The shield-backed katylids of Southern Africa: their taxonomy, ecology and relationships to the faunas of Australia and South America (Orthoptera : Tettigoniidae : Tettigoniinae)

Abstract

This paper reviews the shield-backed katydids (Tettigoniinae, formerly the Decticinae, see Rentz (1979, 1985) for discussion) of southern Africa. Types of all taxa, except one, have been examined and extensive generic reassignments and species' synonymies are made. The tettigoniine faunas of southern Africa, Australia, and South America are analysed and discussed. It is concluded that the faunas of South America and Australia are closer to one another than to that of southern Africa, although the three are related. They are attributed to an ancient Gondwanaland fauna which is reflected in the known distribution of the southern African genera. These are shown to be related to the North American genus Neduba and its relative Aglaothorax. Discussion of analogus structures is presented and Aglaothorax is brought out of synonymy with Neduba on the basis of morphological and cytological evidence.

Seventeen species are described, in seven genera; three genera are described as new. Arytropteris Herman is restricted to three species: A. basalis (Walker) is used for A. semiaeneus of authors. Thyreonotus semiaeneus Serville is transferred to a new genus, Alfredectes. A. excisa Peringuey is a new synonym of Arytropteris granulithorax Peringuey. A. pondo is described as a new species. Zuludectes is described to include one species, Z. modestus Peringuey, formerly in Arytropteris. Anarytropteris Uvarov includes two described species: A. fallax Uvarov and A. chirinda, sp. nov., both from Zimbabwe; four specimens are listed as potentially representing distinct species. Namaquadectes is described to include a single species, N. irroratus (Peringuey), known only from the female holotype. Ceresia includes a single species, C. pulchripes Peringuey, represented by the male holotype. Thoracistus Pictet is shown to have three distinct species-groups: the arboreus Group contains a single new species, T. arboreus; the viridifer Group contains T. viridifer (Walker) which includes Arytropteris intricata Peringuey, A. plebeia Peringuey as new synonyms; the peringueyi Group includes T. peringueyi Pictet and T. aureoportalis, T. semeniphagus, T. viridicrus, T. thyraeus, T. jambila which are all described as new. A species represented by females is noted but not described.Alfredectes, gen. nov., includes the earliest described species, Thyreonotus semiaeneus Serville, from the Cape of Good Hope; A. browni, sp. nov., is described and a single species represented by a female is listed but not described. Keys and tables are presented for all species and all taxonomically important structures are illustrated. Karyotypes are presented for Thoracistus aureoportalis, T. semeniphagus, T. viridicrus, T. viridifer.