Scapheremaeus allmani, Colloff, Matthew J., 2010

Colloff, Matthew J., 2010, The hyperdiverse oribatid mite genus Scapheremaeus (Acari: Oribatida: Cymbaeremaeidae) in Australia, with descriptions of new species and consideration of biogeographical affinities, Zootaxa 2475, pp. 1-38 : 5-8

Scapheremaeus allmani sp. nov.

(Fig. 2, 4)

Dimensions. Holotype female: length 490, breadth 295; paratype females (n = 6): length 539 (range 515– 566), breadth 313 (range 288–333). Paratype male: length 456, breadth 273. Ratio of length of prodorsum to total length (holotype): 0.23.

FIGURE 2. Scapheremaeus allmani sp. nov. a) dorsal; b) ventral; c) lateral; d) detail of lamellar seta and apophysis; e) detail of sensillus; f) detail of setae h 2 (left) and p 2 (right).

Prodorsum. Rostrum acute, with faint transverse striae; rostral seta long (31), curved, setiform (Fig. 2a). Lamellar seta 17, bacilliform, covered in cerotegument (Fig. 2d). Apophyses of lamellar seta 40 long, extending beyond rostrum, expanded basally, converging apically. Costulae curving medially from anterior of bothridia, becoming parallel; with anterior, medial and posterior trans-costular ridges, the posterior ones in the form of a diagonal cross. With well-developed lateral carinae, more or less parallel to costulae; prodorsum with faint longitudinal striae lateral of carinae. Interlamellar seta absent. Bothridium with broad rim; sensillus club-shaped, stalk 17 long, head dark, 30 long 16 broad, with striae and minute spines (Fig. 2e).

Notogaster. Length 370. Circumdorsal scissure entire, with diagonal extensions into humeral region (Fig. 2a). Lenticulus sub-circular with thick rim (diameter 30); U-shaped depressions lateral of lenticulus. Long, curved humeral process extending laterally and anteriorly from margin of circumnotogastral plate. Centrodorsal region 288 long, 195 broad, rounded posteriorly, with microsculpture consisting of round or polygonal tubercles, bisected by a raised centrodorsal region with microsculpture consisting of transverse ridges. Ten pairs of smooth, bacilliform notogastral setae with club-shaped cerotegument darkened apically (Fig. 2f); setae on short tubercles. Centrodorsal plate pear-shaped, broadest at lyrifissures ih; with two pairs of setae, lm and lp, positioned laterally; gla anteriolateral of lp. Dorsal circumnotogastral plate sparingly plicate; with five pairs of setae: c 2 (18) in lateral humeral depression, la posteriolateral to c 2; h series positioned on rounded caudal region; ventral circumnotogastral plate with three pairs of setae in p series, not visible in dorsal view.

Ventral region. Epimeral setae setiform, formula 3-1-2-2, setae 1c 23, at least twice as long as 1a and 1b; setae 4a 25, twice as long as 4b. Sub-hexagonal genital plates with six pairs of longitudinally-aligned genital setae positioned close to, but not on, medial edges of plates; each genital plate with elongated plaques, similar to those of anal plates; setae g 1 27, at least twice as long as g 2-6. Posterior part of ventral plate with ridged microsculpture radiating laterally from peri-anogenital region. Anal setae 14, positioned at least their length from median edge of anal plates. Seta ad 3 18, longer than other adanal setae, positioned at least its length from the lateral margin of the anal plates; ad 1 and ad 2 positioned posterior of anal plates and adjacent to them. Ventral surface of circumnotogastral plate notched posteriomedially, bearing short, spinose setae of p series, some with clavate cerotegument, others without.

Lateral aspect. Mid-line of rostrum slightly slanted posterioventrally; lamellar apophyses separated from prodorsum for a third of the distance between bothridia and bases of setae le. Exobothridial seta absent. Humeral process 57 long, straight, spiniform, directed anterioventrally, with smaller pair of spines positioned posteriorly and separated from rectangular plate-like extension by deep notch. Lenticulus projecting 12 above dorsum; with centrodorsal ridge extending from just posterior from setae la to as far as lp, extending dorsally 40 above lateral margin of circumdorsal scissure, sloping to caudal margin of scissure.

Legs. Heterotridactylous; covered in thick cerotegument consisting of irregular plaques; porose areas on trochantera and femora. Seta l " on tibia I thick, straight, strongly barbed, club-shaped apically ( Fig. 4 b). Solenidion φ2 on tibia I emerging from apophysis positioned on dorsal surface of apophysis of φ1. Formula Leg I: 1-4-2(1)-4(2)-14(2); Leg II: 1-3-2(1)-4(1)-14(1); Leg III: 1-2-1(1)-4(1)-13; Leg IV: 1-2-1(1)-3(1)-10.

Material examined. Holotype female, two paratype females and one paratype male, on galled twig of Ficus sp., Lismore, New South Wales, coll. S.L.A. [Stuart Leo Allman], 12.vi.1934 (ex. Biological and Chemical Research Institute, New South Wales Department of Agriculture, Rydalmere, New South Wales). One paratype female on bark of eucalypt, Sydney, New South Wales, coll. [S.L. Allman], 16.vii.1934. Two paratype females on Apiomorpha sp. gall on eucalypt, Boomi, New South Wales, [coll. S.L. Allman], 16.viii.1934. One paratype female ex. Casuarina sp., 25 km west of Mt. Glorious, Queensland, coll. D.E. Walter, 4.x.1999. Holotype and paratypes in the Agricultural Scientific Collection, New South Wales Department of Primary Industries, Orange. Paratype from Queensland in ANIC.

Etymology. This species is named in honour of the late Stuart Allman, Chief Entomologist, New South Wales Department of Agriculture, who collected it.

Remarks. Scapheremaeus allmani sp. nov. can be separated from other members of the genus by the following combination of characters: 1) tuberculate centrodorsal microsculpture with transverse centrodorsal ridges; 2) long, curved lamellar apophyses with bacilliform lamellar setae; 3) extremely long, straight humeral processes with posterior complex of small pair of spines, a notch and rectangular plate; 4) anterior, median and posterior transcostulae; 5) epimeral setal formula 3-1-1-2; 6); head of sensillus with small spines. The epimeral setal formula of 3-1-1-2 is shared only with S. tegulatus sp. nov. (cf. below).

Scapheremaeus allmani sp. nov. is a member of the Carinatus species-group ( Colloff, 2009), and part of a sub-group with long lamellar apophyses, setae lm and lp on the lateral margin of the centrodorsal shield and setae of the p series on the ventral surface of the circumnotogastral plate. The sub-group includes S. bicornutus Hammer, 1971 ( Fiji) ; S. fisheri Aoki, 1966 (Hawaii) ; S. insularis Hammer, 1966 ( New Zealand) and S. semiconvexus Hammer, 1982 (Bali) , as well as S. tegulatus sp. nov.

Figures

FIGURE 4. a) Scapheremaeus baylyi sp. nov., circumnotogastral plates, viewed ventrally (centrodorsal plate removed); b – e) tibiae I (right, antiaxial); b) Scapheremaeus allmani sp. nov., showing cerotegument; c) Scapheremaeus tuberculosus sp. nov.; d) Scapheremaeus alisonae sp. nov.; e) Scapheremaeus bulbosensillatus sp. nov.