Austrocarabodes longisetosus, Hugo-Coetzee, Elizabeth A., 2011

Hugo-Coetzee, Elizabeth A., 2011, Three new species of Austrocarabodes (Oribatida: Carabodidae) and notes on Austrocarabodes pinnatus Mahunka, 1986, from South Africa, Zootaxa 3011, pp. 1-15 : 6-8

Austrocarabodes longisetosus sp. nov.

( Figs 5 , 6 )

Colour. Light brown to yellow

Dimensions. Length: females (n = 6) mean 638 μm (range 590–710), males (n = 5) mean 664 μm (range 570– 740). Width: females mean 415 μm (range 380–450), males mean 406 μm (range 330–470). Holotype (male): length 740 μm, width 470 μm.

Prodorsum ( Fig. 5 A). Surface of lamella smooth, prodorsal surface between lamellae with foveolae arranged in rows; rostrum rounded; ro, le, in very long, phylliform, barbed, ending in sharp tips, with strong midribs, ro inserted on tubercle originating on translamella, curving laterally, then inward, tips of le almost touching, in very long (220 μm), almost as long as lamella, curving upwards, outwards and downwards; sensillus with short peduncle, head long, clavate, weakly curving backward, with strong barbs, barbs inconspicuous on posterior side.

Notogaster ( Fig. 5 A). Surface with small foveolae arranged in polygonate pattern, anterior margin convex with irregular edge; notogastral setae long (mean across 14 pairs = 180 μm), narrowly phylliform, tips pointed, serrated, with strong midribs, c1, dm reaching the alveolus of da, dp respectively; c1 and c2 not always directed forward as in holotype, in paratypes curving laterally and backwards.

Coxisternal region ( Fig. 5 B). Surface lightly punctate (punctate in holotype, but in two specimens from near the Tugela River and Mapelane similar ornamentation than the anogenital region); mentum posteriorly with halfcircle formation; apodemes and borders clearly visible; apodeme 4 thick with lighter band in middle; 1a, 1c, 2a, 3a short, spiniform, smooth, 1b, 3b, 4a, 4b longer, smooth, 3c, 4c long, barbed.

Anogenital region ( Fig. 5 B). Surface with foveolae arranged in rows, foveolae larger in the middle, decreasing in size towards the anterior and posterior regions, punctate next to genital and anal plates; distinct ridge between the genital and anal plates, surface posterior of ridge punctate; genital setae smooth, short, ag setae long, smooth, anal setae short, smooth, ad setae phylliform, similar to notogastral setae but smaller, shorter; lyrifissure iad situated posterio-laterally of ad3, closer to ad3 than to lateral margin of ventral plate.

Legs ( Fig. 6 ). Legs similar to legs of A. nortoni except on average across 4 pairs of legs ± 20 μm shorter; solenidion ω2 (14 μm) on leg I much shorter than ω1 (35 μm); paraxial and antiaxial surface of Fe, Tr finely punctate (see Table 1 for setation detail).

Etymology. The species name is derived from the long dorsal setae (longus —long; seta —hair).

Differential diagnosis and remarks. The combination of the very long, barbed dorsal setae, the ornamentation on the notogaster and prodorsum, the form of the sensillus (head long, clavate, bending slightly backward) and the distinct ridge between the genital and anal plates on the ventral side make this species unique.

The above-mentioned characteristics have been observed in other Austrocarabodes species, although not in combination as is seen in A. longisetosus . Austrocarabodes curvisetiger Aoki, 1982 , A. elegans Hammer, 1966 , A. bacilliger and A. patakii all have very long dorsal setae. However, the setae of A. curvisetiger are wider with the tips of the setae long and bent. Austrocarabodes elegans have narrower setae with the tips long and bent. Austrocarabodes bacilliger has smooth, bacilliform dorsal setae and the setae of A. patakii are nearly baciliform with small barbs and without midribs. Furthermore, A. haradai has a similar clavate sensillus which also weakly curves backwards. Austrocarabodes fenestratus ( Wallwork, 1977) , A. lunaris ( Balogh, 1962) , A. nodosus Hammer, 1966 and A. sinuosociliatus have an arched chitinous ridge between the genital and anal plates.

Type material. The holotype (1807.3.1) was sampled in the Royal Natal National Park (28º39’S, 29º03’E) in KwaZulu-Natal in soil and plant debris underneath Leucosidea sericea by C. M. Engelbrecht, 26.i.1982. Two paratypes (2410.9) are from Nelspruit district (25º31’S, 31º02’E) in Mpumalanga, sampled from dry, loamy soil with decomposed plant debris collected by C. M. Engelbrecht, 9.ii.1982; one paratype (1927.22) is from near the Tugela River between Stanger and Gingingluvu (29º10’S, 31º25’E) in KwaZulu-Natal from relatively dry soil and decomposed plant debris collected by C. M. Engelbrecht, 2.viii.1982. The holotype and paratypes are deposited in the Acarology collection of the National Museum, Bloemfontein, South Africa.

Collection data. Known distribution of A. longisetosus is indicated by filled triangles on the map of South Africa, Fig. 4 . Abbreviations for provinces: KZN = KwaZulu-Natal; MP = Mpumalanga.

Montrose MP (25º27’S, 30º42’E, dry, red, loamy soil with decomposed leaf litter under indigenous trees); Sabie MP (25º06’S, 30º46’E, humid soil in dense forest); Mapelane KZN (28º25’S, 32º20’E, inland of dunes, natural vegetation); Cape Vidal State Forest KZN (28º07’S, 32º33’E, indigenous forest).

Figures

FIGURE 4. Known localities of Austrocarabodes nortoni sp. nov. (filled squares), A. longisetosus sp. nov. (filled triangles), A. crassimarginatus sp. nov. (filled circles) and A. pinnatus Mahunka, 1986 (filled stars) in South Africa.

FIGURE 5. Austrocarabodes longisetosus sp. nov. holotype male, A. Dorsal view (100 μm). Magnifications of sensillus (ss) and notogastral seta dm (50 μm); B: ventral view (100 μm).

FIGURE 6. Austrocarabodes longisetosus sp. nov. Leg I, left, antiaxial view.