Austrocarabodes armatus, Mahunka, 2009

Mahunka, S., 2009, Oribatid Mites From The Vohimana Reserve (Madagascar) (Acari: Oribatida) I., Acta Zoologica Academiae Scientiarum Hungaricae 55 (2), pp. 89-122 : 98-100

Austrocarabodes armatus sp. n.

( Figs 15–21 )

Material examined. Holotype: Malagasy Republic, Vohimana Reserve , primary forest. 17. 04. 2008. Leg. CS . CSUZDI (Afr-996) . 1 paratype from the same sample. Holotype (1770-HO-09) and 1 paratype (1770-PO-09) in HNHM .

Diagnosis. Rostrum widely rounded. Lamellae normal, their cusps slightly rounded, dilated anteriorly bearing spiniform lamellar setae ( Fig. 21 ). Rostral setae also spiniform, directed anteriorly. Interlamellar setae large, phylliform, with 3 veins. Sensillus short, with dilated head, covered by short spines, directed laterally. Notogaster with fourteen pairs of phylliform, large setae, anterior two pairs longer than others and directed forwards. All epimeral setae simple, short. Epimeral borders and apodemes well developed, sejugal borders composing a transversal band. A pair of longitudinal ribs and border running posteriorly along the genital aperture. Anogenital setal formula 4–1–2–3. Lyrifissures iad located far from the anal aperture, well observable.

Measurements. Length of body: 373–451 µm, width of body: 208–264 µm.

Prodorsum. Rostrum rounded, lamellae slightly dilated anteriorly, with small obtuse apices. Translamella absent. Interlamellar surface covered by torn secretion layer. Some large maculae present in basal part ordered in two longitudinal rows ( Fig. 15 ). Lamellar setae spiniform, rostral setae phylliform, curved backwards, interlamellar setae ( Fig. 18 ) wide, phylliform, with two veins. Sensillus ( Figs 16–17 ) dilated distally, slightly curved backwards, distinctly barbed.

Notogaster. Anterior notogastral margin hardly convex. Humeral apophyses small, not projected forwards. Notogastral surface ornamented by large, round alveoli, in irregular position. Some of them compose a group posteromedially ( Fig.15 ). Fourteen pairs of phylliform notogastral setae present, all with one veins, their margin roughened or finely aciculate, surface also covered with same aciculae medially. Two pairs of anterior setae (c 1, c 2) directed anteriorly, one pair of them (da) longer, four posteromarginal pairs p 1 -p 3, h 3 shorter than the median ones.

Lateral part of podosoma. Lamellae with small lateral cusps. Tutorium bifurcate, one crest reaching to the lamellae. Pedotectum I large, with some foveolae.

Ventral parts ( Fig. 17 ). Apodemes and borders typical for the genus, well sclerotised and observable. Sternal region wide, with a punctate field anteriorly and a well-framed, a semicircle field in the sejugal region also punctate. Behind the epimeral borders IV a pair of well-developed longitudinal laths directed backwards, ending in a semicircle formation. Inner surface of the notogaster ornamented by large and irregular polygonal foveolae. All setae in the ventral region conspicuously thin, fine, setiform. All anal and adanal setae also fine and short. Lyrifissures iad well-observable, located far from the anal aperture.

Legs: Surface of all segments smooth. Femora of legs III with ventrodistal spur, legs IV with blade-like crest ventrally.

Remarks: The genus Austrocarabodes HAMMER, 1966 , similarly to the other genera of Carabodidae , can be divided into many species-groups. This division is difficult, however, and will most probably be performed by characteristics other than the ones used now. This idea is backed by the fact that both in the Carabodes C. L. KOCH, 1835 and Austrocarabodes genera the same characters are used for the separation of subgenera and species-groups. The significance of sculpture is not yet fully discovered, though it can fairly well characterise certain species. As very often the not fully detachable or not adequately torn secretions layer makes its study impossible.

The previously described species is well characterised by the two pairs of anteriorly directed notogastral setae (c 1, c 2), a character which also appears in the genus Carabodes (naturally here only one pair composing as a species-group.)

Among the known Austrocarabodes species three are similar to the one described here: A. agressor BALOGH et MAHUNKA, 1978 , A. erectus MAHUNKA, 1984 , and A. bellicosus P. BALOGH, 1988 . The new species is distinguishing from all three heretofore ones by the sculpture of the notogaster consisting of rare and irregularly located large foveolae and the form of the dilated sensillus. See also the key of the Austrocarabodes species of Madagascar.

Etymology. Named after the two pairs forward directed, pike-like notogastral setae.

Figures

Figs 15–21. Austrocarabodes armatus sp. n.: 15 = body in dorsal view, 16–17 = sensillus, 18 = body in ventral view, 19 = seta in, 20 = seta da, 21 = podosoma in anterodorsal view