S. Mahunka szerk.: Folia Entomologica Hungarica 52. (Budapest, 1992)

FOLIA ENTOMOLOGICA HUNGARICA ROVARTANI KÖZLEMÉNYEK LU (1991) 1992 p. 29-34 Taxonomic notes on Cyphogastra Deyrolle (Coleoptera: Buprestidae), II. The Suturalis-circle By R Holynski (Received July 15, 1988) Taxonomic notes on Cyphogastra Deyrolle (Coleoptera: Buprestidae) II. The Suturalis-circle. - The term "circle" is proposed to denote delimited group of closely related species within a subgenus. The Suturaliscircle of Cyphogastra Deyrolle is reviewed, a key is presented and the phylogenetical history reconstructed. After having reviewed (Holynski 1992) the subgenus Guamia Théry, I found myself face to face with a virtually incomprehensible jungle of forms, localities and names belonging - or, at least, attributed - to the nominate subgenus. Fortunately, as is usually the case with species in large genera, this swarm is divisible into more or less clearly definiable sections, which can be analysed one by one. The use of such a category, intermediate between species and subgenus, is frequently very convenient in taxonomical discussions, and indeed many zoologists have recourse to it. Yet some confusion comes from the surprising fact, that apperantly no appropriate technical term is available, supraspecific subdivisions of subgenus being usually referred to as either (incorrectly) superspecies or (imprecisely) group. In this situation I found it necessary to introduce the term "circle", defining it as follows: a circle is a group of closely related species, nomenclaturally informal, but otherwise having all the properties of an infrasubgeneric taxon. As such, circles must be in particular: monophyletic (but not necessarily holophyletic), i. e. all the ancestors of any member of a circle, back to - and inclusive of - the common ancestor, belonged to that circle; exhaustive, i. e. each species of a subgenus belongs to one circle or another; exclusive, i. e. a species belonging to one circle does not belong to any other; equivalent, i. e. accepted minimum of difference between - and accepted maximum of variation within - circles should be approximately equal. So defined, the category of circle, a little informal as it is, fits nevertheless very well into the system of hierarchical evolutionary classification. The Suturalis - circle is characterized by relatively flat body not or very indistinctly caudate elytra; evenly convex (with no trace of differently sculptured longitudinal sulci) elytral surface; bluish suture (or all the elytra bluish-black to black); protibia with a sharp keel along the external ridge, bordered on both sides by deep furrows; pronotal grooves irregular and/or lateroposterior elevated relief triangular. None of these features is diagnostic by itself, but together they make the circle a well-defined group and strongly support its monophyly (in evolutionary, not cladistic, sense, i. e. monophyletic group must contain all surviving or extinct progenitors of the species included, down to at least their last common ancestor, but not necessarily all the descendants of the latter).