Tyrphonothrus maritimus, 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 : 313-314

Tyrphonothrus maritimus sp. nov.

(Figs. 7, 8)

Dimensions. Holotype female length 596 μm, breadth 293 μm. Ratio of prodorsum to total length: 0.24.

Female. Prodorsum. Rostrum acute, projecting apically beyond margin of prodorsum, giving impression of partial, transverse rostral ridge (Fig. 7a). Rostral seta (ro) smooth, curved, setiform, thick, 57 μm long, longer than mutual distance, emerging from well-developed tubercles. Lamellar seta (le) barbed, flagelliform apically, 97 μm, longer than their mutual distance, enclosed by incurved, S-shaped lateral carina. Interlamellar seta (in) smooth, setiform, short (92 μm), 3 × longer than smooth seta ex 1. Prodorsum granular with scattered small foveolae.

Notogaster. Dorsosejugal suture slightly convex (Fig. 7a). Humeral region obtusely angled, almost at right angles; with short ridge between setae c 2 and c 3 extending towards cp. With 15 pairs of barbed, thick, setiform setae. Setae e 2, h 2 and p 2 much longer than others. Seta c 1 51 μm long, almost equal distance to d 1; c 2 52 μm long, shorter than distance to cp; c 3 65 μm long, almost equal distance to cp; cp 62 μm, longer than distance to d 2; d 1 48 μm, almost equal their mutual distance; d 2 59 μm, equal distance to e 2; e 1 54 μm long, almost equal their mutual distance; e 2 124 μm, overlapping f 2; f 2 78 μm long, almost equal distance to h 2; h 1 65 μm long, half distance to p 1; h 2 105 μm long, half distance to p 1; h 3 95 μm long; p 1 43 μm long, half mutual distance, positioned dorsally; p 3 86 μm long, extending as far as p 2; seta p 2 121 μm long). Notogaster with complex series of median and lateral longitudinal ridges, converging anterior of h 1; then with posterior M-shaped ridge diverging medially, anterior of p 1. Lateral ridges diverging anteriorly. Margins narrowing anteriorly, broadest between e 2 and f 2. With short concave ridges between h 3 and p 2 and between p 2 and posterior margin of notogaster. Ratio of length to breadth 1.53. Caudal margin V-shaped, indented at level of seta h 2. Notogaster with small foveae.

Coxisternum. Epimeral setal formula 3-1-3-2 (Fig. 7b). Epimeral setae smooth, setiform; 1b, 3a–c, 4a and 4c longer than others (22–31 μm); 3b in posteriolateral position; 4b absent. Epimeral plates I not fused medially, rounded anteriolaterally. Epimeral plates II acute posteriolaterally, not fused medially. Epimeral plates III fused medially. Apodeme IV arched. Epimeral plate IV rounded laterally.

Anogenital Region. With five pairs of smooth, flagelliform genital setae; g 1-4 subequal in length (51–64 μm), g 1-4 closely spaced, g 5 shorter (38 μm) and spaced more broadly apart (Fig. 7b). Genital plates sub-rectangular, rounded apically; each plate 151 μm long, 48 μm broad. Posterior margin of genital plate transverse, overlapping adanal plate. Anterior margin of adanal plate acute, with sclerotised transverse region. Each adanal plate 156 μm long, 35 μm broad; three pairs of barbed, setiform adanal setae, 54–65 μm long. One pair of minute anal setae 5 μm long.

Legs. Pre-tarsi homotridactylous; claws smooth ( Fig. 8 ). Tarsi long and thin; ratio of lengths to breadth of tarsi: I 2.69; II 2.67; III 3.02; IV 3.91. Setal formula: Leg I 1-5 -3(1)-4(1)-11(3); Leg II 1-5 -2(1)-4(1)-10(1); Leg III 2-3 -1-2(1)-10; Leg IV 1-2 -1-2-10. Most setae of tibiae, genuae and femora barbed; most tarsal setae smooth. Proral setae (p) on tarsi I-IV short, broad, blunt ( Fig. 8 a): Tarsus I with very long, broad, blunt, barbed primiventral setae (pv). Solenidion w1 separate from w1-2. Famulus (e) thin, setiform 4 μm long. Fastigial setae (ft) heteromorphic: ft ’ long, curved, smooth and pointed; ft ” large, thick, spine-like, blunt apically. Setae ft ” and ft ’ on tarsi II similarly shaped ( Fig. 8 b); those on tarsi II homeomorphic; long, curved, smooth and pointed ( Fig. 8 c). Tarsus IV with seta ft ” curved, pointed, smooth; seta s same shape and length as paired primiventral setae ( Fig. 8 d).

FIGURE 7. Tyrphonothrus maritimus sp. nov., holotype female; a) dorsal; b) ventral; c) detail of seta e 1.

Material examined. moss, Point Perpendicular, Beecroft Peninsula, New South Wales, 36°6'S, 150°48'E, coll. P. Greenslade, 21.iii.1995. Holotype deposited in the Australian National Insect Collection, CSIRO Ecosystem Sciences, Canberra.

Etymology. This species is named for the maritime location of its type locality.

Remarks. Tyrphonothrus maritimus sp. nov. differs from other members of the genus by the following combination of characters: 1) the acute rostrum; 2) the rostral setae on well-developed tubercles; 3) the lamellar setae are as longas the interlamellar setae; 4) of the prodorsal setae, the lamellar setae are barbed and the rest smooth; 5) the interlamellar setae are only three times the length of the exobothridial setae; 6) the minute foveolae on the cuticle; 7) the complex series of median and lateral longitudinal notogastral ridges; 8) the pointed caudal region; 9) the barbed notogastral and adanal setae; 10) the five pairs of genital setae with g 5 shorter than the others.

Tyrphonothrus maritimus sp. nov. shares with T. binodulus , T. fijiensis , T. gringai and T. taylori the barbed notogastral setae, five pairs of genital setae and the pattern of median, lateral and M-shaped posterior notogastral ridges. Only T. fijiensis also has the M-shaped ridge diverging medially, but differs from T. maritimus in having barbed interlamellar setae and a broad rostrum without a partial inter-rostral ridge.

Figures

FIGURE 8. Tyrphonothrus maritimus sp. nov., holotype female, left legs, antiaxial view; a) Leg I; b) Leg II; c) Leg III; d) Leg IV.