Malaconothrus gundungurra, 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 : 324-327

Malaconothrus gundungurra sp. nov.

( Figs. 13 c, 13d, 15, 16)

Dimensions. Holotype female length 441 μm, breadth 202 μm. Paratype females: mean length (n = 10) 431 μm (range 394–460 μm), mean breadth 192 μm (range 183–211 μm). Ratio of prodorsum to total length: 0.35 (holotype).

Female. Prodorsum. Rostrum broad, curved ( Fig. 15 a). Rostral seta (ro) smooth, thin, recurved, 35 μm long, shorter than mutual distance, on apex of lateral carina. Lamellar seta (le) smooth, setiform, 26 μm long, shorter than ro and mutual distance, on flat tubercles just medial of lateral carina. Interlamellar seta (in) smooth, flagelliform apically, 74 μm long, 3 × length of exobothridial seta. Prodorsum finely porose, with granular cerotegument. Well-developed posterior interlamellar ridge.

Notogaster. Dorsosejugal furrow slightly convex; humeral region rounded ( Fig. 15 a). With 15 pairs of curved, setiform, smooth setae, plus f 1 represented by their alveoli. Lateral setae mostly sub-equal in length (26–34 μm), overlapping; medial setae c 1, d 1, and e 1 longer than others (38–49 μm). With narrow lateral ridges on which are positioned setae c 2 and d 2. With curved indentation between seta h 1 and anteriomedial of p 1. Seta h 1 19 μm long, by far the shortest of the notogastral setae. Notogastral margins more-or-less parallel, broadest at level of c 3. Ratio of length to breadth 1.46. Caudal margin very slightly indented at level of h 2, otherwise U-shaped. With short concave ridges between h 3 and p 2 and between p 2 and posterior margin of notogaster. Lyrifissurae ip obtuse. Notogaster densely porose.

Subcapitulum. Palp setal formula (solenidion in brackets) 0-1-3-9(1); palp tarsus short, rounded apically; eupathidial setae spiniform, pointed; solenidion ω curved, bacilliform. Seta d on tibia strongly barbed, 21 μm long ( Fig. 13 c). Cheliceral seta cha short, spiniform, smooth; Pb curved, flat, barbed on one edge ( Fig. 13 d).

Coxisternum. Epimeral setal formula 3-1-3-3 ( Fig. 15 b). Setae on epimeres I and II very short, setiform, smooth. Setae 3b, 3c, 4a and 4c longer than others (16–26 μm long); 1c in posteriolateral position; 3 b mediolateral; 4b lateral. Epimeral plates separated medially except II which is fused posteriorly and III which is fused anteriorly. Epimeral plates I with well-developed spur anteriolaterally. Epimeral plates II acute posteriolaterally. Epimeres III and IV of equal width, without paired lateral spines. Apodeme IV, as far as posteriolateral acetabulum, strongly concave.

Anogenital Region. With four pairs of smooth, curved, setiform genital setae subequal in length (19–27 μm), g 1-3 closely spaced; g 4 directed posteriorly, at least twice distance from g 3 as from g 3 to g 2; setae shorter than width of genital plate. Each genital plate 86 μm long, 44 μm broad, semi-circular. One pair of anal setae 21 μm long, twice width of anal plate. Each adanal plate 81 μm long, 25 μm broad; three pairs of smooth, setiform adanal setae, 30–39 μm long, longer than width of adanal plate. Anterior margin of adanal plate overlapped by posterior margin of genital plate.

Legs. Pre-tarsi monodactylous; claw smooth ( Fig. 16 ). Legs short and broad: Leg I 125 μm long. Tarsi I squat, sub-conical: ratio of lengths to breadths of tarsi: I 1.93; II 1.86; III 2.6; IV 3.45. Setal formula: Leg I 1-5 -4(1)-4(1)- 11(3); Leg II 1-6 -3(1)-4(1)-10(1); Leg III 2-3 -2-2(1)-10; Leg IV 0- 2 -2-2-10. All setae on all segments smooth. Tarsus I with proral setae (p) short, broad basally, flagelliform apically ( Fig. 16 a): short, blunt and spindle-shaped on other tarsi; unguinal setae (u) short, blunt and broad: peg-like; solenidia (ω1-3) clustered; famulus (ε) spiniform, short (4 μm). Tarsus I and II with fastigial setae (ft) heteromorphic: ft ” smooth, curved, long, pointed, ft ’ short, blunt and broad ( Figs. 16 a, b). Tarsus III with fastigial setae homeomorphic: smooth, curved, long, pointed ( Fig. 16 c). Tarsus IV with ft ” long (43 μm), curved, pointed; seta s same shape and length as primiventral setae (pv) ( Fig. 16 d).

Material examined. Holotype female and 15 paratype females, soaking wet liverworts, Leura Cascades Walk, near Leura, Blue Mountains, New South Wales, 33°43'17"S 150°19'21"E, 880 m., coll. M.J. Colloff, 17.i.2011. Thirty paratype females, soaking wet moss and liverwort, west of Weeping Rock, Wentworth Falls, Blue Mountains, New South Wales, 33°43'36"S 150°22'14"E, 830 m., coll. M.J. Colloff, 14.i.2011. Holotype and paratypes deposited in the Australian National Insect Collection, CSIRO Ecosystem Sciences, Canberra.

Etymology. This species is named for the Gundungurra People of the Blue Mountains of New South Wales on whose ancestral land this species was found.

Remarks. Malaconothrus gundungurra sp. nov. differs from other members of the genus by the following combination of characters: 1) the lamellar setae shorter than the rostral setae; 2) medial setae c 1, d 1, and e 1 longer than other notogastral setae; 3) setae f 1 present, represented by their alveoli; 4) with curved indentation between seta h 1 and anteriomedial of p 1; 5) the very short setae h 1; 6) the four pairs of genital setae, with g 4 separated from the others and pointing posteriorly; 7) the long anal setae; 8) the adanal setae as long or longer than setae p 2-3.

Malaconothrus gundungurra sp. nov. is one of a group of species that share the following character states: a U-shaped caudal margin, four or five pairs of genital setae with the most posterior ones pointing posteriorly; with the median notogastral setae longer than the lateral setae and with the lamellar setae about the same length or shorter than the rostral setae. The group includes M. hammerae nom. nov. (= M. angulatus Hammer, 1958 ; cf. ‘Nomenclatorial Considerations’ above); M. mollisetosus Hammer, 1958 ; M. minutus Fujikawa, 2005 ; M. setoumi Fujikawa, 2005 , M. monodactylus ( Michael, 1888) and M. zealandicus Hammer, 1966 . Malaconothrus monodactylus has interlamellar setae only slightly longer than the exobothridial setae; M. setoumi and M. minutus have five pairs of genital setae, M. zealandicus has faint longitudinal notogastral ridges and M. hammerae has much shorter setae in and setae c 2-3, as well as much longer setae e 2 and h 1. Malaconothrus gundungurra is morphologically most similar to M. mollisetosus but has much shorter setae h 1 and well-developed curved indentations between seta h 1 and anteriomedial of p 1.

Figures

FIGURE 13. Malaconothrus darwini sp. nov., paratype female; a) subcapitulum; b) chelicera; Malaconothrus gundungurra sp. nov. paratype female; c) palp; d) chelicera.

FIGURE 15. Malaconothrus gundungurra sp. nov., holotype female; a) dorsal; b) ventral.

FIGURE 16. Malaconothrus gundungurra sp. nov., holotype female, left legs, antiaxial view; a) Leg I; b) Leg II; c) Leg III; d) Leg IV.