Molecular phylogeny of Cotesia Cameron, 1891 (Insecta: Hymenoptera: Braconidae: Microgastrinae) parasitoids associated with Melitaeini butterflies (Insecta: Lepidoptera: Nymphalidae: Melitaeini).

Phylogenetic relationships among Cotesia Cameron (Braconidae) species parasitising Melitaeini butterflies were examined using DNA sequence data (mitochondrial cytochrome oxidase subunit I and NADH1 dehydrogenase genes, nuclear ribosomal DNA internal transcribed spacer region) as well as 12 microsatellite loci. Molecular data were available from ostensibly six species of Cotesia from 16 host butterfly species in Europe, Asia, and North America. Analysis of the combined sequence data using both maximum parsimony and maximum likelihood revealed two distinct Cotesia clades. In one clade (C. acuminata (Reinhard); C. bignellii (Marshall)) host ranges are apparently narrow and, although Euphydryas (s. lato) is well-utilised, permeation of Melitaea (s. lato) has been slight. In the other clade (C. melitaearum (Wilkinson); C. lycophron (Nixon); C. cynthiae (Nixon)) host utilization across the Melitaeini as a whole is more extensive and the data are consistent with more recent, or active, speciation processes. Neighbour-joining trees calculated separately for the two main clades based on chord distance (DCE) of microsatellite allele frequencies were consistent with phylogenetic trees obtained from the sequence data. Our analysis strongly suggests the presence of several additional, previously unrecognised, Cotesia species parasitising this group of butterflies. Copyright 2003 Elsevier Inc.