Cavonus, Sharp, 1875

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 : 458-459

Key to Cavonus males (modified from Carne 1957)

1. Clypeus with sides sinuate ( Carne 1957, Fig. 334); elytra with dorsal striae obsolete posterior to subapical calli; basal pronotal ridge continuous...................................................................................... 2

- Clypeus rounded ( Carne 1957, Figs. 343, 351); elytra with dorsal striae continuing over subapical calli; basal pronotal ridge sometimes partially obsolete............................................................................ 3

2. Pronotum armed with lateral horns ( Carne 1957, Fig. 339); frons without a transverse excavation behind clypeofrontal ridge ( Carne 1957, Fig. 334); pronotal impression continuous to basal margin; genitalia as in Carne (1957, Figs. 341, 353); body 14–22 mm long; southern South Australia ................................................ C. armatus Sharp, 1875

- Pronotum with lateral convex elevations, frons with a transverse excavation behind clypeofrontal ridge ( Carne 1957, Fig. 340); basal convexity of pronotum interrupted by a shallow depression extending to basal margin; genitalia as in Carne (1957, Figs. 342, 350); body 12–21 mm long; southern South Australia ................................. C. sharpi Blackburn, 1888

3. Apical pygidial ridge glabrous........................................................................... 4

- Apical pygidial ridge setose............................................................................. 5

4. Pronotum with lateral horns; mentum highly compressed; body about 12 mm long; southwestern South Australia ........................................................................................... C. acutifrons Lea, 1917

- Pronotum with lateral convex elevations; mentum very conspicuous, depressed, strongly reflexed at ligula; body 15–17 mm long; southeastern South Australia, northwestern Victoria ................................ C. niger ( Blackburn, 1888) .

5. Pronotum with a pair of anteromedian tubercles ( Carne 1957, Fig. 351), with strong convexity at base and with basal ridge either continuous or obsolete; scutellum punctate or rugose on disc; genitalia as in Carne (1957, Figs. 344, 347); body 11–12.5 mm long; southeastern South Australia, northwestern Victoria ............................ C. bidens ( Blackburn, 1896)

- Pronotum with single anteromedian tubercle; disc of scutellum either coarsely punctate or bearing submarginal garland of small punctures ( Carne 1957, Fig. 353); genitalia unknown or as Figs. 9–10 or Carne (1957, Figs. 345, 349).................. 6

6. Pronotum with small elevated tubercle ( Carne 1957, Fig. 348); basal ridge obsolete in lateral thirds, sometimes discernible on median third; elytral punctation moderately impressed, dorsal stria obsolete just before apical calli; southwestern New South Wales ................................................................................ C. leai Carne, 1957

- Pronotum with short, stout, erect anteromedian tubercle ( Carne 1957, Fig. 338); basal ridge continuous; elytral punctation deeply impressed, dorsal striae not obsolete at subapical calli; southwestern South Australia and southern Western Australia .. ................................................................................................... 7

7. Apical palpomere of mandibular palp cylindrical; pronotal impression with medial elevation ( Figs. 3, 6 ); clypeal surface ( Fig. 7 ) heavily punctate; scutellum ( Fig. 3 ) with submarginal garland of punctures; genitalia as in Carne (1957, Figs. 345, 349); body 18–19 mm long; southwestern South Australia, southeastern Western Australia ( Fig. 28 )................................................................................................... C. sculpturatus Blackburn, 1888

- Apical palpomere of mandibular palp conical, widest and truncate at apex; pronotal impression uniformly concave ( Figs. 17, 20 ); clypeal surface ( Fig. 21 ) with fine sparse punctures; scutellum ( Fig. 17 ) disc coarsely punctate; genitalia as in Figs. 23–24 ; body 15.5 mm long; southwestern Western Australia ( Fig. 28 )........... C. fovealacus Hutchinson & Allsopp , new species

Figures

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

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 17–25. Cavonus fovealacus new species, holotype male. 17, Dorsum; 18, venter; 19, lateral; 20, head, lateral; 21, head, dorsal; 22, pygidium; 23, parameres; 24, aedeagus, lateral; 25, labels.