Ptyctima

Lateral view of dorsal plates (A) and ventral plates (B) of Microtritia minima, from Balogh & Balogh (1992, The Oribatid Mites Genera of the World vol. 2).

Belongs within: Acariformes.
Contains: Austrotritia, Mesotritia, Oribotritia, Indotritia, Euphthiracarus, Acrotritia, Phthiracaridae.

The Ptyctima are a group of oribatid mites with a ptychoid body plan: that is, the legs can be fully withdrawn and the aspis rotated ventrad to cover the legs against the notogaster and ventral plate. Two major lineages are recognised in the Ptyctima, the Phthiracaridae and Euphthiracaroidea.

The Euphthiracaroidea are a group of ptychoid mites in which the body is strongly compressed laterally. Retraction of the legs is facilitated by relaxation of the notogaster to increase its volume (Norton 2001). In the family Synichotritiidae, the genital setae are in an antaxial position, in groups or transverse rows, while the Oribotritiidae and Euphthiracaridae both have the genital setae in a paraxial position, in a longitudinal row. The latter two families are distinguished in that the Euphthiracaridae have the ventral (anal and genital) plates fused into a single plate pair, while the Oribotritiidae have them at least partially separated. In the Bornean Temburongia patoi, the sides of the notogaster are produced ventrolaterally into two lobes that contact each other medially, in contrast to the simple notogastral margins leaving the V-shaped ventral region exposed in other genera (Balogh & Balogh 1992).

<==Ptyctima [Euptyctima] PL17
    |--Euphthiracaroidea DW10
    |    |--Synichotritiidae S04
    |    |    |--Apotritia Norton & Lions 1992 S04
    |    |    |    `--*A. walkeri Norton & Lions 1992 S04
    |    |    |--Temburongia Mahunka 1990 [Temburongiidae] S04
    |    |    |    `--*T. patoi Mahunka 1990 S04
    |    |    |--Synichotritia Walker 1965 S04
    |    |    |    |--*S. caroli Walker 1965 S04
    |    |    |    |--S. longipila Niedbała 2002 S04
    |    |    |    |--S. parvipilosa Niedbała 2002 S04
    |    |    |    `--S. spinulosa Walker 1965 S04
    |    |    `--Sabahtritia Mahunka 1987 S04
    |    |         |--*S. hauseri Mahunka 1987 S04
    |    |         |--S. foveolata (Hu, Wang & Aoki 1991) [=Synichotritia foveolata] S04
    |    |         |--S. furcata (Hu & Wang 1992) [=Synichotritia furcata] S04
    |    |         |--S. lienhardi Mahunka 1995 S04
    |    |         |--S. mirabilis Mahunka 1991 S04
    |    |         |--S. sarawak Mahunka 1996 S04
    |    |         `--S. tianmuensis (Hu, Wang & Aoki 1991) [=Synichotritia tianmuensis] S04
    |    |--Oribotritiidae S04
    |    |    |--Austrotritia S04
    |    |    |--Mesotritia S04
    |    |    |--Oribotritia S04
    |    |    |--Indotritia S04
    |    |    |--Paratritia Moritz 1966 S04
    |    |    |    `--*P. baloghi Moritz 1966 S04
    |    |    |--Terratritia Ramsay & Sheals 1969 S04
    |    |    |    |--*T. askewi Ramsay & Sheals 1969 S04
    |    |    |    `--T. seconda Mahunka 1991 S04
    |    |    |--Sabacarus Ramsay & Sheals 1969 S04
    |    |    |    |--*S. corneri Ramsay & Sheals 1969 [incl. S. ranokaoensis Hammer 1970] S04
    |    |    |    `--S. japonicus Shimano & Aoki 1997 S04
    |    |    |--Maerkelotritia Hammer 1967 S04
    |    |    |    |--M. kishidai (Aoki 1958) S04 (see below for synonymy)
    |    |    |    |--M. crytopa (Banks 1904) S04 (see below for synonymy)
    |    |    |    `--M. krivolutskyi Märkel 1968 S04
    |    |    |         |--M. k. krivolutskyi S04
    |    |    |         `--M. k. mongolica Mahunka 1981 S04
    |    |    `--Protoribotritia Jacot 1938 S04
    |    |         |--*P. canadaris Jacot 1938 S04
    |    |         |--P. aberrans (Märkel & Meyer 1959) [=Oribotritia aberrans] S04
    |    |         |--P. africana Mahunka 1985 S04
    |    |         |--P. ensifer Aoki 1969 [=P. aberrans ensifer] S04
    |    |         `--P. oligotricha Märkel 1963 S04
    |    `--Euphthiracaridae [Euphthiracarini] S04
    |         |--Euphthiracarus S04
    |         |--Acrotritia S04
    |         |--Bukitritia Mahunka 1990 S04
    |         |    `--*B. timah Mahunka 1990 S04
    |         |--Sumatrotritia Mahunka 1989 S04
    |         |    |--*S. inusitata Mahunka 1989 S04
    |         |    |--S. elegans Mahunka 1991 S04
    |         |    `--S. murphyi Mahunka 1999 S04
    |         `--Microtritia Märkel 1964 S04
    |              |--*M. minima (Berlese 1904) (see below for synonymy) S04
    |              |--M. contraria Niedbała 1993 S04
    |              |--M. fissurata Märkel 1968 S04
    |              |--M. fusa Niedbała 2000 S04
    |              |--M. glabrata Niedbała 1993 S04
    |              |--M. hauseri Mahunka 1993 [incl. M. altissima Mahunka 1994] S04
    |              |--M. hawaiiensis Niedbała 1994 S04
    |              |--M. incisa Märkel 1964 S04
    |              |--M. neonominata Subías 2004 [=M. glabrata Starý 1993 non Niedbała 1993] S04
    |              |--M. schusteri Märkel 1964 S04
    |              |--M. similis N01
    |              |--M. simplex (Jacot 1930) S04 (see below for synonymy)
    |              |--M. striatissima Mahunka 1999 S04
    |              |--M. tropica Märkel 1964 S04
    |              |    |--M. t. tropica [incl. M. ethiopica Mahunka 1988] S04
    |              |    `--M. t. dusan Ramsay & Sheals 1969 S04
    |              `--M. tumida Niedbała 1988 S04
    `--+--Phthiracaridae DW10
       `--Nehypochthonius Norton & Metz 1980 PL17, S04 [Nehypochthoniidae, Nehypochthonoidea]
            |--*N. porosus Norton & Metz 1980 S04
            `--N. yanoi Aoki 2002 S04

