Hyalonthophagus pulcher Deschodt & Davis, 2019

Deschodt, Christian M., Davis, Adrian L. V. & Sole, Catherine L., 2019, A beautiful new species of Hyalonthophagus Palestrini & Giacone, 1988 (Coleoptera Scarabaeidae: Scarabaeinae), from the Northern Cape Province, South Africa, Zootaxa 4648 (1), pp. 194-200 : 195-199

Hyalonthophagus pulcher Deschodt & Davis , new species

Figs. 1–4

Type specimens. Holotype ♂ mounted on card with aedeagus glued on triangle below: Farm: Nelspoortjie (25) | S29.92191° E22.42507° | 1120m 10-12.iii.2006 | Davis & Deschodt, TMSA . Paratypes: 84 spec. same data as holotype, 25 UPSA , 25 TMSA, 34 SANC; 25 spec. Farm : Deelpan,N-Cape | S29.56306° E22.34164° | A.Davis & C.Deschodt | 19-21.iii.2003, TMSA ; 4 spec. Farm : Mariba (18) | S29.67961° E22.06762° | 18-20.iii.2005 | Davis & Deschodt ; 6 spec. Farm : Brakpoort (12) | S29.94447° E22.75995° | 23-25.iii.2004 1072m | ALV. Davis & C. Deschodt, SANC ; 6 spec. Farm : Modderfontein (11) | S29.91893° E22.75888° | 23-25.iii.2004 1096m | ALV. Davis & C. Deschodt, all UPSA ; 54 spec. Farm : Boesmansberg (26) | S29.49410° E23.12409° | 1080m 10-12.iii.2006 | Davis & Deschodt, TMSA , 20 UPSA, 20 TMSA, 14 SANC; 3 spec. Farm : Sonderpan (29) | S29.22260° E21.77542° | 1040m 16-18.iii.2006 | Davis & Deschodt, 1 UPSA , 1 TMSA, 1 SANC; 1 spec. Farm : Herbou (27) | S29.49410° E23.12409° | 1080m 13-15.iii.2006 | Davis & Deschodt, UPSA ; 2 spec. Farm : Rooiput (30) | S29.30289° E21.61613° | 990m 16-18.iii.2006 | Davis & Deschodt, 1 UPSA , 1 SANC.

Description of holotype, male. Body: 8.2 x 4.6 mm (maximum length with head extended). Habitus multicoloured with head and pronotum metallic green-cyan, antennae black, elytra dark red-orange and brown with a metallic green-cyan sheen and, pygidium dark purple and black.

Head. Clypeus anteriorly rounded with very short black setae regularly and closely spaced pointing away from the edge; anterior carina slightly curved anteriorly; second carina modified into a triangular horn; surface covered by small punctures separated by about two to three puncture diameters, area in front of anterior carina also with larger punctures and very fine, yellow associated pilosity.

Pronotal disc. Under zero magnification, surface of pronotum smooth, glabrous and unsculptured; under 40x magnification, surface very finely shagreened, covered with minute punctures spaced by about three puncture diameters.

Elytra. Surface sculpture of elytral interstriae similar to pronotum, but more strongly shagreened. Sutural interval part of a dark band that surrounds each elytron. Striae clearly punctate with punctures about four puncture diameters apart.

Anterior legs. Tibiae quadridentate on outside with first denticle smallest, finely serrated between denticles except last two with no serration, yellow setae pointing downward on inside margin. Tarsi unmodified with last article almost as long as the first four combined; terminal spur spatulate to some degree.

Meso- and metalegs. Tibiae slightly flattened, widening towards apex, three serrations on outside margin with black setae on inside and outside margins; meso and metatarsi unmodified, length of articles different with first being almost as long as the rest combined; terminal spurs unmodified.

Aedeagus. Symmetrical, similar to other species of Hyalonthophagus ( Fig. 2 ).

Sexual dimorphism. In females, second clypeal carina prominent, not modified into a horn as in males.

Variability. Although the iridescence of individual specimens varies with changes in the observation angle the colouration mostly ranges from slightly darker to slightly lighter specimens in the type series. Some specimens in the type series are marginally smaller.

Etymology. The specific epithet is masculine and is derived from the Latin word “pulcher” meaning beautiful or handsome in English.

Distribution, ecology, conservation status, and potential threats. A ten-year survey of dung beetle distribution across 50200 km 2 in the Northern Cape, South Africa ( Davis et al. 2016), shows that the new species is restrict- ed to a small area of uplands at the southern edge of the Orange River Valley between Groblershoop, Prieska and Britstown. This area comprises the extreme northeast edge of the Bushmanland bioregion of the Nama Karoo biome just to the south of the Eastern Kalahari Bushveld bioregion of the Savanna biome (Mucina & Rutherford 2006). It also comprises the western end of a subregion defined from ordination analysis of the dung beetle survey data that was described as Gariep Karoo ( Davis et al. 2016). The small disjunct range of the new species is bordered by the cool Highveld Grasslands plus Upper Karoo to the east and south, Kalahari sandveld to the north, and, increasingly arid, Bushmanland Karoo to the southwest.

The species occupies a narrow range in altitude (1075.4 ± 50.0 m) in a dry (annual rainfall = 209.9 ± 13.3 mm) warm (annual temperature (max. + min. / 2) = 18.3 ± 0.4 °C) area isolated to the south of the Orange River. In adjoining regions and areas, average altitudinal and climatic values are roughly similar if a little warmer (Kalahari deep sands: 1053 m, 194.8 mm, 19.2 °C), higher, moister and cooler (Upper Karoo: 1330.7 m, 280.7 mm, 15.2 °C), or, lower, dryer and warmer (southwest Bushmanland: 924.8 m, 140.9 mm, 19.3 °C) ( Davis et al. 2016). Within its range at the southern edge of the Orange River valley, it has been recorded primarily in scrub / grassland on loamy sands and very sandy loamy soils found around saline pans, especially, on the farms, Midelka, Brierspan, Tarkaskop, Boesmansberg and Nelspoortjie (average of 13.3 specimens / study site (range 0-38 at 22 study sites); each site comprising three traps baited with a composite of sheep and cattle dung over two days) (Davis et al. unpublished).

Although Hyalonthophagus pulcher Deschodt & Davis , new species is restricted to the northeast of the Bushmanland Bioregion, its known extent of occurrence is over 6500 km 2. The vegetation of this area is relatively unmodified and used for sustainable mixed sheep and cattle farming. Therefore, as the new species is readily attracted to these dung types, it is assessed as least concern (LC) according to the IUCN red list categories.

Differential diagnosis. This new species is morphologically most similar to Hyalonthophagus alcyon (Klug, 1855) new combination. It can easily be separated as the colour of the elytra differs from that of the pronotum unlike in H. alcyon . It also shows an isolated south western distribution, which does not overlap with that of H. alcyon .

Figures

FIGURE 1. Habitus of the holotype of Hyalonthophagus pulcher Deschodt & Davis, new species. Scale bar = 2.0 mm.

FIGURE 2. Genitalia of Hyalonthophagus pulcher Deschodt & Davis, new species.A, aedeagus of the holotype in lateral view; B, the same in dorsal view; C, female genitalia of a paratype specimen from the type locality. Scale bar for A–C = 0.5 mm.

FIGURE 3. Map showing the distribution of Hyalonthophagus pulcher Deschodt & Davis, new species in the Bushmanland Bioregion of South Africa. The locality data include unpublished records collected in the study of Davis et al. (2016) and those for non-type specimens.

FIGURE 4. Map showing the distribution of four species of Hyalonthophagus Palestrini & Giacone, 1988, known from Southern Africa.