Scapheremaeus pulleni, 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 : 16-19

Scapheremaeus pulleni sp. nov.

( Figs. 6 , 7 )

Dimensions: Length: holotype: 430; paratype: 455. Breadth: holotype: 242; paratype: 268.

Integument. Cerotegument consisting of fine dark nodules. All surfaces of the body with ornate microsculpture

Prodorsum. Tuberculate laterally with pattern of diagonal ridges medially between costulae. Rostrum pointed, rostral setae (ro) smooth, curved, ca. 13 long; lamellar setae (le; ca. 5 long) as long as the tubercles from which they emerge; translamella present. Costulae well developed, more-or-less parallel, extending posteriorly as far as bothridia. Interlamellar setae absent. Sensillus club-shaped, darkly-pigmented, head ca. 12 broad, with tuberculate microsculpture, apex barely extending beyond prodorsal margin.

Notogaster. Length 323. Circumdorsal scissure entire, with diagonal extensions into humeral region. Lenticulus present (ca. 35 long, 26 broad), flanked by tuberculate protuberances. Centrodorsal region 253 long, 177 broad; with microsculpture consisting of linearly-arranged elongate plaques. Microsculpture of region lateral of circumdorsal scissure consisting of parallel ridges and troughs posteriorly and scattered tubercles anteriorly. Ten pairs of smooth, minute (ca. 5–7 long) spiniform notogastral setae; those of h and ps series borne on short tubercles; lm and lp positioned on centrodorsal region. Caudal region convex. Lyrifissurae ih, ips and ip present on posterior half of laterodorsal region; ih and ips parallel, oblique.

Lateral aspect. Microsculpture composed of round, oval and elongate tubercules arranged in linear patterns. Costulae projecting above surface of prodorsum, but tubercle of lamellar setae not free. Tutorium consisting of angular ridge ventral of lamella; cusp or free projection absent. Pedotectum I auriculate, covering acetabulum I; pedoctectum II bladelike, positioned slightly posterior of acetabula II. Humeral spine short, broad, with two blunted apices.

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 similar to that of lateral region. Lyrifissurae iad in para-anal position.

Gnathosoma . Typical of family. Tectum of mentum slight, not extending anteriorly as far as bases of setae a.

Legs. Setal formulae: legs I: 1-3-2(1)-4(2)-14(2); legs II: 1-3-2(1)-2(1)-13(1); legs III: 1-2-1(1)-3(1)-12; legs IV: 1-2-1(1)-3(1)-12. Lengths of leg segments (femur to tarsus): legs I: 86, 28, 58, 26; legs II: 83, 22, 51, 22; legs III: 70, 19, 55, 24; legs IV: 68, 23, 51, 31. 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 and paratype: pitfall trap, Mallee eucalypt vegetation on dune-swale system, 14 km WNW Renmark, 34°07’S 140°37’E, South Australia; coll. K. Pullen, 2 May–7 June, 1995. Types in ANIC.

Etymology. This species is named after its collector, Kimberi R. Pullen (CSIRO Entomology) in recognition of his contribution to Australian entomology.

Remarks. Scapheremaeus pulleni sp. nov. can be distinguished from other members of the genus by the following combination of characters: 1) the linear arrangement of elongated plaques on the centrodorsal region; 2) a complete circumdorsal scissure with humeral extensions; 3) 10 pairs of setiform notogastral setae, those of the p series on dorsal circumnotogastral plate; 4) a diagonal cross-shaped posterior transcostular ridge; 5) prodorsal microsculpture tuberculate; 6) humeral process short, sub-triangular, notched apically.

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 6. Scapheremaeus pulleni sp. nov. a): dorsal aspect; b) ventral aspect; c) lateral aspect.

FIGURE 7. Scapheremaeus pulleni sp. nov.; right legs, paraxial view: a) leg I; b) leg II; c) leg III; d) leg IV.