Revision of the Western Cape endemic genus Stegopterus Burmeister & Schaum, 1840 (Coleoptera, Scarabaeidae, Cetoniinae, Trichiini)

Stegopterus Burmeister & Schaum, 1840 is a Trichiini genus endemic to the Western Cape Province of South Africa. Until now, it has been regarded as comprising only four species, namely S. vittatus (Fabricius, 1775), S. suturalis (Gory & Percheron, 1833), S. septus Burmeister & Schaum, 1840 and S. obesus Burmeister, 1842. Our study of historical specimens housed in museums and private collections, along with new specimens collected recently, has revealed that there are at least 15 species in this genus of which 11 are new, with S. obesus relegated to incertae sedis (see updated species list below). What is most interesting is that the genus has radiated within a rather restricted region, between the South and West coasts and the Cape Fold Mountains (CFM). This reflects a typical Fynbos distribution, similar to that already described for other insect groups. On the basis of synapomorphy, Stegopterus has now been subdivided into two species groups, namely “ vittatus ” and “ septus .” In this work, 11 new species are described, diagnosed and illustrated, and their geographic distributions are mapped: Stegopterus agulhas sp. nov. , S. cochraneae sp. nov. , S. endroedyi sp. nov. , S. fuscus sp. nov. , S. hexrivieri sp. nov. , S. kromrivieri sp. nov. , S. lamellus sp. nov. , S. langebergicus sp. nov. , S. pallidulus sp. nov. , S. paardebergi sp. nov. , S. rotundiceps sp. nov . A key for accurately identifying species of Stegopterus is provided. Lectotypes are designated for the following species: S. septus Burmeister & Schaum, 1840, Trichius suturalis Gory & Percheron, 1833 (now S. suturalis ) and Cetonia vittata Fabricius, 1775 (now S. vittatus ).