Evolution of the parasitic wasp subfamily Rogadinae (Braconidae): phylogeny and evolution of lepidopteran host ranges and mummy characteristics.

BACKGROUND: The braconid subfamily Rogadinae is a large, cosmopolitan group of endoparasitoid wasps characterised by 'mummifying' their lepidopteran host larvae, from which the adult subsequently emerges. Rogadines attack a variety of both macro- and microlepidopteran taxa, although the speciose genus Aleiodes almost exclusively attacks macrolepidopterans. Here, we investigate the phylogenetic history of the Rogadinae, revise their higher-level classification and assess the evolution of their host ranges and mummy types. We also assess the divergence times within the subfamily and discuss the reasons for the extraordinary evolutionary diversification of Aleiodes. RESULTS: Our Bayesian analyses weakly support the monophyly of the subfamily. A clade comprising all Aleiodes species and some other taxa is not nested within the tribe Rogadini as previously supposed, but instead is recovered as sister to the Yeliconini, with the remaining Rogadini genera being recovered as sister to the Stiropiini. The Rogadinae is estimated to have originated during the mid to late Eocene, 36.1-51.62 MYA. Molecular dating gives a more recent origin for the Aleiodes clade (17.98-41.76 MYA) compared to the origins proposed for two of its principal lepidopteran host groups (Noctuidae: 60.7-113.4 MYA; Geometridae 48-62 MYA). The Bayesian ancestral reconstruction of the emergence habits from the mummified hosts weakly recovered an anterior emergence as the ancestral condition for the subfamily. Producing a hard mummy has evolved at various times independently, though most of the species with this biology belong to the Aleiodes clade. CONCLUSION: Based on our results, we erect the tribe Aleiodini nov. to include Aleiodes and Heterogamus stat. rev. Cordylorhogas, Pholichora and Hemigyroneuron are synonymised with Aleiodes. The molecular dating of clades and the ancestral reconstruction of host ranges support the hypothesis that radiation within Aleiodes s. s. was due to host recruitment leading to host range expansion followed by speciation, and not to parasitoid-host coevolution. Within the Rogadinae, variation in the site of emergence from the mummified host probably evolved as a consequence of the mummy's site and mode of formation, and the extent of mummy tanning/hardness to the degree of protection needed in relation to the cost of providing it.

Systematics of the cyclostome subfamilies of braconid parasitic wasps (Hymenoptera: Ichneumonoidea): a simultaneous molecular and morphological Bayesian approach.

Phylogenetic relationships among 95 genera collectively representing 17 of the 18 currently recognized cyclostome braconid wasp subfamilies were investigated based on DNA sequence fragments of the mitochondrial COI and the nuclear 28S rDNA genes, in addition to morphological data. The treatment of sequence length variation of the 28S partition was explored by either excluding ambiguously aligned regions and indel information (28SN) or recoding them (28SA) using the 'fragment-level' alignment method with a modified coding approach. Bayesian MCMC analyses were performed for the separate and combined data sets and a maximum parsimony analysis was also carried out for the simultaneous molecular and morphological data sets. There was a significant incongruence between the two genes and between 28S and morphology, but not for morphology and COI. Different analyses with the 28SA data matrix resulted in topologies that were generally similar to the ones from the 28SN matrix; however, the former topologies recovered a higher number of significantly supported clades and had a higher mean Bayesian posterior probability, thus supporting the inclusion of information from ambiguously aligned regions and indel events in phylogenetic analyses where possible. Based on the significantly supported clades obtained from the simultaneous molecular and morphological analyses, we propose that a total of 17 subfamilies should be recognized within the cyclostome group. The subfamilial placements of several problematic cyclostome genera were also established.