Humerotegaeus carinatus, Colloff, 2023

Colloff, Matthew J., 2023, The oribatid mite superfamily Eutegaeoidea (Acari, Oribatida), with descriptions of new taxa from Australia and New Caledonia and a re-assessment of genera and families, Zootaxa 5365 (1), pp. 1-93 : 40-41

Humerotegaeus carinatus sp. nov.

( Fig. 18 )

Dimensions. Holotype female: length 845 μm, breadth 608 μm. Paratype female: length 909 μm, breadth 624 μm; paratype males: lengths 814 and 791 μm, breadths 569 and 553 μm. Ratio of prodorsum to total length: 0.33 (holotype).

Description of adult. Prodorsum: rostrum acute; rostral setae (ro) curved, smooth, on short tubercles, not visible in dorsal aspect. Lamellae extending slightly beyond anterolateral margin of prodorsum, lateral margins more-or-less straight; without translamella. Lamellar setae (le) smooth, almost straight, extending well beyond apices of rostral setae, emerging from small, shallow cup-shaped incisions, each flanked by short teeth; lamellar cusps not extending beyond rostrum, fused apically in midline ( Fig. 18a ). Interlamellar setae (in) same length as lamellar setae, on faint, inverted V-shaped ridge on posteromedian prodorsum. Bothridia strongly curved, projecting as far as inner margins of humeral processes, openings angled anterolaterally, posterior margin convex, lacking Vshaped anterior condyle of enantiophysis H. Bothridial setae long, curved, bacilliform, smooth, pointed.

Notogaster: ratio of length to breadth: 0.93; notogaster rounded, convex. Humeral processes with rugose microsculpture, lacking dorsal keel, slightly waisted at bases, pointed apically, extending anteriorly to point level with middle of lamella ( Fig. 18a ). With large, curved humeral plates (hp) posterolateral of humeral processes marked by indentations in margin of notogaster. With nine pairs of setae: complete l, h and p series present, marginally positioned, smooth, short (75-115 μm); l series slightly longer than h series ( Fig. 12a ).

Ventral aspect: subcapitulum acute apically; mentum as long as broad; subcapitular setae short, smooth, setae m twice as long as a and h ( Fig. 18b ). Tutorium broad, apex rounded with several short teeth. Epimeral plates broadly separated in midline, plates I triangular, with lateral ridges delineating margins of plates from pedotectum I, plates II-IV lacking median margins, plates III shorter than others with longitudinal ridge laterally with two setae medial of ridge and one lateral; epimeral setation 3-1-3-2; setae 3a and 3b longer than others. Pedotectum I (pd I) well-developed, sub-triangular, with incised region posterolaterally; pd II well developed, trapezoid, medial to and covered by large, curved humeral plates (hp) in ventral aspect; discidium with ovoid, pointed. Ventral plate broader than long. Genital and anal plates almost contiguous; perigenital carina and enantiophysis E4 present; genital plates 128 µm long, with five pairs of setae sub-equal in length, g 5 displaced laterally; lyrifissure iad in para-anal position, close to margin of anal plate. Anal plates lozenge-shaped, 213 µm long. Pre-anal organ (po) T-shaped.

Type designation, material examined and locality data. Holotype female, ANIC accession no. 53-1049; paratypes: one female, two males, ANIC accession no. 53-1050, ANIC 3751 , sieved litter and mossy logs, rainforest with Eucalyptus sp. , Lyrebird Nature Walk, 3.3 km south-east of Mount Field, Mount Field National Park , Tasmania, 42°41'S, 146°40'E, 690 m., coll. T. Weir and C. Lemann.

Etymology. The specific name, carinatus , refers to the presence of the perigenital carinae.

Diagnosis. Differences between H. carinatus and H. concentricus sp. nov. are detailed under the diagnosis for the latter species below.

Figures

FIGURE 12. Neseutegaeus wardi sp. nov., adult (a) dorsal aspect; (b) ventral aspect. Scale bar = 100 μm.

FIGURE 18. Humerotegaeus carinatus gen. et sp. nov., adult (a) dorsal aspect; (b) ventral aspect. Scale bar = 200 μm.