Phylogenetic Relationships among European Polistes and the Evolution of Social Parasitism (Hymenoptera: Vespidae, Polistinae)

Cladistic analysis of the European species ofPolistes is used to investigate the evolution .of social parasitism in the genus. The three species of social parasites (formerly the genus Sulcopolistes) are all inquilines: lacking a worker caste, and dependent on uSUIping the colony of a host species to obtain a worker force. El:vlERY'S Rule states that social parasites are more closely related to their hosts than to any other species. Previously published allozyme (CARPENTER et aI., 1993) and mtDNA (CHOUDHARY et aI., 1994) data did not support this hypothesis, but did not resolve relationships among the species of social parasites. Morphological characters are adduced which resolve the phylogenetic relationships among these three species, and the combination of the morphological and molecular data sets largely resolves the relationships among all nine European species. Cladistic optimization of traits associated with social parasitism on the resulting cladogram shows: (1) El:vlERy's'Rule is rejected; (2) the scenario proposed by TAYLOR (1939) for the evolution of social parasitism is not supported either. The predatory behavior of the inquiline P. atn"mandibularis, with separate "supply" and "nursery" nests, is evidently secondary, as .. is its initially passive invasion behavior. La phylogenie des Polistes d'Europe et revolution du parasitisme social (Hymenoptera: Vespidae, Polistinae) L'analyse cladistique des especes de Polistes europeennes est utilisee pour etudier l'evolution du parasitisme social dans Ie geme. Les trois especes de parasites sociaux (autrefois Ie genre Sulcopolistes) sont toutes « inquilines» : elles n'ont pas de caste ouvriere et s'approprient celle de la colonie d'une espece hOte. Le regIe d'El:vlERY afIirme que les especes de parasites sociaux sont plus proches parents de leurs hOtes que de toute autre espece. Des analyses basees sur les allozymes (CARPENTER et aI., 1993) et l'ADN mitochondrial (CHOUDHARY et al., 1994) n'ont pas confirme cette hypothese, mais n'ont pas resolu non plus les relations entre les especes parasites. L'addition de caracteres morphologiques et la combinaison des donnees morphologiques et moleculaires ont permis de resoudre respectivement 1es relations phylogenetiques entre ces trois especes, et entre les neuf especes europeennes. L'optimisation sur Ie cladogranune de traits associes au parasitisme social montre que : (1) Ie regIe d'El:vlERY est refutee ; (2) Ie scenario d'evolution du parasitisme social propose par TAYLOR (1939) est egalement refute. Le comportement predateur de l'inquiline P. atn"mandibulan's, qui maintient des nids separes pour les provisions et pour Ie couvain, est al'evidence secondaire, de meme que son comportement d'invasion initiale passive. CARPENTER, J. M., 1997. Phylogenetic relationships among europeanPolistes and the evolution of social parasitism (Hymenoptera: Vespidae; Polistinae). In: GRANDCOLAS, P. (ed.), The Origin of Biodiversity in fusects: Phylogenetic Tests of Evolutionary Scenarios. Mem. Mus. natn. Hist. nat., 173: 135-161. Paris ISBN: 2-85653-508-9. 136 1. M. CARPENTER: EVOLUTION OF SOCIAL PARASITISM INPOLISTES