Constricticollis clunis Hutchinson & Allsopp, 2023

Allsopp, Peter G. & Hutchinson, Paul M., 2023, Philcarneum new genus and Constricticollis new genus, two distinctive rhinoceros beetles (Coleoptera: Scarabaeidae: Dynastinae: Pentodontini) from opposite sides of Australia with a revised key to the Australian dynastine genera, Zootaxa 5351 (3), pp. 322-340 : 330-334

Constricticollis clunis Hutchinson & Allsopp new species

( Figs. 10–20 )

urn:lsid:zoobank.org:act:9252F35A-C42F-4E0A-B0B7-92B3310D0B5C

Type material. Holotype ♀: WESTERN AUSTRALIA: Weaber Plain Rd W [estern] Aust [ralia] N of Mirima Ntl. Pk. -15.736, 128.743, S. Ong 30 Dec. [20]20 | PMH Coll # DYN 2243; in WAM.

Description of holotype female (left protarsomere 5, left metatarsomeres 3–5, right metatarsomeres 4–5 missing) ( Figs. 11–20 ). Body 15.0 mm long, 9.75 mm wide (widest across elytra post midlength); antennae dark brown with apices and margins of clubs light brown, head dark brown, pronotum brown, elytra brown with apical half dark brown; prosternum, metaventrite and abdominal sternites brown; pygidium dark brown; femora brown with distal ends black; tibiae brown with 3 teeth, carinae and apices margined black; tarsomeres brown. Mentum with postmentum wide, prementum parallel sided at base (0.4 x length), then contracted to ligula (0.3 x width of base at insertion of labial palps), ligula divergent to arcuate convex apex (0.4 x width of base), weakly convex in lateral view; ventral surface coarsely punctate along lateral margins, which bear long, brown setae. Labial palps with 3 palpomeres, with palpomere 3 as long as palpomeres 1 and 2 combined, cylindrical, widest near base then tapering to rounded apex, about 4 x as long as maximum width. Maxilla with cardo, stipes and palpifer punctate bearing long, fine, pale setae. Galea strongly toothed and sclerotised, asymmetrical; left galea with 1 intermediate tooth and 3 apical teeth (4-dentate); right galea with 1 intermediate tooth bearing 3 points and 3 apical teeth (6-dentate); lacinia undeveloped and setose. Maxillary palps with 4 palpomeres, palpomere 4 length of palpomeres 2 and 3 combined, cylindrical, parallel and widest in basal half then tapering to narrow truncated apex, length:width ratio 2.6:1, dorsally with small flat basal elliptical sensory area with micropunctures. Mandibles visible from above, apex bidentate with inner tooth narrow, external margin arcuate, outer edge with coarse setae. Antennae with 10 antennomeres; scape short, stout with apical margin bearing long, erect, brown setae; pedicel shorter than wide bearing long, erect, brown setae; antennomeres 3–7 shorter than wide, glabrous; club short, length 2.5 x width, length of shaft (antennomeres 1–7), inner face of antennomere 7 medio-longitudinally bearing dense, short setae; margins of antennomeres 8, 9 and 10 bearing sparse, erect, pale setae. Labrum sclerotised, slightly exposed in dorsal view, medially notched, mostly obscured by dense, long, yellow setae. Clypeus with narrow anterior face and broad arcuate lateral faces on same plane as clypeus, surfaces micropunctate, glabrous; anteriorly and laterally defined by distinct elevated linear ridge; disc medially and across base rugulose, laterally micropunctate bearing microsetae (30 x magnification), posterior margin gradually elevated to distinct clypeofrontal ridge that is linear, anteriorly angulate and obsolete at midpoint. Frons on same plane as clypeus, anteriorly defined by vertical elevation to clypeofrontal ridge, laterally by low elevated longitudinally linear ocular ridge making it quadrate in shape; disc with anterior half laterally coarsely rugulose bearing sparse microsetae (30 x magnification), posteriorly impunctate, glabrous. Width of frons across eyes 1.7 x interocular space at eye canthus; ocular canthi short, broad, contiguous with line of clypeolateral ridge, with ridge on lateral margin, apex broadly arcuate, disc coarsely rugulose bearing sparse microsetae (30 x magnification), apex bearing few short, yellow setae. Pronotum unarmed; highly transverse, width:length ratio 2:1; posterior margin angularly arcuate to shallow concavity medially, posterolateral angle obsolete, arcuate, laterally evenly arcuate, widest at midlength, anteriorly broadly arcuate becoming transverse to short, very obtuse (almost linear) anterolateral angle, anterior margin deeply arcuately concave; posteriorly with ridge obsolete in medial quarter (adjacent to scutellum), lateral and anterior ridges complete, anterior with membranous margin. Surface of pronotum evenly sparsely micropunctate becoming denser along anterior margin, bearing microsetae (30 x magnification). Pronotal concavity consisting of medio-longitudinal groove becoming deeper and widest at posterior margin interrupting basal convexity, middle of disc flattened and defined by paramedial anteriorly angulate well defined shallow grooves, laterally evenly and broadly rounded to margins. Scutellum wider than long, width:length ratio 1.6:1; triangular with apex arcuate, flat, impunctate and glabrous. Elytra short, width:length ratio 1:1; humeral and apical umbones low, smooth and indistinct; non-costate, disc with large deep punctures arranged in lines, lateral declivity with fine punctures becoming larger and denser apically; interstice 1 micropunctate; sutural stria linear-punctate, terminating at apex of scutellum with apices non-spinose. Lateral margins of elytra defined by a ridge; epipleura glabrous, widest basally tapering to anterior margin of metacoxae then evenly narrow to apex; distal third of elytra at suture divergent; appears as deformity due to transverse crease at base of divergence. Wings fully developed. Propygidium covered by elytra with few dispersed stridulatory ridges; bearing sparse short yellow setae across base and medially. Pygidium transverse, width:length ratio 2:1; elliptical with basal and apical margins broadly arcuate; in lateral view evenly arcuate; apical ridge widened laterally, narrow medially and glabrous; surface coarsely punctate except for small impunctate centre; bearing sparse short setae across basal half; large deep fovea in lateral angles. Mesosternum with ventral surface rugulose across anterior margin bearing sparse, short, pale setae, elsewhere impunctate and glabrous; postcoxal process obvious, columnar, apex truncate and pyriform, laterally and apically bearing long, yellow setae. Metasternum with punctures becoming larger and denser laterally bearing long, yellow setae. Abdominal ventrites 2–5 bearing single sparse row of long setae at midlength laterally, medially glabrous; sternites 6 and 7 bearing complete row pre-apically and apically respectively of sparse, long, yellow setae. Profemur with long, fine setae, sparser medially. Protibiae tridentate, denticles equidistant, long and acute; distinctly arched ventrally along length; dorsal surface bearing single medial row of stout, erect setae and sparser row basally along inner margin, inner margin anterior to spur bearing row of long, stout setae, elsewhere sparsely punctate and glabrous. Apical denticle pre-apically with distinct fovea; ventral surface bearing row of long setae at base of denticles, basally at inner margin and along inner margin anterior to spur. Spur inserted midlength of protibiae opposite longitudinal axis of second denticle; long, subparallel to rounded apex attaining midlength of protarsomere 2. Protarsomeres inserted at base of second denticle so that distal end of tarsomere 3 is level with apex of apical denticle, tarsomeres 1 and 5 of equal length and longest; all tarsomeres bearing few erect long pre-apical setae; claws simple and symmetrical. Mesofemur ventral surface in anterior half and along longitudinal ridge towards posterior margin bearing long, fine, erect setae, medially impunctate. Mesotibiae stout, widened distally 2.4 x as long as width across truncate distal margin, ventral surface and lateral margins smooth and glabrous, dorsal surface bearing 2 rows of long, erect, brown setae, inner margin quite linear, outer margin bicarinate restricted to outer half, ventral surface bearing stout, long, brown setae. Spurs long, parallel, with rounded apex, inner slightly curved and 0.8 x length outer spur, outer spur attaining apex tarsomere 2. Mesotarsomeres 1–5 combined longer than tibial length, tarsomere 1 longest with apex dilated, tarsomere 2, 3 and 5 nearly of equal length with tarsomere 4 slightly shorter; tarsomeres 1–4 bearing long, brown setae equal to length of tarsomere; claws simple and symmetrical. Metacoxae posterolateral angle arcuate through 90°, surface with sparse punctures bearing long, fine setae. Metafemora broad, length:width ratio 2:1, anterior margins arcuate, posterior margins almost straight, ventral surface with anterior margin and along longitudinal ridge towards posterior margin bearing long, fine, erect setae, medially impunctate. Metatibiae widened distally 2.0 x as long as width across truncate distal margin, ventral surface with scattered micropunctures, lateral margins bearing long, pale setae, inner margin quite linear, outer margin bicarinate with basal carina restricted to outer half and medial carina obliquely traversing tibiae bearing long, erect, brown setae. Spurs long, parallel with tapered round apices, both quite linear and inner spur 0.8 x length of outer spur; outer spur attaining apex tarsomere 3. Metatarsomeres 1–5 shorter than tibial length (based on metatarsomeres 1–3 of right leg 0.3 x length of tibiae), tarsomere 1 dilated, tarsomeres 1 and 2 bearing stout setae along length of inner margin, apical setae equal to length of tarsomere.

