Tyrphonothrus papuensis, 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 : 403

Tyrphonothrus papuensis sp. nov.

( Fig. 1 )

Dimensions. Holotype female length 602 Μm, breadth 328 Μm. Paratype female length 583 Μm, breadth 317 Μm. Ratio of prodorsum to total length: 0.2 (holotype).

Female. Prodorsum. Rostrum acute ( Fig. 1 a). Rostral seta (ro) smooth, curved, setiform, 28 Μm long, shorter than mutual distance. Lamellar seta (le) smooth, setiform, 40 Μm long, shorter than mutual distance, emerging from alveolus on median apex of incurved S-shaped lateral carina. Anterior portion of ridge projecting laterally. Interlamellar seta (in) smooth, flagelliform apically, 116 Μm long, slightly longer than mutual distance, 8–10 × longer than smooth seta ex. Prodorsum porose.

Notogaster. Anterior notogastral margin slightly convex ( Fig. 1 a). Humeral region obtusely angled; lyrifissure ia 19 Μm long, not associated with lateral longitudinal ridge. With 15 pairs of mostly setiform notogastral setae. Setae e 2, h 1-2 and p 2 smooth, much longer (71–122 Μm long) than others (17–64 Μm long), all of which are barbed except d 1. Setae p 3 markedly anterior of p 2; p 3 39 Μm long, extending almost as far as base of p 2 (83 Μm long). Posterior ends of median and lateral longitudinal ridges joined with transverse, shallow M-shaped ridge. Ventrally with curved ridges between p 2 and h 3 and between p 2 and the caudal margin. Notogastral margins narrowing anteriorly, caudal region broadest between f 2 and e 2. Ratio of length to breadth 1.2. Caudal margin broadly rounded. Lyrifissurae ip obtuse. Notogaster with large foveolae.

Coxisternum. Epimeral setal formula 3-1-2-3; setae smooth, setiform ( Fig. 1 b). Setae 1b, 1c and 3c 18–25 Μm long; 2–3 × length of others. Setae 3b absent; 4b in lateral position. Epimeral plates IV not fully separated; fused posteromedially; plates I with transverse median indentation. Apodeme IV straight, transverse; without blunt spine.

Anogenital Region. Genital plates with six pairs of setae, smooth, thin, flagelliform, unequal in length (g 1-2 17– 24 Μm long; g 3-6 33 –47 Μm long;), g 1-5 spaced equidistantly, g 6 2 × distance from g 4 as that from g 4 from g 3 ( Fig. 1 b). Each plate 127 Μm long, 55 Μm broad. Posterior margin of genital plate transverse; anterior margin rounded. One pair of anal setae 22 Μm long, longer than width of anal plate. Each adanal plate 116 Μm long, 33 Μm broad; three pairs of smooth, setiform adanal setae, 31–42 Μm long, longer than width of adanal plate. Anterior margin of adanal plate overlapped by posterior margin of genital plate.

Legs. Pre-tarsi heterotridactylous.

Material Examined Holotype and paratype, ANIC 411, litter, rainforest, Yawasora, nr Wewak, Papua New Guinea, ca. 50 m, coll. R.W. Taylor, 8.vii.1972. Types deposited in the Australian National Insect Collection, CSIRO Ecosystem Sciences, Canberra.

Etymology. This species is named for its country of origin, Papua New Guinea.

Remarks. Tyrphonothrus papuensis sp. nov. differs from other members of the genus by the following combination of characters: 1) the prominent anterior protruding S-shaped carinae; 2) the combination of barbed and smooth notogastral setae, with d 1, e 2 and h 1-2 smooth; 3) the very short setae c 1-3; 4) the well-developed median and lateral longitudinal ridges joining a complete M-shaped posterior ridge; 5) the well-developed foveae on the notogaster; 6) epimeral setal formula 3-1-2-3; 7) six pairs of flagelliform genital setae; 8) the long anal setae.

Tyrphonothrus papuensis sp. nov. is a member of the Crassisetosus species group (cf. below). Like T. kanaka sp. nov. and T. heterotrichus (Wallwork, 1973) , it has some of the notogastral setae smooth and the others barbed. In T. kanaka it is the p series and h 3 that are barbed, whereas in T. papuensis it is the longer setae (e 2, h 1-2, p 2) that are smooth and the others are barbed; a character state it shares with T. heterotrichus with which it also shares six pairs of genital setae, the relative lengths of the notogastral setae and the foveolate notogaster. They differ in that T. heterotrichus has the alveoli of a second pair of anal setae, lacks the lateral longitudinal ridges and the M-shaped posterior ridge appears to be incomplete.

Figures

FIGURE 1. Tyrphonothrus papuensis sp. nov., holotype female; a) dorsal; b) ventral.