Phoberus caffer (Harold, 1872)

Strümpher, Werner P. & Scholtz, Clarke H., 2019, A new Phoberus MacLeay species (Coleoptera: Scarabaeoidea: Trogidae) from the Maloti-Drakensberg Mountains of southern Africa and the Phoberus caffer species group reviewed, Zootaxa 4674 (5), pp. 551-563 : 552-553

Phoberus caffer species group

The three species treated here are grouped together on the basis of the overall shape and structure of the male genitalia, which are identical for all three members ( Figs. 3 , 7 , 11 , 17 ) but distinctly different from those of all other species of Phoberus . Male genitalic similarity is unusual among Phoberus species, since shape and associated aedeagal characters are usually unique to each species (also see Strümpher & Scholtz 2017). The invariable male genitalia may suggest relatively recent geographic and genetic separation of the species of this group, particularly of the two isolated montane species derived from a widespread caffer -like ancestor. The fact that P. lilianae populations occur on two widely separated mountains without discernible signs of speciation between them might provide additional support for this suggestion. Future molecular studies of these populations may, however, suggest alternative hypotheses. The members of the Phoberus caffer species group are further characterised by their relatively rounded pronotal discal area, which bears a shallow median depression, and by smooth and round (sometimes oval) elytral tubercles. Despite their overall similarity, and lack of diagnostic male genital morphology, the three members can be reliably separated by the key provided below. Distinguishing members of the caffer species group from other morphologically similar congeners (e.g. P. sulcatus (Thunberg, 1787) , P. luridus (Fabricius, 1781) , P. cyrtus ( Haaf, 1953) , P. nama (Kolbe, 1908) , P. nyansanus ( Haaf, 1953) , and P. nyassicus ( Haaf, 1953)) could prove problematic in the absence of male specimens. For accurate identifications it is, therefore, advisable to also consult Scholtz (1980) and Strümpher & Scholtz (2017).

Diagnosis of the Phoberus caffer species group. Size: Length 9.3–14.7 mm, width 5.5–8.7 mm. Colour: Black. Head: Surface punctate, punctures discrete, surface between punctures matt or shiny; clypeus triangular, apex slightly deflexed; frons low or raised and glabrous dorsally, with paired, rounded, setose ridges; antennal scape elongate, with long yellow to fulvous or black setae. Pronotum: Surface with discrete, round punctures, surface between punctures matt or shiny; pronotal sides broad; lateral margins irregular, strongly attenuated anteriorly, with fringes and tufts of yellow or black setae; discal area raised, broad, rounded; median depression shallow; median basal tubercles discrete, fused to discal area; lateral tubercles partially fused, forming a low broad ridge; tubercles and ridges with tufts of yellow or dark brown to black setae. Elytra: Humeral calli prominent; lateral margins smooth, sides broad; sutural margin raised; surface dull or shiny, with low round to oval tubercles, smooth and matt or shiny with a posterior tuft of yellow or black setae, tubercles irregularly distributed along margin; even-numbered costae prominent, with smooth round to oval tubercles, distinctly arched from the base, with a posterior tuft of yellow or black setae, tubercles either large, shiny, and widely and irregularly spaced (less numerous) or smaller, matt, and reasonably evenly spaced (more numerous); odd-numbered costae either with prominent or small round, shiny or matt black tubercles, regularly or irregularly spaced, each with a single seta; costae separated from intercostae by distinct elevated bands; intercostae with undulating depressions separated by small transverse ridges; elytral profile convex, attaining maximum height in the middle. Legs: Foretibia dorsally keeled, with small apical process; outer margin with 2 median teeth and several smaller basal teeth; inner margin with long, dense black or yellow setae; apex of foretibia bidentate (= male) or not distinctly bidentate (= female); foretibial spur as long as, or longer than, third tarsomere; mesotibia and metatibia with long, dense, black or yellow setae, 2 apical spurs on inner margin, spurs as long as, or slightly longer, than first tarsomere; tarsomeres ventrally with sparse setae; claws simple. Meta- thoracic wing: Complete. Male genitalia: See Figs. 3 , 7 , 11 , 16 .

Figures

FIGURES 1–4. Phoberus ntlenyanae Strümpher, new species, holotype. 1, dorsal habitus; 2, lateral habitus; 3, dorsal and lateral views of aedeagus; 4, holotype labels.

FIGURES 5–8. Lectotype of Trox caffer Harold, 1872, designated by Scholtz 1980: 95 (MNHN). 5, dorsal habitus; 6, lateral habitus; 7, dorsal and lateral views of aedeagus; 8, lectotype labels. Photographs by Antoine Mantilleri, copyright MNHN.

FIGURES 9–12. Phoberus caffer (Harold, 1872), specimen with indument removed (TMSA). 9, dorsal habitus; 10, lateral habitus; 11, dorsal and lateral views of aedeagus 12, labels.

FIGURES 15–18. Phoberus lilianae (Scholtz, 1980), paratype (SAMC). 14, dorsal habitus; 15, lateral habitus; 16, dorsal and lateral views of aedeagus; 17, paratype labels.