Maerkelotritia crytopa (Banks 1904) S04 [=Phthiracarus crytopus S04; incl. Oribotritia gibbera Walker 1965 S04, Maerkelotritia gibbera A80, Phthiracarus maximus Ewing 1913 S04]

Maerkelotritia kishidai (Aoki 1958) S04 [=Oribotritia kishidai S04; incl. *M. alaskensis Hammer 1967 S04, O. sellnicki Walker 1965 S04, M. sellnicki A80]

*Microtritia minima (Berlese 1904) [=Phthiracarus minimus; incl. Tritia (Pseudotritia) minuta Willmann 1919, Microtritia silofila Subías 1975] S04

Microtritia simplex (Jacot 1930) S04 [=Pseudotritia simplex S04; incl. Rhysotritia paeneminima Walker 1965 S04, Microtritia paeneminima NP91]

*Type species of generic name indicated

REFERENCES

[A80] Aoki, J. 1980. A revision of the oribatid mites of Japan. I. The families Phthiracaridae and Oribotritiidae. Bulletin of the Institute of Environmental Science and Technology, Yokohama National University 6 (2): 1–89.

[DW10] Dabert, M., W. Witalinski, A. Kazmierski, Z. Olszanowski & J. Dabert. 2010. Molecular phylogeny of acariform mites (Acari, Arachnida): strong conflict between phylogenetic signal and long-branch attraction artifacts. Molecular Phylogenetics and Evolution 56 (1): 222–241.

[N01] Niedbała, W. 2001. Study of the diversity of Ptyctima (Acari: Oribatida) and quest for centres of its origin: the fauna of the Oriental and Australian regions. In: Halliday, R. B., D. E. Walter, H. C. Proctor, R. A. Norton & M. J. Colloff (eds) Acarology: Proceedings of the 10^th International Congress pp. 143–148. CSIRO Publishing: Melbourne.

[NP91] Norton, R. A., & S. C. Palmer. 1991. The distribution, mechanisms and evolutionary significance of parthenogenesis in oribatid mites. In: Schuster, R., & P. W. Murphy (eds) The Acari: Reproduction, development and life-history strategies pp. 107–136. Chapman & Hall: London.

[PL17] Pachl, P., A. C. Lindl, A. Krause, S. Scheu, I. Schaefer & M. Maraun. 2017. The tropics as an ancient cradle of oribatid mite diversity. Acarologia 57 (2): 309–322.

[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.