262–284.
[H73] Hammer, M. 1973. Oribatids from Tongatapu and Eua, the Tonga Islands, and from Upolu, Western Samoa. Det Kongelige Danske Videnskabernes Selskab Biologiske Skrifter 20 (3): 1–70, 29 pls.
Norton, R. A. 1983. Redefinition of Mochloribatula (Acari: Mochlozetidae), with new species, recombinations, and notes on plant associations. Acarologia 24 (4): 449–464.
[NB-P09] Norton, R. A., & V. M. Behan-Pelletier. 2009. Suborder Oribatida. In: Krantz, G. W., & D. E. Walter (eds) A Manual of Acarology 3rd ed. pp. 430–564. Texas Tech University Press.
[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.
[SN98] Swift, S. F., & R. A. Norton. 1998. Preliminary report on oribatid mite (Acari: Oribatida) diversity in the Hawaiian Islands. Bishop Museum Occasional Papers 57: 1–44.