Hybovalgus calvus, Ricchiardi, 2017

Ricchiardi, Enrico, 2017, Revision of Chinese mainland Hybovalgus Kolbe, 1904, with description of a new species, and Excisivalgus Endrödi, 1952 reduced to synonymy with Hybovalgus (Coleoptera: Scarabaeidae), European Journal of Taxonomy 340 (340), pp. 1-32 : 13-16

Hybovalgus calvus sp. nov.

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Fig. 6

Diagnosis

Hybovalgus calvus sp. nov. can easily be separated from all other Chinese Hybovalgus (except from H. jordansi ) by the V-shaped protrusion at the posterior margin of the pronotum ( Fig. 6A, D, J ). The female pygidium apex lacks a protrusion. The parameres are different from those of H. bioculatus in the C-shaped apex ( Fig. 6H ). Females of Hybovalgus calvus sp. nov. can be distinguished from those of H. jordansi by the prominent testaceous scale tufts at the posterior margin of the pronotum; by the fringe of small, testaceous scales at the pygidial apex, instead of prominent, double-pointed testaceous scale tufts. The apex of the parameres of both species ( Figs 6H , 8I ) are inwardly C-shaped, but in H. jordansi they are thinner and tapered.

Etymology

The name comes from the Latin word “ calvus ”, meaning glabrous, as the integument of this species appears at first glance.

Type material

Holotype

VIETNAM: ♂, Tonkin , Montes Mauson , Apr.–May, 2000–3000’, H. Fruhstorfer leg. ( MNHUB).

Paratypes

VIETNAM: 1 ♂ ( ERC), 1 ♀ ( MNHUB), same data as for HT.

CHINA: 1 ♂, Hainan, Wuzhishan , 1 Jun. 2009 ( ERC).

Description

Holotype

MEASUREMENTS. Length 8.2 mm; width 5.1 mm.

BODY. Colour mostly black, with propygidium and pygidium dark castaneous. HEAD. Black, slightly shiny, covered with large round punctures; frons and vertex covered with small, recumbent, testaceous scales that do not form scale tufts. Clypeus black, anteriorly sinuate, suctorial brush long.

PRONOTUM. Black, nearly glabrous, trapezoidal, slightly crenate at sides, laterally depressed at center of lateral margins; anterior angle acute, posterior angle right-angled, with apex rounded; posterior margin with central part showily produced backwards, V-shaped, with apex rounded. Carinae rounded, parallel, ending around middle of disk; central small carina not present; lateral carinae not present; with 2 testaceous barely noticeable central carina scale tufts; without any other scale tufts. Covered with small, decumbent, scattered, testaceous scales.

SCUTELLUM. Black, long, apically rounded, covered with small, decumbent, thick, testaceous scales.

ELYTRA. Black, slightly shiny, mostly glabrous, with barely noticeable juxtascutellar depression. Humbones slightly prominent, without scale tufts; anteo-central part of disk covered with hardly noticeable small, thick, decumbent black scales.

PROPYGIDIUM. Dark castaneous, covered with thick, decumbent, small, coffee bean shaped, testaceous scales that form two small propygidium scale tufts; centre of posterior margin depressed; cones short and blunt.

PYGIDIUM. Dark castaneous, wider than long, slightly depressed at sides in ventral half. Covered with thick, decumbent, small, coffee grain shaped, testaceous scales which form a fringe of long scales at apex. Apex rounded, without projection. Under apex, in ventral view, there is a hollowed, semicircular, glabrous, horizontal surface.

PROTIBIA. Black, with 5 external teeth: 1–3, long, 4–5 smaller, all rounded at apex. Teeth 3–4 closer to one another than 1–3; tooth 5 rather spaced apart from 4 ( Fig. 6B ).

MESO- AND METAFEMUR. Black, with a fringe of small, testaceous scales at centre of posterior margin which do not form a small scale tuft.

METATIBIA. Black, centrally enlarged at posterior margin, without a tooth at centre. First metatarsomere long 1.8 times the length of second.

ABDOMEN. Dark castaneous, covered with thick, recumbent, testaceous scales, scattered at centre of 1–3 visible sternites. Anal sternites, with same scales but centrally glabrous.

Paratype ♀ (differences from HT)

MEASUREMENTS. Length 9.5 mm; width 5.7 mm. Body dark castaneous.

The female is quite similar to the male, not showing great differences in the shape of the posterior margins of the pronotum or pygidium apex. The first is pointed at the apex, the latter is regularly rounded. The propygidium is much wider than long, shaped as in the male but with a small depression close to each superior corner.

Type series variability

Males: length 8.0– 8.4 mm; width 4.7–5.3 mmm. A PT ♂ has the propygidium, pygidium and abdomen black.

Flight period

The Vietnamese types were collected from May to early June at an elevation of 700–1500 m.

Distribution

Present in northern Vietnam and China (Hainan).

Figures

Fig. 6. Hybovalgus calvus sp. nov. A–C, H–I. HT ♂ (MNHUB). A. Habitus, dorsal view. B. Protibia. C. Pygidium. H–I. Aedeagus (grey: parameres; white: phallobase). H. Dorsal view. I. Lateral view. D–G. PT ♀ (ERC). D. Habitus, dorsal view. E. Protibia. F. Pygidium, frontal view. G. Pygidium, lateral view. J–K. PT ♂ (ERC). J. Habitus, dorsal view. K. Propygidium and pygidium.

Fig. 8. A–F. Hybovalgus sexdentatus Arrow, 1944. A–B. ♂ (ERC). A. Habitus, dorsal view. B. Propygidium and pygidium. C–D. ♀ (ERC). C. Habitus, dorsal view. D. Propygidium and pygidium. E–F. PLT, ♂ (NHM). E. Aedeagus, dorsal view. F. Aedeagus, lateral view. G–J. Hybovalgus jordansi (Endrödi, 1952). G–H. ♂ (ERC). G. Habitus, dorsal view. H. Propygidiun and pygidium. I–J. PT, ♂ (HNHM). I. Aedeagus, dorsal view. J. Aedeagus, lateral view. K–N. Hybovalgus fulvosquamosus Moser, 1904. K–L. ♂ (ERC). K. Habitus, dorsal view. L. Propygidiun and pygidium. M–N. LT, ♂ (MNHUB). M. Aedeagus, dorsal view. N. Aedeagus, lateral view. Drawings: grey parts: parameres; white parts: phallobase.