Scarabaeus (Scarabaeolus) lizleri Zidek and Pokorný, 2018

Zidek, Jiri & Pokorný, Svatopluk, 2018, New species of the Scarabaeus subgenus Scarabaeolus Balthasar, with a review of the subgenus (Scarabaeidae: Scarabaeinae: Scarabaeini), Insecta Mundi 611, pp. 1-35 : 3-5

Scarabaeus (Scarabaeolus) lizleri Zidek and Pokorný , sp. n.

Fig. 9–12

Type locality. RSA, Northern Cape Province, 30 km SE of Alexander Bay.

Type material. HTm from type locality, leg. R. Lízler 9.X.2000 . PT (179): 172 from type locality, leg. R. Lízler 9.X.2000; \\ 2 from RSA, Richtersveld, Port Nolloth ,

leg. Endrödi-Younga 4.X.1976; \\ 1 from Richtersveld, Manganese mine, leg. Endrödi-Younga 10.X.1976 ; \\ 2 from S.W. Afr. [ Namibia], Namib, Obib dunes, leg. Endrödi-Younga 20.IX.1973 ; \\ 2 from S.W. Afr. [ Namibia], S. Namib, Oranjemund , leg. Endrödi-Younga 28.VII.1981 .

HT+10 PT at TMSA, 10 PT at BMNH, 10 PT at OXUM, 10 PT at MNHB, 8 PT at NMPC, 131 PT at GWPC.

Etymology. Named for Robert Lízler of Hradec Králové, Czech Republic, who collected nearly the entire type series.

Description of holotype. Length 15 mm. Black with reddish-orange elytra, glossy.

Head. Clypeus without ventral keel, teeth weekly upturned, spaces between them U-shaped, space between medial teeth wider than that between medial and lateral teeth; anterior part with sparse asperate and setose punctures that posteriorly change to setose granules. Genae separated from clypeus by narrow excisions, their sculpture somewhat finer than that of clypeus, front end of each gena sharply pointed. Clypeus/frons boundary with an inconspicuous broad and smooth tubercle. Smooth sagittal line present throughout length, narrow on clypeus, widest on frons and narrowing toward vertex. Pubescence rusty brown, antennal club brownish yellow.

Pronotum. Bordered all around, with a distinct smooth sagittal line, disc with sparse deep, setose punctures that become smaller and more closely spaced anteriorly and laterally. Lateral margins evenly rounded, coarsely serrate, with long hairs. Front angles obtuse, pointing outward, hind corners evenly rounded. Basal margin lined by a shallow groove with irregularly spaced setose punctures; medial part of base weakly lobate.

Scutellum . Exposed, small, triangular.

Elytra. With humeri well developed, indistinctly striate, striae micropunctate. Intervals smooth and glossy, first interval flat on disc, convex and sparsely punctate posterolaterally. Second through fifth intervals nearly impunctate; sixth and seventh intervals weakly arched; suture and first interval black.

Pygidium . Obliquely triangular, bordered all around, smooth on disc and punctate near margins.

Venter. Metasternum with posterior longitudinal furrow and keeled anterior process. Ventral pubescence dark brown.

Legs. Protibia curved inward at level of second tooth, lateral margin densely serrate, medial margin densely granulose. Profemoral anteroventral carina without proximal tooth. Mesotibia with two spurs. Lateral margin of metatibia without transverse carinae. Pubescence dark brown.

Aedeagus. Parameres shorter than phallobase, in lateral view dorso-ventrally parallel- sided, without ventral tooth and with truncated tips.

Variability. Length 10–15 mm, elytra prevalently bright to dark reddish orange, frequently with scattered small blackish spots, but in some specimens entirely dark brown with reddish hue.

Comparison. The dorsal habitus of the new species is indistinguishable from S. rubripennis (Boheman) ( Fig. 13–16 ). In ventral view S. lizleri sp. n. has a larger and more keeled metasternal process, but this cannot serve as a reliable diagnostic character. However, the two species can be readily separated on the presence of a large, sharp anteroventral tooth at the proximal end of the profemur in S. rubripennis , which is absent in the new species. The aedeagi of both species do not have a ventral tooth (merely a minute, barely noticeable tubercle) and differ only in proportions, with the phallobase longer than the parameres in S. lizleri and vice versa in S. rubripennis . Another species with reddish-brown but much darker elytra is S. knobeli Ferreira from southern Angola (HT) and northwestern Namibia ( Fig. 21–24 ), which can be separated from the other two species on having sparsely and shallowly punctate elytral intervals, only one mesotibial spur, and pygidium terminating in a short, outward curved spine.

Biology. According to R. Lízler (in litt.) the type locality is about 10 km from the shore, only 10–20 m above the sea level, and has the character of a semidesert with small dunes and interspersed rocky outcrops. Vegetation consists of sparse “tamarysk” brush and succulents, and herbivorous mammals include lagomorphs, small antelope, goat and sheep; large ruminants are absent. At the time of capture of S. lizleri the temperature fluctuated between close to freezing at night and 30–35° C at mid-day, and the area experienced strong winds. The beetles were taken at human dung between 8 and 11 a.m. and again in the late afternoon and at dusk. It thus is a diurnal–crepuscular species that avoids daily thermal maxima more than minima, because in the early morning beetles were observed flying although the temperature was still only about 5° C.

The localities of the type series are in Northern Cape Province close to the southwestern RSA / Namibia border and just across the mouth of the Orange River in southernmost Namibia (Oranjemund, TMSA specimens), whereas localities of S. rubripennis are more to the north in the Namib desert—Kuisip (HTm), Namtib dunes (TMSA specimens) and Sessriem (BMNH and OXUM specimens). The two species thus are close neighbors and the question arises whether north of the Orange River they could not be sympatric, separated by diel activity or chemical stimuli. We have found no evidence of hybridization in the morphology of about 200 specimens examined.

Figures

Figures 9–16. Scarabaeus (Scarabaeolus) spp. 9–12) Scarabaeus (Scarabaeolus) lizleri sp. n., HTm, 15 mm. 9) Dorsal habitus. 10) Ventral habitus. 11) Aedeagus, dorsal. 12) Aedeagus, left lateral. 13–16) Scarabaeus (Scarabaeolus) rubripennis (Boheman), 14 mm. 13) Dorsal habitus. 14) Ventral habitus. 15) Aedeagus, dorsal. 16) Aedeagus, left lateral.

Figures 17–24. Scarabaeus (Scarabaeolus) spp. 17–20) Scarabaeus (Scarabaeolus) namibensis sp. n., HTm, 13.5 mm. 17) Dorsal habitus. 18) Ventral habitus. 19) Aedeagus, dorsal. 20) Aedeagus, left lateral. 21–24) Scarabaeus (Scarabaeolus) knobeli Ferreira, 12 mm. 21) Dorsal habitus. 22) Ventral habitus. 23) Aedeagus, dorsal. 24) Aedeagus, left lateral.