Scapheremaeus tegulatus, 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 : 22-24

Scapheremaeus tegulatus sp. nov.

( Fig. 11 )

Dimensions. Holotype female: length 375, breadth 205; paratype female: length 337, breadth 195. Ratio of length of prodorsum to total length (holotype): 0.25.

Prodorsum. Rostrum acute, with faint polygonal plaques; with short (10), straight, setiform rostral setae ( Fig. 11 a). Lamellar setae minute (8), curved, bacilliform. Apophyses of lamellar setae 28 long, extending beyond rostrum, expanded basally, converging apically. With anterior, medial and posterior transcostular ridges; costulae curving medially from anterior of bothridia, waisted at medial transcostular ridge. With welldeveloped carinae, expanded laterally. Prodorsum with polygonal depressions. Bothridium with broad rim; sensillus club-shaped, stalk 16 long, head 20 long 14 broad, smooth, dark.

Notogaster. Length 280. Circumdorsal scissure entire, oval, without diagonal extensions into humeral region ( Fig. 11 a). Lenticulus 22 long, 15 broad, wedge-shaped with discrete margin. Circumnotogastral plate without U-shaped depressions lateral of lenticulus, broadest at level of setae lm. Humeral processes present but not clearly visible in dorsal view (cf. lateral aspect, below). Centrodorsal region with microsculpture consisting of polygonal alveolate depressions, 225 long, 130 broad, rounded posteriorly, with a raised centrodorsal region and posteriolateral concavities. Fourteen pairs of smooth, notogastral setae on short tubercles; anterior setae spiniform, posterior setae bacilliform. Five pairs of setae on centrodorsal plate; lm and lp positioned laterally, da, dm and dp positioned either side of centrodorsal ridge. Circumnotogastral plate plicate, with polygonal depressions anteriorly, bearing six pairs of setae: c 1 immediately lateral of lenticulus, c 2 (18) on humeral region, la some distance posteriolateral to c 2; h series positioned on rounded caudal region; setae of p series not visible from above.

Ventral region. Epimeral setae setiform, subequal in length, formula 3-1-2-2 ( Fig. 11 b). Genital plates sub-rectangular, alveolate, surrounded by irregular ridges; with five pairs of genital setae; g 1 positioned lateral of g 2-6. Ventral plate alveolate. Anal setae 7, positioned at least their length from median edge of alveolate anal plates. Adanal setae minute, subequal in length (ca. 6); ad 1-2 positioned on ridge immediately posterior of anal plates; ad 3 positioned at least twice their length from the lateral margin of the anal plates. Circumgastric scissure notched medially. Ventral surface of circumnotogastral plate bearing three pairs of short (ca. 7), spinose setae of p series.

Lateral aspect. Mid-line of rostrum vertical or slightly bowed posterioventrally; lamellar apophyses separated from prodorsum for a third of the distance between bothridia and bases of setae le ( Fig. 11 c). Humeral process elongated, lath-like, rounded distally, ca. 80 long, 12 broad. Lenticulus projecting above dorsum; with centrodorsal ridge extending from just anterior of seta da to posterior of lp, extending 30 above circumdorsal scissure, sloping to caudal margin of scissure.

Legs. Heterotridactylous.

Material Examined. Holotype female and paratype female, from pyrethrin knock-down, Mt. Victoria, Tasmania, coll. H. Mitchell and R. Coy, 25.xi.1989: same sample and data as for S. euthemellus sp. nov. (cf. above).

Etymology. The specific name tegulatus is Latin for ‘tiled’ and refers to the pattern of the polygonate alveolate centrodorsal microsculpture.

Remarks. Scapheremaeus tegulatus sp. nov. can be separated from other members of the genus by the following combination of characters: 1) fourteen pairs of notogastral setae; 2) massive elongated lobe-shaped humeral process; 3) five pairs of genital setae; 4) long, curved lamellar apophyses with bacilliform lamellar setae and anterior, median and posterior transcostular ridges; 5) smooth sensillus; 6) ventral circumnotogastral plate with a median post-anal slit, and 7) extensive microsculpture of large alveoli on dorsal and ventral surfaces.

Scapheremaeus tegulatus sp. nov. is a member of the Patella species-group. It has most character states in common with S. hammerae Balogh & Balogh, 2002 from New Zealand, but no other members of the group have elongated lamellar apophyses, long humeral processes, the centrodorsal microsculpture consisting of polygonate depressions or five pairs of genital setae.

Figures

FIGURE 11. Scapheremaeus tegulatus sp. nov. a) dorsal; b) ventral; c) lateral.