Male. Unknown.

Diagnostic characters. Constricticollis clunis can be recognised by the following characters. Female with clypeolateral margins elevated to same plane as clypeus, ocular canthus continuous with line of clypeus (marked by clypeolateral ridge), clypeolateral ridge linear and continued on outer margin of ocular canthus. Pronotum with posterior margin obsolete in medial third, surface with sparse micropunctures, with medio-longitudinal groove continuous from anterior to posterior margin; anterior and posterior margins incurved. Pygidium with apical ridge glabrous. Protibiae curved ventrally throughout length.

Etymology. A noun in apposition from the Latin “clunis” meaning buttocks, referring to the distinct pronotum that resembles two round human “cheeks” complete with a medial cleft. It was a name we and the collector used when referring to this unique specimen.

Distribution and habitat. Known only from the type locality near Kununurra, Kimberley Region of Western Australia ( Fig. 10 ); it has a Köppen-Geiger climate of Bsh (hot semi-arid) verging on Aw (savannah) ( Beck et al. 2018).

The specimen was captured at light on 30 December, nearing the middle of the “wet season”, in very warm, humid conditions with at least weekly rain. The locality is in grassy savanna with scattered trees at the edge of a narrow creek. The creek is very ephemeral and rocky at the bottom and in a valley between sandstone escarpments. The land where the beetle was captured is within the Wuggubun Aboriginal Community of the Gija people.

Figures

FIGURE 10. Known distribution of Philcarneum aenigma Allsopp & Hutchinson new genus, new species in southern New South Wales (blue dots) and of Constricticollis clunis Hutchinson & Allsopp new genus, new species in northwestern Australia (red dot).

FIGURES 11–14. Constricticollis clunis Hutchinson & Allsopp new genus, new species, holotype female: 11, dorsal view; 12, ventral view; 13, lateral view; 14, labels.

FIGURES 15–20. Constricticollis clunis Hutchinson &Allsopp new genus, new species, holotype female: 15, frontal view; 16, rear view; 17, head, dorsal view; 18, head, ventral view; 19, head, dorso-lateral view; 20, head and pronotum, dorsal view.