Cavonus sculpturatus Blackburn, 1888

Hutchinson, Paul M. & Allsopp, Peter G., 2020, Cavonus Sharp, 1875 (Coleoptera: Scarabaeidae: Dynastinae: Pentodontini Pseudoryctina) in Western Australia with description of a new species and the female of Cavonus sculpturatus Blackburn, 1888, Zootaxa 4852 (4), pp. 449-460 : 450-455

Cavonus sculpturatus Blackburn, 1888

( Figs. 1–16 , 28 )

Cavonus sculpturatus Blackburn, 1888: 223 ; Carne 1957: 132, Fig. 335 (scutellum), Fig. 338 (head and pronotum), Figs. 345, 349 (parameres), Map 17; female (as Epironastes nigrisetosus allotype): 126, Fig. 326 (head and pronotum), Map 17; Endrődi 1974: 38–39, Fig. 55 (parameres); Endrődi 1985: 386, Fig. 1402 (parameres); Krajcik 2005: 39; Krajcik 2012: 66; Dechambre 2005: 70, unnumbered image (adult).

Type. Holotype ♂ (by monotypy): Cavonus sculpturatus, Blackb. // Australia Blackburn Coll. B.M. 1910–236. // 1409 // Type // Type H. T. // mentum on card // genitalia on card [in NHML, examined] ( Figs. 1–2 ). Blackburn (1888) saw a single male collected by Tate at “Ouldea” [ Ooldea , South Australia, 30.459°S, 131.836°E].

Other specimens examined. 1♂: Cavonus sculpturatus P.B. Carne det. 1952 // 49-1101 Forrest [in WAM] ; 1♂: Cavonus sculpturatus Blkb. P.B. Carne det. 1978 // W.A.M. Reg. No 78/124 // Forrest aerodrome W. Australia 28.x.1962 A. Elliot [in WAM] ; 1♀: 49-1104 Forrest //? Epironastes nigrisetosus mihi P.B. Carne comp. with type // Allotype (see Carne 1957: 126) [in WAM; register gives M.W. Woodie as the collector] .

Redescription. Male ( Figs. 1 , 3–10 ). Body black, with brown suffusion on meso- and metalegs and elytra, 19.6 mm long, 11.5 mm wide at elytra. Mentum setose on disc, compressed near ligula and reflexed; palps short with palpomere 4 cylindrical, basal two-thirds foveate; labrum concealed, medially bearing long yellow setae. Antennae with 10 antennomeres, scape and pedicel setose, club slightly shorter than shaft, ovate and setose on inner face. Clypeus transverse, dorsally subcircular in outline, margins strongly raised, truncate face moderately deep, slightly produced in middle of base and sparsely setose, clypeal surface heavily punctate; clypeofrontal ridge strongly elevated. Frons concentrically rugulose; ocular canthi at angle to clypeus, anterior margin straight and bearing setae, surface rugulose. Pronotum with sides slightly contracted before anterolateral angles, anterolateral angles not at right angles, anterior margin with strong erect process, with longitudinal ridge extending posteriorly into impression, latter defined by rounded lateral elevations, extending over basal convexity as a broad shallow depression, impression and anterior part of pronotum with large shallow incomplete often connected punctures, lateral and basal convexities with light sparse punctation, basal margin trisinuate with medial and paramedial shallow depressions. Scutellum with submarginal garland of punctures. Each elytron with sutural striae linear-punctate, disc with welldefined punctate striae, with occasional random punctures on intervals 2, 4, and 6, surface finely microreticulate, epipleurae with lateral setae extending as far as abdominal sternite 1. Pygidium moderately convex with long brown setae at sides, with shorter setae across base, rugose across basal half, becoming sparsely punctate towards apex, apical ridge very strongly broadened and setose. Postcoxal process tapering, densely setose. Posterior margins of all abdominal sternites setose across middle. Coxae bearing abundant dark-brown vestiture; protibiae broad, evenly and strongly toothed, protarsomere 5 longer than protarsomere 1; metafemora moderately stout, unisulcate; metatibiae stout, length 2x apical width, basal carina bearing long setae; medial carina with long blunt cilia and bristles, spurs subspatulate, smaller slightly curved, larger spur straight. Genitalia of holotype broken.

