Scapheremaeus angusi, Colloff, Matthew J., 2009

Colloff, Matthew J., 2009, Comparative morphology and species-groups of the oribatid mite genus Scapheremaeus (Acari: Oribatida: Cymbaeremaeidae), with new species from South Australia, Zootaxa 2213, pp. 1-46 : 19-21

Scapheremaeus angusi sp. nov.

( Figs. 8–10 )

Dimensions: Length: holotype: 531; paratypes (mean and range; n = 7): 623 (545–678). Breadth: holotype: 343; paratypes (mean and range; n = 7): 368 (308–418).

Integument. Dark, granular cerotegument present. All surfaces of body with ornate microsculpture

Prodorsum. Tuberculate laterally, with rugose pattern of poorly defined ridges medially between costulae. Rostrum pointed, rostral setae (ro) smooth, pointed, ca. 11 long; lamellar setae (le; ca. 13 long) with clubshaped tips of cerotegument, on small tubercles (ca. 8 long) slightly longer than broad, connected by translamela. Costulae well developed, more-or-less parallel, extending posteriorly as far as bothridia. Alveoli of interlamellar setae (in) present. Sensillus club-shaped, darkly-pigmented, tuberculate, head ca. 19 broad, apex extending well beyond prodorsal margin; stalk ca 25 long.

Notogaster. Length 450. Circumdorsal scissure entire, with diagonal extensions into humeral region. Lenticulus present (ca. 41 long, 38 broad) flanked by tuberculate protuberances. Centrodorsal region 348 long, 233 broad; with microsculpture consisting of randomly-arranged minute foveolae. Anterior two thirds of centrodorsal region strongly ridged. Microsculpture of region lateral of circumdorsal scissure consisting of parallel ridges and troughs. Ten pairs of smooth, short (8–14 long) spiniform notogastral setae borne on short tubercles; lm and lp positioned on centrodorsal region. Caudal region indented slightly. Lyrifissurae ih, ips and ip arranged radially on posterior half of laterodorsal region.

Lateral aspect. Prodorsal microsculpture composed of round, oval and elongate tubercles arranged in linear patterns. Costulae projecting markedly above surface of prodorsum; tubercle of lamellar seta free of prodorsal surface. Carina an angular ridge ventral of lamella; cusp or free projection absent. Pedotectum I auriculate, covering acetabulum I; pedoctectum II narrow, bladelike, midway between acetabula II and III, apex directly ventral of short humeral spine.

Ventral region. Epimeral setal formula, numbers of aggenital, anal and adanal setae typical of genus; 6 pairs of genital setae; g 2 offset laterally from g 1. Ventral microsculpture consisting of series of ridges and plaques. Lyrifissurae iad in para-anal position.

Subcapitulum. Mentum with ridged microsculpture; tectum of mentum slight, not extending anteriorly as far as bases of setae a. Setal formula of palp: 1-1-3-9(1); tarsal formula including 4 eupathidia. Tarsus with prominent tubercle bearing eupathidium acm; eupathidium not attached to solenidion.

Legs. Setal formulae: legs I: 1-4-2(1)-4(2)-14(2); legs II: 1-3-2(1)-3(1)-13(1); legs III: 1-2-1(1)-3(1)-12; legs IV: 1-2-1(1)-3(1)-11. Lengths of leg segments: legs I: 110, 38, 70, 32; legs II: 116, 44, 90, 40; legs III: 86, 30, 76, 38; legs IV: 80, 36, 82, 46. Femora I-IV with tuberculate microsculpture on antiaxial surface and series of parallel ridges on paraxial surface; circular porose areas present on paraxial surfaces. Claws heterotridactylous.

Material examined: Holotype: pitfall trap, Casuarina woodland, 79 km NNW Renmark, 33°31’S 140°24’E; coll. A. Lambie, 3 May - 6 June, 1995. Paratypes: 1 adult, as above, coll. K. Pullen, 29 March–3 May, 1995. 1 adult, gutter of flight intercept trap, Mallee eucalypt vegetation on dune-swale system, 14 km WNW Renmark, 34°.07’ S 140°37’ E; coll. K. Pullen, 13 Dec, 1995–25 Jan, 1996. 1 adult, gutter of flight intercept trap, Mallee eucalypt vegetation on dune-swale system, 14 km WNW Renmark, 34°.07’ S 140°37’; coll. K. Pullen, 13 Dec, 1995–25 Jan, 1996. 3 adults, data as above, 28 February –28 March, 1995. 1 adult, gutter of flight intercept trap, Mallee eucalypt vegetation on dune-swale system, 31 km NW Renmark, 33°59’ S 140°30’; coll. K. Pullen, 30 March - 2nd May, 1995. 1 adult, malaise trap, Mallee eucalypt vegetation on dune-swale system, 32 km NW Renmark, 33°59’ S 140°30’; coll. K. Pullen, 11 October–9 November, 1995. Types in ANIC.

Etymology. This species is named after my youngest son, Angus John Colloff.

Remarks. Scapheremaeus angusi sp. nov. can be distinguished from other members of the genus by the following combination of characters: 1) the minutely foveolate centrodorsal region; 2) a complete circumdorsal scissure with humeral extensions; 3) the massive centrodorsal ridge and posterior concave region; 4) the rugose inter-costular microsculpture; 5) short, sub-triangular humeral processes; 6) 10 pairs of setiform notogastral setae, those of the p series on dorsal circumnotogastral plate; 6) with palp setal formula 0- 1-1-3-9; missing femoral seta l ".

This species is most similar morphologically to S. cheloniella but differs in the pattern of the centrodorsal microsculpture, and the shape of the posterior transcostular ridge and humeral process.

Figures

FIGURE 8. Scapheremaeus angusi sp. nov. a) dorsal aspect; b) ventral aspect; c) lateral aspect.