Tyrphonothrus seniczaki, Colloff, Matthew J., 2013

Colloff, Matthew J., 2013, Species-groups and biogeography of the oribatid mite family Malaconothridae (Oribatida: Malaconothroidea), with new species from the south-western Pacific region, Zootaxa 3722 (4), pp. 401-438 : 408-410

Tyrphonothrus seniczaki sp. nov.

( Fig. 5 )

Dimensions. Holotype female length 508 Μm, breadth 278 Μm. Ratio of prodorsum to total length: 0.3 (holotype).

Female. Prodorsum. Rostrum rounded. Rostral seta (ro) smooth, curved, setiform, thin, 26 Μm long, shorter than mutual distance, emerging from alveolus ( Fig. 5 a). Lamellar seta (le) smooth, recurved, 20 Μm long, less than half mutual distance, median of apex of broad, incurved, S-shaped prodorsal ridge. Interlamellar seta (in) smooth, setiform, thin, 108 Μm long, 10 × longer than smooth, minute seta ex. Prodorsum smooth, porose.

Notogaster. Anterior notogastral margin straight. Humeral region rounded ( Fig. 5 a). With 15 pairs of smooth, very thin setae. Setae e 2, h 1 and h 2 flagelliform apically, much longer than others (58–72 Μm). Setae of the c and d series very short (7–15 Μm); c 1 positioned on squat tubercle on anterior margin of notogaster, d 1 positioned markedly anteriorly, almost level transversely with bases of c 3; distance between c 1 and c 2 at least twice that between c 2 and c 3. Seta e 1 minute, 4 Μm long; f 2, h 3 and p 1 setiform, subequal (20–26 Μm long). Short, acutelydiagonal ridges between h 2 and h 1; otherwise ridges absent. Notogastral margins slightly narrowing anteriorly, broadest between e 2 and f 2. Setae p 3 markedly anterior of p 2. Ratio of length to breadth 1.2. Caudal margin Ushaped, rounded. Notogaster smooth.

Coxisternum. Epimeral setal formula 3-1-2-3. Epimeral setae smooth, setiform, minute; 3a, 3c, 4a – c slightly longer than others (9–12 Μm); 3b absent. Epimeral plates I rounded anterolaterally; all plates separated medially ( Fig. 5 b). Apodeme IV straight, transverse. Epimeral plate IV rounded laterally.

Anogenital Region. With six pairs of smooth, fine, flagelliform genital setae, sub-equal in length (12–18 Μm), g 1-3 closely spaced, g 4-6 spaced more broadly ( Fig. 5 b). Genital plates sub-rectangular, rounded apically; each plate 97 Μm long, 72 Μm broad. Posterior margin of genital plate transverse, overlapping adanal plate. Each adanal plate 134 Μm long, 33 Μm broad; three pairs of smooth, short, setiform adanal setae, 11–14 Μm long. One pair of anal setae 14 Μm long.

Legs. Pre-tarsi heterotridactylous.

Material examined. Wet moss, Cumberland Memorial Scenic Reserve, Victoria, 37º33'S 145º52'E, coll. R.E.

Rougley, 12.iii.1996. Holotype deposited in the Australian National Insect Collection, CSIRO Ecosystem Sciences, Canberra.

Etymology. This species is named in honour of Professor Stanisław Seniczak (Department of Ecology, University of Technology and Life Sciences, Bydgoszcz, Poland) in recognition of his contribution to acarology, particularly the study of the taxonomy, morphology and ontogeny of the Oribatida .

Remarks. Tyrphonothrus seniczaki sp. nov. differs from other members of the genus by the following combination of characters:1) the very short lamellar setae; 2) the very long interlamellar setae, 10 × longer than ex; 3) setae c 1 on the anterior margin of the notogaster; 4) setae d 1 positioned markedly anteriorly, almost level transversely with bases of c 3; 5) the minute setae e 1; 6) the thin, flagelliform setae e 2, h 1 and h 2; 7) the short, diagonal lateral notogastral ridges; 8) the epimeral setal formula 3-1-2-3; 9) with six pairs of genital setae.

Tyrphonothrus seniczaki sp. nov. is morphologically most similar to T. azumaensis Yamamoto, Kuriki & Aoki, 1993 and T. longirostrum Hammer, 1966 a in that all three species have the posterior M-shaped notogastral ridge complex reduced to only its acutely-sloping lateral elements (bearing setae h 1) and the longitudinal ridges are absent. These species have seven pairs of genital and two pairs of anal setae compared with six pairs and one pair in T. seniczaki . In the latter species setae of the c and d series and e 1 are considerably shorter than in the former two.

Figures

FIGURE 5. Tyrphonothrus seniczaki sp. nov., holotype female; a) dorsal; b) ventral.