Philcarneum aenigma Allsopp & Hutchinson, 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 : 325-327

Philcarneum aenigma Allsopp & Hutchinson , new species

( Figs. 1–10 ; Allsopp & Hutchinson 2019 fig. 13) urn:lsid:zoobank.org:act:A87A646B-666F-45BF-96E7-C5020AB9CA0C

Type material. Holotype ♀: NEW SOUTH WALES: Moruya NSW 24 Mar. 1968 K. Pullen; in ANIC.

Paratypes. NEW SOUTH WALES: 1♀ [abdomen missing]: Mouthparts dissected out and on card | Tuross Beach, N.S.W. 10 mi. [miles] S. of Moruya 26.i.1969. S. Misko | vidit 1978 R.-P. Dechambre | [Camera icon] ANIC Image; in ANIC. 1♀: N. S. Wales. Bega (Edwards) 9-III-1905 | gen. et sp. nov. near Calicnemis Cast. P.B. Carne det. 1980 | Calicnemis sp. nr. latreillei Cast. P.B. Carne det 1979 | NSW Agriculture ASCT00091953; in NSWDPI.

Description of holotype female (mouthparts from paratype female) ( Figs. 1–9 ). Body 13 mm long; antennae yellow-brown, labrum, clypeus and sculptured part of frons dark brown, smooth part of frons brown, clypeofrontal suture black, disc of pronotum largely brown but dark brown anterior to anterior ridge and very dark brown to black patches laterally about mid length, scutellum brown with lateral edges and apex dark brown to black, elytra brown with inner margins black, pygidium brown, venter brown except apex of last abdominal ventrite yellow-brown, legs brown except apex of protibia, metafemur and metatibia dark brown to black. Mentum with postmentum short and tapering to narrow lateral margins; prementum expanded from base to about one-third length then contracted towards ligula, maximum width 1.4 x basal width, ligula basal width 0.85 x prementum basal width, ligula margin concave forming two shallow lobes and depressed below level of remaining mentum, surface roughened and with scattered long, brown setae; labial palps with palpomere 3 swollen to about half length then contracted to narrow, rounded apex, about 2.2 x as long as maximum width. Maxilla with cardo surface punctate, each puncture with a short seta; stipes dorsally with long setae along outer edge, ventrally with a group of long setae near insertion of palps and row of setae across middle; galea with 3 strongly sclerotised teeth, dorsally with dense, fine, short setae behind teeth; lacinia simply rounded on margin with short, fine setae on dorsal and ventral surfaces; palps with 4 palpomeres, palpomere 4 longer than palpomeres 1–3 combined and widest before the middle, about 2 x as long as maximum width. Mandibles not visible from above beyond clypeus but visible from the side, apex forming a single tooth and heavily sclerotised, outer edge with coarse, long setae, basal inner area with dense, short ridges. Antennae with 9 antennomeres, antennomere 1 (scape) with swollen distal half that has long, spikey setae, antennomere 2 (pedicel) with a few setae shorter and thinner than on antennomere 1, antennomeres 3–6 glabrous, antennomere 6 very short and flattened against antennomere 7, club of 3 lamellate antennomeres, ratio of lengths of lamellae on antennomeres 7, 8 and 9 1:0.9:0.8, club shorter than antennomeres 2–6 combined, inner face of lamella of antennomere 7 with short setae, edges of lamellae of antennomeres 8 and 9 with a few short setae distally. Labrum membranous, not exposed. Clypeus with anterior face depressed about 45° to plane of clypeus, surface irregularly and coarsely roughened, glabrous, central third depressed to indented anterior margin, margins lateral to indentation broadly rounded, not defined by a ridge, with a few short setae below margin, posterior margin of face defined by a distinct ridge, indented posteriorly in middle; upper portion of clypeus in same plane as frons, lateral margins evenly curved, continuing curve of anterior face and defined by a low ridge, with a few short setae below lateral margin, width across posterior margin 2.1 x width across anterior margin, width across posterior margin 3 x mid length; combined upper clypeus and frons with coarse, concentric sculpturing, glabrous. Clypeofrontal suture straight, largely obliterated on lateral thirds, shallow groove across the middle. Frons without armature, posterior edge and inner to and behind eyes smooth, contrasting with concentric sculpturing on disc, width of frons across eyes 1.1 x interocular space at base of eye canthus; ocular canthi short, impacting on eye shape, most of eye below level of lateral margin of frons, canthi and lateral margin of frons with a few stout, yellow setae. Pronotum without armature, disc glabrous and smooth, maximum width 1.7 x mid length, outer lateral edge with long, brown setae, anterior of disc with a conspicuous furrow set back from slightly raised and darker strip along the margin, surface slightly roughened in front of groove, lateral margins continuing to lateral thirds on posterior margin and defined by a groove, groove largely absent across middle third of posterior margin and indicated by a few punctures, anterior margin evenly curved, posterior margin evenly curved but more so than anterior margin, lateral margins evenly curved, anterior angles with a sharp, slightly acute tooth, posterior angles rounded. Scutellum triangular with extreme apex slightly rounded, surface glabrous and smooth with slight longitudinal depression. Elytra without costae, humerus indistinct, glabrous and largely smooth, striae, including the sutural stria, indicated by indistinct lines of shallow punctures, apical angles with dense, deeper punctures, apices separated, lateral margins defined by a ridge; epipleura glabrous, uniformly wide to about level with metacoxa then tapering to apex. Wings fully developed. Propygidium roughened in apical third, glabrous. Pygidium with basal two-thirds with surface roughened and with scattered long, fine setae, apical third smooth and glabrous, lateral margins defined by a ridge except finer and further forward of the margin across apex. Ventral prothorax with transverse line of long, fine setae; postcoxal process obvious, columnar, rounded at the apex, with stout, brown setae; ventral mesothorax and metathorax with long, yellow setae. Abdominal ventrites except the first and last with transverse band of long, fine setae; ventrite 1 deeply grooved on each side for partial reception of metafemur, central ridged portion with punctures containing a minute seta; apical ventrite with semicircular sulcus with a line of setae near apex. Profemur with long, fine setae on edges and in longitudinal row on ventral middle; protibia with prominent rounded apical tooth and single lateral tooth smoothly rounded, dorsal surface sculptured and with stout, brown setae, stouter along edge between lateral and apical teeth, ventral surface pitted and with stout setae on basal third, longer and finer setae towards inner margin of basal third, spur with deep, longitudinal ventral groove, positioned on inner side of basal tarsomere, low ridge anterior to insertion of tarsi; protarsi inserted just distal to lateral tooth so that distal end of tarsomere 4 is level with apex of apical tooth, tarsomeres 2–4 of similar length, tarsomeres 1 and 5 longer but of similar length, all tarsomeres with a few long, setae, claws simple and symmetrical. Mesofemur broad, 2 x as long as wide, with long setae along anterior margin, longitudinal ridge towards posterior margin with long setae on inner portion becoming shorter and stouter on outer portion; mesotibia widened distally, almost triangular, 1.8 x as long as width across oblique distal margin, laterally with long, fine setae, with 2 transverse bands of stout setae and stout setae on distal margin, inner spur about 1.5 x length of outer spur and apex rounded and with deep longitudinal ventral groove, inner spur pointed with deep longitudinal ventral groove; tarsomeres 1–4 slightly dilated distally but dilation decreasing distally, combined length of tarsomeres 1–2 less than length of inner mesotibial spur, all tarsomeres with a few long setae, claws simple and symmetrical. Metafemur and metatibia remarkably broadened and strongly compressed, metafemur 1.2 x as long as greatest width, metatibia 1.5 x as long as greatest width; metafemur ventrally with scattered stout setae on outer three-quarters, longitudinal ridge with row of stout setae towards inner margin; metatibia with sculpturing similar to upper clypeus and frons, setose along margins, distally with 3 semicircular, transverse ridges and no distal cilia, spurs dilated and flattened, inner one 0.7 mm long, outer curved one 0.5 mm long; metatarsi very short, flattened, claws simple and symmetrical.

