Macroderes bias Olivier 1789
Creators: name: Abdalla, Ishtiag H.
name: Deschodt, Christian M.
name: Scholtz, Clarke H.
name: Sole, Catherine L.
Publisher: name: Zenodo
Year: 2018
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Coleoptera
Scarabaeidae
Macroderes
Macroderes bias

description: Macroderes bias Olivier, 1789
(Figs. 9, 28, 55, 57, 61, 66)
Scarabaeus bias Olivier, 1789: 187.
Macroderes bias: Preudhomme de Borre 1880: 8; Péringuey 1901: 299; Janssens 1939: 28; Ferreira 1969: 320; Frolov & Scholtz 2005: 376.
Macroderes pilula Sharp, 1880: 38; Frolov & Scholtz 2005: 376 (junior synonym of M. bias).
Type locality. South Africa, Graham’s Town [33°18'S 26°32'E].
Type material examined. None. Neotype designated by Frolov & Scholtz (2005) is deposited in IRSNB.
Additional material examined. 1 ♂ and 1 ♀ (AMSA): “B[aviaans] / Kloof / Jan. 1893 / MRS. G. White ”; 1 ♀ (AMSA): “TARKASTAD / ‘KELSO’ / SHEEP DROPPINGS / JAN ’62 / [32° 00' 28.35'' S 26° 16' 18.49'' E]”; 1 ♀ (AMSA): “TARKASTAD / In veld / Jan ‘62”; 1 ♀ (AMSA): “LYEDOCH / BEDFORD / COW DUNG / JAN 62 / [33° 58' 57.0''1 S 18° 46' 04.47'' E]”; 1 ♂ (SANC): “UNIONDALE / E Cape / (10 kms NE) / 4. 7. 76 / 970 m / [33° 38' 55.5'' S 23° 08' 17.52'' E] / Davis & Aschenborn // Ex Coll / CISRO / Div / Entomology / S. AFRICAN STATION // Macroderes bias (Oliver) / Frolov / det. 2003”; 1 ♂ (SANC): “ Macroderes bias ”; 1 ♂ and 1 ♀
(SANC) without locality label; 1 ♂ and 1 ♀ (AMSA): “ Grahama’s Town / 11 / 0 4 / 0 5 / [33° 19' 28.26'' S 26° 3' 7 23.93'' E] // Macroderes bias (Oliver) / Frolov / det. 2003”; 1 ♂ and 1 ♀ (AMSA): “ Cape Province / Strowan / Grahamstown / 11.IV.1969 / [33° 18' S 26° 32' E] / F.W.Gess ”; 1 ♂ (SANC): “ South Africa / Cape P / 46 Km / NW of Steytleville / 680 m / 05.v.1976 / [33° 18' 49.12'' S 24° 17' 54.55'' E] / Davis & Aschenborn // DBRU locality / 2307 / Stony sandy loam / Scrub / cattle dung // Macroderes sp”; 1 ♂ (TMSA): “ 20. X. 1922 / Dr. Brauns / Hamendoor / Camper / Macroderes bias (Oliver)? / Frolov / 2003”. 1 ♀ (TMSA): “S. Afr / Cape / Toorberg E / 1522 m / 32°. 10' S–24°. 02' E // 22.11. 2007 // E–Y: 3759 / under stones / Ruth Muller leg // TM / SOUTH AFRICA / TMSCO 9075 // Macroderes bias (Oliver) / det. Adrian Davis / 2014”; 1 ♀ (TMSA): “ SOUTH AFRICA / Cradock / Jan 1951 / [32° 10' 51.50'' S 25° 39' 03.57'' E] / G. S. Bosch // Macroderes bias (Oliver)? / Det. Frolov / 2003”; 1 ♀ (TMSA): “S. Afr / Cape Prov / Addo park / R. Wolmarans // 16–20. 12. 1996 / PJ / 1–6 / [33 28 53.91 S 25 43 47.23 E] // Macroderes bias (Olivier) / det. A. Frolov / 2003”; 1 ♂ (SAMC): “ Koeberg [un-traceable word] leg // Macroderes bias / Macroderes bias (Olivier) / Frolov & Scholtz / 2003”; 2 ♂♂ and 2 ♀♀ (SAMC): “ Grahamstown / 11.VI.1905 / [33° 19' 28.26'' S 26° 3' 7 23.93'' E] / Macroderes bias (Olivier) / Frolov & Scholtz / 2003”.
Size range. Males length: 9.2–11.3 mm, width: 6.0– 8.2 mm; females length: 8.2–12.5 mm, width: 6.3–8.3 mm.
Differential diagnosis. Due to its flatter intervals of elytra (Figs. 9, 66), M. bias is close to M. mutilans and M. fornicatus, nevertheless, it can be distinguished from both species by the closeness of stria 9 and stria 10 (Fig. 55) and from M. mutilans in that the lateral border of pronotum is punctate (Fig. 57) and the long sclerite of the internal sac (Fig. 28).
Habitat and distribution. Compared to the other species in the group this species has a wide distribution range in the Eastern Cape Province (Fig. 2). The range stretches over many bioregions encompassing the Eastern Fynbos-Renosterveld, Upper and Lower Karoo Bioregions and into the grassland Biome.
Remarks. Macroderes bias is the only species known from the Eastern Cape Province. Although the material studied have shown common characteristics such as the same even rounded shape of pronotum punctures, punctate lateral border of pronotum and the proximity of striae 9 and 10, there are distinct variations in the male pronotal shapes and elytral punctuation. Some males show strong antero-lateral excavation on the pronotum combined with an impunctate midline on the top, while others have a slight depression antero-laterally with their pronotum evenly punctuated. Also the elytral interstriae in some males are flat and intensely punctuated while in others elevated medially and between the punctures. It seems that this species is one of a complex of species endemic to the region. Due to its rarity in collections it is difficult to judge these differential diagnostic characters since there are no new records of the species post the last study by Frolov & Scholtz (2005); with exception of a single female specimen collected in 2007 from Toorberg area which is not adequate to assign specific characters for species identification. In addition to this, fresh material is needed for molecular analysis which would allow us to infer phylogenetic relationships of the different specimens.
description: Published as part of Abdalla, Ishtiag H., Deschodt, Christian M., Scholtz, Clarke H. & Sole, Catherine L., 2018, An update to the taxonomy of the genus Macroderes Westwood 1842 (Coleoptera: Scarabaeidae: Scarabaeinae) with descriptions of new species from South Africa, pp. 41-75 in Zootaxa 4504 (1) on pages 45-47, DOI: 10.11646/zootaxa.4504.1.3, http://zenodo.org/record/2606164