Description of a new monospecific genus of South African Trichiina, with a key to the related genera (Coleoptera: Scarabaeidae)

Abstract. A new monospecific genus, Pseudostegopterus gen. nov., endemic to the northwestern region of South Africa, is erected. The type species is described as Pseudospegopterus melonthinoides sp. nov. and is currently known only from male specimens. A provisional dichotomic key of the African Trichiina genera is also provided, in order to facilitate the identification of male specimens to the genus level.


Introduction
The number of described Trichiina species (sensu Smith et al. 2006) endemic to South Africa has increased substantially during the last two decades (Evans 1987;Ricchiardi 1997Ricchiardi , 1998Ricchiardi , 1999Ricchiardi , 2000Ricchiardi et al. 2004Ricchiardi et al. , 2008Sipek et al. 2012;Ricchiardi & Perissinotto 2013, 2014 and currently ranges around 40. These species are grouped into nine genera, with three of them regarded as tropical intruders and represented in South Africa by one single species each. The biodiversity richness of this country is well established, but many taxa remain as yet underscribed, among them several Trichiina. While undertaking a close analysis of the specimens preserved at the Iziko South African Museum (ISAM) in Cape Town and in my private collection, I have recently identifi ed a series of eight males belonging to an undescribed species, which superfi cially resembles members of the genus Stegopterus Burmeister & Schaum, 1840. However, on closer scrutiny it is clear that a new genus is involved. Both genus and species are hereby described as Pseudostegopterus gen. nov. and P. melolonthinoides gen. et sp. nov.
The species is currently known only from the two type localities of Elands Bay and Pella Mission in the Western Cape, South Africa.
The specimen length was measured between the apex of the pygidium and the anterior margin of the pronotum. The specimen width is the maximum elytron width. The clypeus length was measured laterally, between the frontal margin and the antennal basal attachment.
Photographs were taken with a Nikon Coolpix P7700, sometimes attached to one of the eyepieces of a Wild dissecting microscope. Photographs were processed with photo stacking software (Zerene Stacker -Version 1.04 Build T201411272115, http://www.zerenesystems.com [accessed 13 Nov. 2015]). Finally, backgrounds were removed from photos using GIMP 2.8.14, in order to increase contrast.

Discussion
This work is part of a series of studies aimed at identifying and clarifying the composition and morphological relations of the exceptionally diverse South African Trichiina. The phylogenetic relationships among the Trichiina of South Africa and those occurring in other parts of the continent are yet to be investigated and in need of further species descriptions and better defi nition of the genera. As a contribution to the understanding of the morphological relationship between the South African genera of Trichiina an updated dichotomic key is here proposed.
Preliminary key to South African Trichiina genera

Diagnosis
This new genus differs from all other Trichiini genera occurring in South Africa by the following combination of diagnostic characters: 1) The eye-canthus covers about ½ of the ocular hemisphere; 2) the frons and vertex are covered with thick, long, inclined, testaceous setae; 3) the length of the pronotum is < 0.5 times that of the elytra; 4) the posterior pronotal margin does not exhibit any ridge centrally; 5) the pronotal surface is generally covered with thick, long, inclined, testaceous setae; 6) the pronotal posterior corners are obtuse; 7) the elytral apex is rounded; 8) the elytral lateral ridge is visible on the entire lateral border; 9) the elytra cover the entire pygidium, except its very apex; 10) the length of protarsal claws is 0.70-0.90 times that of the last tarsomere; 11) the mesotibia are slightly curved outwardly; 12) the metatibia exhibits two spurs; 13) the fi rst metatarsal segment is as long as the second or shorter; 14) the metatibial apex is strongly enlarged; 15) the internal corner of the metatibial apex is deprived of long spines; 16) the mesosternal process is absent; 17) the metafemur width is 0.4-0.45 times its length; 18) the males are fully winged.

Etymology
The name comes from its superfi cial resemblance to some representatives of the genus Stegopterus Burmeister & Schaum, 1840.
ANTENNAE. Brown, with three lamellae, darkening at apex, slightly curved, about 2.0 times the length of clypeus. PRONOTUM. Black, slightly shiny and rugulose, wider than long; anterior angles rounded, posterior acute, with slightly rounded tip; posterior margin without carina; surface covered with thick, long, reclining, testaceous setae.
SCUTELLUM. Black, slightly shiny, triangular, as long as wide, apex slightly rounded; covered with scattered, rounded punctures.
PROTIBIA. Brown, glabrous, shiny, with two robust teeth on external margin.
METATIBIA. Black, shiny, with apex strongly enlarged; covered with scattered, long, reddish, bristles; metatarsomeres black, twice as long as metatibia (claws included); fi rst segment about as long as second; spurs long, with apex rounded, especially on ventral one; dorsal spur 1.2 times longer than ventral and arcuate; metafemur enlarged, width 0.5 times its length.

Remarks
The female is unknown.

Type series variability
Some paratypes have darker elytra and/or scattered instead of dense setae on head and pronotum, which does not seem to represent simply wear and tear due to age.

Distribution
The single species belonging to this new genus is known from two places in the Western Cape Province. These two localities are especially relevant, as they are part of a unique biome, the fynbos, which is seriously threatened by climate change and land use.