Tyrphonothrus gringai, Colloff, Matthew J. & Cameron, Stephen L., 2013

Colloff, Matthew J. & Cameron, Stephen L., 2013, A phylogenetic analysis and taxonomic revision of the oribatid mite family Malaconothridae (Acari: Oribatida), with new species of Tyrphonothrus and Malaconothrus from Australia, Zootaxa 3681 (4), pp. 301-346 : 309-313

Tyrphonothrus gringai sp. nov.

( Figs. 4–6 )

Dimensions. Holotype female length 542 μm, breadth 306 μm; paratypes (n = 17) mean length 569 μm (range 542–588 μm); mean breadth 298 μm (range 277–309 μm). Ratio of prodorsum to total length: 0.31 (holotype).

Female. Prodorsum. Rostrum rounded, smooth, porose ( Fig. 4 a). Rostral seta (ro) slightly barbed, curved, setiform, 34 μm long, longer than mutual distance, emerging from alveolus. Lamellar seta (le) barbed, setiform, 68 μm long, twice length of mutual distance, on apex of incurved, S-shaped lateral carina. Interlamellar seta (in) barbed, flagelliform, 128 μm long, longer than mutual distance. Exobothridial seta ex barbed, 3 × shorter than in. Prodorsum finely porose, with well-developed posterior transverse ridge and medial curved ridges extending from in to posterior of le.

Notogaster. Dorsosejugal suture slightly convex ( Fig. 4 a). Humeral region broadly rounded. With 15 pairs of barbed, setiform setae. Setae e 2, h 1-2 and p 1-3 much longer than others. Seta c 1 36 μm long, shorter than distance to d 1; c 2 32 μm long, shorter than distance to cp; c 3 28 μm long, shorter than distance to cp; cp 24 μm long, shorter than distance to d 2; d 1 43 μm, shorter than mutual distance; d 2 21 μm, shorter than distance to e 2; e 1 36 μm long, shorter than mutual distance; e 2 86 μm, longer than distance to f 2; f 2 20 μm long, shorter than distance to h 2; h 1 64 μm long, longer than distance to p 1; h 2 93 μm long, longer than distance to p 1; h 3 36 μm long; p 1 47 μm long, shorter than mutual distance; p 1 positioned dorsally; p 3 60 μm long, extending beyond base of p 2 (81 μm long). With relatively narrow median longitudinal ridges joined with narrow posterior M-shaped ridge. Paired lateral longitudinal ridges present. With curved ridge between bases of setae p 1, between p 1 and h 2 and between h 2 and f 2. With longitudinal ridges lateral of anal and genital plates. Notogastral margins narrowing anteriorly, caudal region broadest between f 2 and e 2. Ratio of length to breadth 1.21. Caudal margin broadly rounded. With short concave ridges between h 3 and p 2 and between p 2 and posterior margin of notogaster. Lyrifissurae ip transverse. Notogaster densely porose; cerotegument granular.

Subcapitulum. Seta h on mentum barbed, curved, 16 μm long ( Fig. 5 a). Genal seta a barbed, 19 μm long; seta m smooth, 15 μm long. Smooth coxal spine (e). Palp setal formula (solenidion in brackets) 0-1-3-9(1); palp tarsus 14 μm long, rounded apically ( Fig. 5 b); eupathidial seta sul lozenge-shaped apically, pointed; solenidion ω curved bacilliform. Seta d on tibia short, squat, conical. Cheliceral setae Pb and cha curved, barbed, sub-equal in length ( Fig. 5 c).

Coxisternum. Epimeral setal formula 3-1-3-3 ( Fig. 4 b). Epimeral setae 3b, 3c, and 4a-c barbed, setiform, the rest smooth; Setae on epimeral plates I and II 9–13 μm long, 1c in mediolateral position; setae 3b, 3c and 4a–c longer than others (18–27 μm); 3b in posteriolateral position; 4b in posteriolateral position. Epimeral plates I partly fused medially, rounded anteriolaterally. Epimeral plates II rounded posteriolaterally, partly fused medially. Epimeral plates III and IV separated medially. Epimere I widest; IV wider than III. Apodeme IV straight, transverse; with blunt spine laterally.

