THE GROUND BEETLE GENUS CASNOIDEA CASTELNAU - TAXONOMY, PHYLOGENY ANDZOOGEOGRAPHY (INSECTA, COLEOPTERA, CARABIDAE, ODACANTHINAE)

On the basis of morphological characters of adults, the odacanthine ge nus Casnoidea Castelnau is reviewed and a key to the species is provid ed. Of the 17 species, seven are described as new: Casnoidea celebensi s, sp. nov., from Sulawesi, C. ceylonica, sp. nov., from Sri Lanka, C. leytensis, sp. nov., from Leyte (Philippines), C. australica, sp. nov ., and C. storeyi, sp. nov., both from northern Australia, C. malickyi , sp. nov., from northern Thailand and C. brandti, sp. nov., from Boug ainville (Solomon Islands). The first five species are closely related to the widespread Oriental species C. interstitialis (Schmidt-Gobel), C. malickyi is related to the Oriental species C. nigrofasciata (Schm idt-Gobel), and C. brandti is closely related to the Papuan C. gestroi (Maindron). An Australian record of the Oriental species C. indica (T hunberg) indicates an accidental introduction. For the Australian spec ies C. puncticollis and C. thouzeti new records show more extensive ra nges than known previously. C. thouzeti (Castelnau) is also a new reco rd from New Guinea. For C. foersteri (Bouchard) a new subgenus Procasn oidea, subgen. nov., is erected because of certain aberrant and presum ably plesiomorphic external and genitalic characters present in this s pecies. On the basis of the cladistic method as proposed by Hennig, a phylogenetic and biogeographic analysis shows that Casnoidea is a youn g, highly evolved genus that probably originated in the so-called 'Sun daland'. Apart from some rather primitive species or dibasic species-g roups (C. gestroi-group, C. puncticollis, C. indica, C. thouzeti) the subgenus Casnoidea s. str. is divided into two more diverse species gr oups, namely the nigrofasciata-group with C. nigrofasciata, C. bakeri, C. bhamoensis and C. malickyi, and the interstitialis-group with C. i nterstitialis, C. ishiii, C. celebensis, C. ceylonica, C. leytensis, C . storeyi and C. australica. Both groups combine closely related speci es that apparently have been derived from the same stocks with the wid espread C. nigrofasciata and C. interstitialis, respectively, and the species have mostly rather restricted ranges at or beyond the margins of the range of the wide-ranging species. Phylogenetical and chorologi cal evidence reveals that several evolutionary events occurred within the genus and that Wallace's line was probably crossed six times indep endently in easterly direction by the gestroi-, puncricollis-, indica- and thouzeti-stocks and within the nigrofasciata- and interstitialis- groups. The Papuan and Australian subregions have been colonised by di fferent stocks and the shared species may have colonised New Guinea ra ther recently from the south. For Australia at least three independent immigrations of Casnoidea species from the Oriental region are postul ated, namely by the thouzeti-, puncticollis- and australica-storeyi-li neages.