Female ( Figs. 11–16 ). Body dark brown tending black, 16.7 mm long, 9.2 mm wide at elytra. Mentum wide at base, slightly narrowed to ligula, strongly reflexed, rounded at apex, disc setose; palps short [palpomere 4 of mandibular palp missing], labial palps with apical segments cylindrical; mandibles exposed, evenly rounded. Antennae with 10 antennomeres, scape and pedicel setose, club subovate, slightly shorter than shaft, inner face setose. Labrum concealed, bearing long yellow setae. Clypeus evenly arcuate, subcircular, apex not reflexed, lateral ridges distinct and slightly raised, truncated face not produced medially, sparely setose [setae broken], surface evenly coarsely punctate; clypeofrontal suture slightly raised, transverse-linear. Frons concentrically rugulose; ocular canthi rugulose, at angle to clypeus, anterior margin straight and bearing setae, lateral margin subequal to outline of eye. Pronotum with anterior margin membranous, anterolateral angles slightly acute, basolateral angles rounded, basal margin bisinuate with shallow paramedial depressions, basal ridge complete, widest at midlength, surface distinctly punctate becoming denser and larger at anterior and posterior margins, anterior margin medially with slight swelling preceding a flattened region bearing semi-annulate punctures tending rugulose, midline impunctate, surface slightly convex in lateral view, basal convexity absent. Scutellum bearing a garland of submarginal punctures, disc and base impunctate. Each elytron with sutural striae linear-punctate, disc with deeply impressed punctures forming distinct striae, intervals with random punctures, lateral epipleural setae absent. Pygidium moderately convex, disc concentrically punctate, denser and rugulose across base, finer and sparser at apex, bearing microsetae laterally, apical ridge slightly broadened and punctate medially, glabrous. Postcoxal prosternal process long, narrow, abundantly clothed with long dark brown vestiture, apex tapering posteriorly and glabrous. Abdominal sternites 1–5 punctate across posterior margin medially, laterally punctures bearing setae over entire surface, posterior margin of sternite 6 densely punctate bearing microsetae with sparse punctures across base. Protibiae stout, tridentate, denticles evenly spaced and broad [left protarsomeres 1–5 and right protarsomeres 1–4 missing]; metafemora stout, unisulcate; metatibiae moderately contracted before apex, length about 2.5x width, stout, apex broad and bearing short, fine cilia set about 1 width apart, bicarinate, basal carina bearing long setae, medial carina bearing long cilia and longer bristles, apical spurs stout, subspatulate, slightly curved; metatarsomere 1 moderately unilaterally expanded [left metatarsomeres 2–5 and right metatarsomeres 3–5 missing].

Discussion. Known only from Forrest and Ooldea on the Nullarbor Plain ( Fig. 28 ). The female specimen that Carne attributed to E. nigrisetosus was collected at Forrest by M.W. Woodie and, along with a male C. sculpturatus and three other specimens, was donated to the WAM in one lot. The morphological combination of an arcuate clypeal margin and lack of a transverse ridge adjoining antennal angles anterior to clypeofrontal suture separates it from Epironastes and places it in Cavonus . Its collection with males of C. sculpturatus and sharing the characteristic garland of punctures on the scutellum, similar coloured vestiture and similar size show that it is the female of C. sculpturatus .

Although the holotype has mandibular palpomere 4 missing, Carne’s (1957) generic description for Cavonus states palps “cylindrical”. Both males examined from Forrest (WAM) have the mandibular palpomeres foveate on the basal two-thirds. The parameres from the holotype are broken near the apices ( Fig. 9 ); complete versions are shown in Carne (1957, Figs. 345, 349).

We were intrigued with the double irony of the collector Woodie, at Forrest, on the Nullarbor Plain!

Figures

FIGURE 28. Collection localities of Cavonus fovealacus new species and C. sculpturatus Blackburn, 1888 in Western Australia and South Australia.

FIGURES 1–2. Cavonus sculpturatus Blackburn, 1888, holotype male. 1, Dorsum; 2, labels.

FIGURES 3–10. Cavonus sculpturatus Blackburn, 1888, holotype male. 3, Dorsum; 4, venter; 5, lateral; 6, head, lateral; 7, head, dorsal; 8, pygidium; 9, parameres, apices missing; 10, aedeagus, lateral.

FIGURES 11–16. Cavonus sculpturatus Blackburn, 1888, female (allotype of Epironastes nigrisetosus). 11, Dorsum; 12, venter; 13, lateral; 14, head lateral; 15, head, dorsal; 16, pygidium.