Systematics of the subtribe Scarabaeina Latreille, 1802 (Coleoptera :Scarabaeidae).

Abstract

The taxonomic history of Scarabaeini, and the morphological and biological features characteristic of members of this tribe, is discussed. Each subtribe of Scarabaeini is briefly reviewed, and a key to the subtribes is provided. The subtribe Scarabaeina is more fully discussed prior to its sys= tematic assessment. A new flightless species, Scarabaeus scholtzi spec. nov. is described, and the taxonomic position of the flightless species within Scarabaeina is evaluated. It is concluded that these species do not represent one or more monophyletic groups, but are the consequence of adaptation by species of Scarabaeus. to localised conditions of extreme aridity and, possibly, windi= ness. The genera Pachysoma M'Leay and Neomnematium Janssens, in which the flightless species are contained, are consequently synonymised with Scarabaeus L. The validity of the genera Mnematidium Ritsema, Neateuchus Gillet and Madateuchus Paulian is assessed. As no definitive autopomorph could be found for each of these genera, they are synonymised with Scarabaeus L. The genus Pachylomera Kirby is emended to Pachylomerus Bertoloni. The genera of Scarabaeina, as redefined in this work, are reviewed and a key to these genera is provided. A phylogeny and classification of the genera is proposed, based largely on cladistic principles. The thesis is illustrated with 169 photographs, drawings and maps.