Parachipteria nivalis ( Hammer, 1952 )

Bayartogtokh, B. & Ryabinin, N. A., 2012, The Soil Mite Family Achipteriidae (Acari: Oribatida) In Mongolia And The Russian Far East, Acarologia 52 (2), pp. 135-156 : 145-147

Parachipteria nivalis ( Hammer, 1952)

( Fig. 6 )

Achipteria nivalis: Hammer, 1952: 64 , fig. 103.

Parachipteria nivalis: Shaldybina, 1975: 342 , fig. 859; Marshall et al., 1987: 328.

Campachipteria nivalis: sensu Subías, 2004: 168 .

Diagnosis — With character states of Parachipteria (see Balogh and Balogh, 1992 and Weigmann, 2006 for generic diagnosis); total length 510 – 640 µm, dorsal and ventral plates with minute granular cerotegument; lamella fused medially, lamellar cusp with large lateral dens; sensillus with clubshaped head, finely barbed; notogastral porose areas small, but clearly visible; coxisternal setal formula 3-1-3-2; tutorium narrow, slightly widening anteriorly in long cusp not pointed distally; pedotectum I without anterior tooth.

Measurements — Body length: 533 – 640 (569) µm, length of notogaster 422 – 494 (449) µm, width of notogaster 322 – 439 (362) µm.

Integument — Body color dark brown, strongly sclerotized species with minute microtubercles on prodorsum, notogaster and podosomal region. Granular cerotegument clearly evident on notogaster, subcapitular mentum, at base of prodorsum and ventral plate.

Dorsal aspect — Rostrum rounded in dorsal view, but slightly projected and curved ventrally in lateral view. Rostral seta long, barbed, curving medially, and extending well beyond tip of rostrum. Lamellae fused medially, with large cusp; lateral dens of cusp large, pointed distally. Lamellar seta nearly as long as ro, moderately thick, but smooth, inserted medially on ventral side of lamellar cusp. Interlamellar seta long, fairly thick, barbed, slightly extending anteriorly beyond tip of lamella ( Fig. 6A ). Exobothridial seta minute, hardly discernable. Sensillus with slightly expanded club-shaped head about half total length, smooth or minutely barbed ( Fig. 6E ). Notogaster slightly longer than wide, ratio 1.2:1, robust in lateral view; anterior margin rounded or subtriangular, posterior margin broadly rounded. Lenticular region weakly visible and lacking true lenticulus. Notogastral setae medium long, thin, smooth; setae c and la conspicuously longer than other setae. Porose areas round to oval in shape, Aa and A1 slightly larger than two others; lyrifissures not evident. Lateral edge of pteromorph smooth, without striations ( Fig. 6A ).

Lateral aspect — Tutorium narrow, appearing pointed in dorsal aspect, but slightly widening anteriorly in distinct cusp not sharply pointed distally ( Fig. 6C ). Genal tooth sharply pointed distally, with genal notch extending posterior to insertion of seta ro. Pedotectum I well developed, fully covering acetabulum I, without anterior tooth ( Fig. 6D ); pedotectum II small, ear-shaped, covering less than a quarter of acetabulum II.

Ventral aspect — Subcapitular mentum with granular cerotegument; setae h, m and a medium long, smooth. Capitular angle of coxisternum not projecting. Chelicera chelate-dentate. Axillary saccule absent from base of palp. Epimeral setae relatively long, thin, smooth, 1b longest, setae 1c and 3c represented by their alveoli, seta 4c not evident; formula 3-1-3-2. Six pairs of genital, one pair of aggenital, two pairs of anal and three pairs of adanal setae thin, smooth. Lyrifissure iad adjacent and parallel to anal aperture ( Fig. 6B ).

Legs — Each tarsus with large empodial claw and thin, longer lateral claws serrated dorsally. Formula of setation, including famulus: I (1-5-3-4-20), II (1-5-3-4-15), III (2-3-1-3-15), IV (1-2-2-3-12), formula of solenidia I (1-2-2), II (1-1-2), III (1-1-0), IV (0-1-0).

Material examined — Three specimens (females): Basin river Minj Gol, Mts. Khentii, District Batshireet, Province Khentii, Mongolia, mosses growing on bark of larch tree trunk, 49 o 15’N, 108 o 40’E, 1420 m. a.s.l., 27 July 2002, Col. B. Bayartogtokh.

Remarks — The character states of specimens examined here accord well with those studied by Hammer (1952) and Shaldybina (1975) from North America and Europe, respectively, and some supplementary characteristics are provided here. Subías (2004) included P. nivalis in the genus Campachipteria Aoki, 1995 , but this combination is not acceptable as the latter genus being with monodactylous legs, while Parachipteria have tridactylous legs, and therefore, P. nivalis can not be a member of the former genus.

Figures

FIGURE 6: Parachipteria nivalis (Hammer, 1952): A – Dorsal view of idiosoma, legs omitted; B – Ventral view of idiosoma, legs omitted; C – Tutorium, right, lateral view; D – Pedotectum I, right, lateral view; E – Sensillus and bothridium, lateral view.