Variation. Body 14.0 mm long.

Male. Unknown.

Diagnostic characters. Philcarneum aenigma can be recognised by the following combination of characters. Female clypeus and frons with coarse concentric sculpturing; head and pronotum unarmed; protibiae bidentate, each tooth apically rounded; metafemora and metatibiae greatly broadened and compressed with length:width ratios 1.2:1 and 1.5:1 respectively; metatibiae without distal cilia.

Etymology. A noun in apposition acknowledging the ‘mystery’ identity and occurrence of this species. With the generic name, it refers to ‘Carne’s enigmatic dynastine’, the shorthand we used in Allsopp & Hutchinson (2019).

Distribution and habitat. Known only from the southern coast of New South Wales ( Fig. 10 ); all three localities have a Köppen-Geiger climate of Cfb (oceanic or humid temperate) ( Beck et al. 2018).

Carne (1981) indicated that there was a label on the holotype stating “coastal sand dunes, walking on surface towards dusk”, but this is not now present.

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 1–5. Philcarneum aenigma Allsopp & Hutchinson new genus, new species, holotype female: 1, dorsal view; 2, ventral view; 3, lateral view; 4, head, dorsal view; 5, labels.

FIGURES 6–9. Philcarneum aenigma Allsopp & Hutchinson new genus, new species, ANIC paratype female: 6, mentum and labial palps, ventral view; 7, right mandible, dorsal view; 8, left maxilla, ventral view; 9, right maxilla, dorsal view.