Anogenital Region. With five pairs of long, barbed, genital setae, flagelliform apically 34–47 μm long ( Fig. 4 b); g 1-3, closely spaced, g 4 and g 5 spaced further apart; g 5 directed posteriorly; all setae shorter than width of genital plate. Each genital plate 128 μm long, 25 μm broad, without well-developed median carina, broadest medially, narrowing anteriorly and posteriorly. Posterior margin of genital plate transverse. One pair of anal setae 15 μm long. Each adanal plate 118 μm long, 36 μm broad; three pairs of barbed, setiform adanal setae, 34–41 μm long, longer than width of adanal plate; ad 1 not on median carina. Anterior margin of adanal plate acute, overlapped by posterior margin of genital plate, without thickened transverse ridge.

Legs. Pre-tarsi homotridactylous; claws smooth ( Fig. 6 ). Tarsi long and thin ratio of lengths to breadth of tarsi: I 2.92; II 2.23; III 4.08; IV 4.36. Setal formula: Leg I 1-5 -3(1)-4(1)-11(3); Leg II 1-4 -2(1)-3(1)-10(1); Leg III 2-3 - 1-2(1)-10; Leg IV 1-2 -1-2-9. Most setae of tibiae, genuae and femora barbed; most tarsal setae smooth. Tarsus I with proral setae (p) short, broad basally, flagelliform apically ( Fig. 6 a): setae p on other tarsi short, blunt, smooth or barbed. Unguinal setae (u) short, blunt, broad. Solenidia (ω1-3) clustered; famulus (ε) thin, setiform 5 μm long. Fastigial setae (ft) homeomorphic: long, curved, barbed and pointed. Setae ft ” and ft ’ on tarsi II and III similarly shaped to those on tarsus I ( Figs 6 b,c). Tarsus IV with seta ft ” curved, pointed, smooth, 18 μm long; seta s same shape and length as pv ” ( Fig. 6 d).

Material examined. Holotype, 17 paratypes, ANIC 756 Moss on rock faces, Nothofagus and Eucalyptus forest, Dilgry River, Barrington Tops State Forest, New South Wales, 31°53'22"S 151°32'17"E, 1180 m., coll. T. Weir & A Calder, 15–16.xi.1981. Holotype and paratypes deposited in the Australian National Insect Collection, CSIRO Ecosystem Sciences, Canberra.

Etymology. This species is named for the Gringai clan of the Wanaruah People, Aboriginal inhabitants of the Barrington Tops and Williams River District, on whose ancestral land this species was found.

Remarks. Tyrphonothrus gringai sp. nov. differs from other members of the genus by the following combination of characters: 1) the densely porose notogaster; 2) with setae e 2, h 1-2 and p 1-3 much longer than others; 3) the centrodorsal and laterodorsal ridges linked with M-shaped posterior ridges; 4) the pear-shaped notogaster; 5) the barbed idiosomal setae (the anal setae, those on epimeres I and II and 3a are smooth); 6) with five pairs of genital setae sub-equal in length.

Tyrphonothrus gringai sp. nov., like T. gnammaensis , is one of a small group of species that have five pairs of genital setae (see remarks section for T. gnammaensis above). It is close to T. fijiensis , T. maritimus sp. nov. and T. taylori sp. nov. But the former two have smooth exobothridial, epimeral and genital setae; whereas T. taylori has densely-spaced foveolae on the notogaster, more pronounced S-shaped prodorsal ridges and much longer setae h 1, h 2 and 1c (cf. below).

Figures

FIGURE 4. Tyrphonothrus gringai sp. nov., holotype female; a) dorsal; b) ventral.

FIGURE 5. Tyrphonothrus gringai sp. nov., holotype female; a) subcapitulum; b) palp; c) chelicera.

FIGURE 6. Tyrphonothrus gringai sp. nov., holotype female, left legs, antiaxial view; a) Leg I; b) Leg II; c) Leg III; d) Leg IV.