Description of a new brachypterous scarab species, Orphnus brevialatus (Coleoptera: Scarabaeidae: Orphninae) from East Africa, with notes on flightlessness in the orphnines

Abstract

A new brachypterous species of the scarab beetle genus Orphnus Macleay, 1819, O. (O.) brevialatus Frolov & Akhmetova, new species, is described from Kipengere Range (Livingstone Mountains), Tanzania. The new species differs from other flightless Orphnus species occurring in East Africa in having a well-developed pronotal armature with two long, acute lateral processes. In the shape of the head, pronotum, and male genitalia it is similar to O. compactilis Quedenfeldt, 1882, but differs from it, in addition to the reduced wings and shorter body, in the shape of the endophallic armature. Flightlessness is rather common among the orphnines: 56 orphnine species out of 235 have the wings reduced to different degree making them incapable of flight, although this is a preliminary minimum figure. Flightless species are found in Hybalus Dejean, 1833, Chaetonyx Schaum, 1862, Orphnus Macleay, Hybaloides Quedenfeldt, 1884, Aegidium Westwood, 1845 and Stenosternus Karsch, 1881. All regional orphnine faunas except for Indo-Malayan and Madagascan include flightless species, although flightlessness is more common in African taxa.