Scarabaeus (Scarabaeolus) fragilis 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 : 6-7

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

Fig. 25–28

Type locality. RSA, Northern Cape Province, Springbok, Lammerhoek.

Type material. HTf from type locality, leg. Vári & Goode 5–8.IX.1962. No other specimens. HT at TMSA .

Etymology. In reference to fragile condition of the unique specimen.

Description. Length 12.5 mm. Head black; pronotum black, with lateral margins and front angles dark brown; elytra, entire venter and legs chestnut brown. Metatarsi incomplete.

Head. Clypeus with teeth upturned, spaces between medial and lateral teeth U-shaped and equally wide, entire surface finely and densely granulorugose, with short black, forward-recumbent setae and longer black setae on lateral margins. Genae anteriorly pointed, posteriorly rounded toward eyes, space between them and clypeal teeth V-shaped. Frons with a low transverse carina medially extended into a short triangular horn, posterior surface of carina largely glabrous. Vertex medially glabrous, laterally rugose. Antennal club yellowish gray.

Pronotum. Bordered all around, lateral margins serrate and setose, front angles sharp and pointing outward, hind corners obliquely merging into base; surface unevenly punctate, more coarsely on disc, spaces between punctures equal to or greater than puncture diameters, center of disc and midlateral areas largely glabrous; sagittal glabrous line narrow, confined to posterior half of length, does not reach medial lobe of base.

Scutellum . Exposed, small, triangular.

Elytra. With intervals convex but not sharply crested, sparsely punctate, punctures shallow, mediumsized, scattered, spaces between them range from two to ten puncture diameters; striae punctate densely, punctures as large as those on intervals. First interval narrower than others, seventh interval widest and flattest; humeri confined to sixth interval.

Pygidium . Semilunar, bordered all around, distinctly but shallowly punctate only in basal half, apical half glabrous.

Venter. Anterior process of metasternum lunate, keeled, black and impunctate, lateral of process surface finely granulorugose; hind part of metasternal plate sparsely punctate. Abdominal ventrites I–IV narrower medially than laterally and very sparsely punctate, ventrite V wider medially than laterally and more densely punctate. Entire venter devoid of setae and hairs, all hairs issue from anterior and posterior rows of punctures on legs.

Legs. Protibia with last tooth half as long as first tooth, spaces between teeth equal and finely serrate, coarser serration continues to proximal end of tibia; medial margin granulate and hirsute throughout length; both dorsal and ventral surfaces finely punctate, ventral surface more densely; dorsomedial and ventromedial carinae present throughout length, neither of them branches into bases of teeth. Mesotibia with one spur and without transverse carinae, metatibia with two transverse carinae.

Comparison. Although the specimen lacks only the distal metatarsomeres, it is a fragile empty shell glued to the pin and due to its uniqueness can be sexed only through the pygidium . Aedeagus was not found, and the shape of the last abdominal ventrite indicates that in all likelihood it is a female. Of the bicolored species, S. namibensis sp. n. ( Fig. 17–20 ) is somewhat reminiscent of S. fragilis sp. n., though S. namibensis has much darker and reddish elytra with more convex intervals, black venter, only a feeble frontal carina, protibia with a very short to rudimental last tooth, and mesotibia with two spurs and transverse carinae. In conclusion, S. fragilis sp. n. does not appear to be particularly close to any other Scarabaeolus species.

Figures

Figures 25–32. Scarabaeus (Scarabaeolus) spp. 25–28) Scarabaeus (Scarabaeolus) fragilis sp. n., HTf, 12.5 mm. 25) Dorsal habitus. 26) Ventral habitus. 27) Head leveled horizontal. 28) Locality label. 29–32) Scarabaeus (Scarabaeolus) rugosipennis sp. n., HT, 12.5 mm. 29) Dorsal habitus. 30) Ventral habitus. 31) Head leveled horizontal. 32) Locality label.

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.