Scarabaeus (Scarabaeolus) namibensis 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 : 5-6

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

Fig. 17–20

Type locality. S.W. Afr. [ Namibia], 60 km NE Gobabeb.

Type material. HTm from type locality .

PT (59): 1 from S.W. Afr., Namib, Bloedkoppe , leg. Endrödi-Younga 18.XI.1974; \\ 1 from same loc. but coll. 7.VII.1978; \\ 2 from S.W. Afr., Namib, 22 km NE Gobabeb, leg. Endrödi-Younga 28.II.1975; \\ 1 from S.W. Afr., Namib, 32 km NE Gobabeb, leg. Endrödi-Younga 28.II.1975; \\ 2 from S.W. Afr., Namib, 42 km NE Gobabeb, leg. Endrödi-Younga 28.VIII.1975; \\ 2 from S.W. Afr., Namib, 52 km NE Gobabeb, leg. Endrödi-Younga 20.I.1975; \\ 2 from same loc. but coll. 26.I.1975; \\ 1 from same loc. but coll. 5.VI.1975; \\ 2 from S.W. Afr., Namib, 60 km NE Gobabeb, leg. Endrödi-Younga 26.I.1975; \\ 2 from S.W. Afr., C. Namib, Gobabeb, 12 km NE, leg. Endrödi-Younga 7.VII.1978 [black with more distinctly punctate elytra]; \\ 43 from S.W. Afr., Kaokoveld, Kunene Riv. , 44 km S, leg. Penrith & Müller 7.VII.1984 [two specimens of this series of 45 are S. knobeli , one of them shown in Fig. 21–24 ] .

HT and all PT at TMSA.

Etymology. Named for the Namib desert biome.

Description of holotype. Length 13.5 mm; head, pronotum, venter and legs black, elytra combination of black and reddish brown.

Head with a broad glabrous to micropunctate medial area throughout length. Clypeus with teeth upturned, spaces between them U-shaped and wider between medial pair than between medial and lateral teeth; bases of teeth longitudinally granulate, farther posteriorly under each lateral tooth with a diffuse patch of short rusty setae. Genae separated from clypeus by V-shaped fissures, their anterior terminations sharp and weakly curved out, posterior corners rounded toward eyes; surface in front of eyes granulorugose, with a few scattered coarse punctures. Frons with a very weakly indicated and medially interrupted transverse carina. Vertex medially micropunctate, laterally with a few large punctures. Antenna yellowish brown.

Pronotum. Bordered all around, lateral margins finely crenulate and setose, base with a small medial lobe; front angles obtuse, hind corners obliquely merging into base. Sagittal line wide, glabrous, present throughout length; remaining surface unevenly coarsely punctate, size of punctures diminishing laterally and anteriorly.

Scutellum . Exposed, small, triangular.

Elytra. With striae finely and densely punctate, intervals weakly convex (first through fourth, basal third of fifth) to flat (sixth and seventh) and impunctate (first, sixth and seventh) or punctate very sparsely (second through fifth). Humeri small, confined to sixth interval.

Pygidium . Semilunar, bordered all around, finely punctate laterally and shagreened medially.

Venter. Metasternal process lunate, with a rounded tip; metasternal plate and abdominal ventrites very sparsely micropunctate.

Legs. Protibia weakly incurved at level of second tooth, spaces between teeth equal, last tooth rudimental; entire lateral margin finely serrate, setose only in proximal half; medial margin microgranulate, setose only in distal half. Mesotibia with two spurs. Both meso- and metatibia with two transverse carinae. Femoral setation brownish yellow.

Aedeagus. With parameres and phallobase of equal length; left paramere in proximal half of length with a medium-size ventral tooth inclined toward phallobase; tips of parameres in dorsal view inflated, in lateral view produced into short beaks.

Variability. Length 8–14 mm, coloration of elytra varies slightly in the extent of black and shades of dark red or brown, some specimens may be entirely black; females have shorter protibiae without distal inward curvature; proximal protibial tooth ranges from rudimental to about one-third the length of preceding tooth.

Comparison. This new species is similar to S. knobeli Ferreira ( Fig. 21–24 ), with which it is partly sympatric. However, S. knobeli has the pygidium terminating in a small, outward curved spine and differs more subtly also in other respects: the protibia lacks any indication of a distal inward curvature, has the medial margin coarsely serrate, and the space between the third and fourth teeth is distinctly smaller than that between preceding teeth; the mesotibia has only one spur; and, in dorsal view, the paramere tips are not inflated.

Figures

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.