Distribution and phylogeny of Wolbachia inducing thelytoky in Rhoditini and 'Aylacini' (Hymenoptera: Cynipidae).

Wolbachia are endosymbiotic bacteria responsible for thelytoky in several parasitoid hymenopteran genera. After finding these micro-organisms in some populations of Diplolepis spinosissimae (Hymenoptera: Cynipidae) where they are responsible for thelytoky through gamete duplication, we searched for Wolbachia spp. using specific PCR primers in nineteen other species of the Rhoditini tribe (rose gallwasps) and eight species of the 'Aylacini' tribe (gallwasps associated with herbaceous plants). Wolbachia were found in twelve Rhoditini species and four 'Aylacini' species. The most infected species have very few males (spanandry) and the thelytoky of infected species/arrhenotoky of uninfected species is confirmed by previous research based on the sex of the offspring of virgin females. Phylogenetic analyses based on the partial Wolbachia ftsZ gene sequences indicate that some strains associated with closely related gallwasps are phylogenetically distant, suggesting that cynipids have been affected by several infection events. In contrast, the five infected European species of Diplolepis harbour the same strain of Wolbachia.

Molecular phylogeny of the Ceratosolen species pollinating Ficus of the subgenus Sycomorus sensu stricto: biogeographical history and origins of the species-specificity breakdown cases.

The 14 species of Ficus of the subgenus Sycomorus (Moraceae) are invariably pollinated by Ceratosolen species (Hym. Chalcidoidea), which in turn reproduce in the fig florets. They are distributed mostly in continental Africa, Madagascar, and the Mascarene and Comoro Islands, but 1 species extends its geographical range all over the Oriental region. Fig-pollinator relationships are usually strictly species specific, but exceptions to the 'one-to-one' rule occur within the group we studied. In order to understand both the biogeographical history of the Ceratosolen species associated with Ficus of the subgenus Sycomorus and the origins of the specificity breakdown cases, we have used cytochrome b sequences to reconstruct a phylogeny of the fig wasps. The results show that the pollinators from the Malagasy region and those from continental Africa form two distinct clades, which probably diverged after the crossing of the Mozambique Channel by an ancestral population. The Oriental wasp species show strong affinities with the African species. The two species-specificity exceptions are due to different evolutionary events. The occurrence of the two West African pollinators associated with F. sur can be explained by successive speciation events of the mutualistic partner without plant radiation. In contrast, we hypothesize that C. galili shifted by horizontal transfer from an unknown, presumably extinct, Ficus species to F. sycomorus after this native Malagasy fig species colonized Africa.

Molecular phylogeny of fig wasps Agaonidae are not monophyletic.

According to the present classification, the family Agaonidae contains all fig pollinators as well as five subfamilies of non-pollinating fig wasps. The molecular phylogeny of the family was reconstructed using partial sequences of the 28S rRNA (D1 and D2 domains). Our results show that the family Agaonidae is not monophyletic. As a consequence, we restrict the famiy to the pollinator clade, and assign the non-pollinating subfamilies to various chalcid families. Sycoecinae, Otitesellinae and Sycoryctinae are included in Pteromalidae, whereas Sycophaginae and Epichrysomallinae are left unclassified and will require more in-depth morphological studies. Moreover, we proved that the fig pollination syndrome evolved only once, early in group history. The resource due to the fig-pollinator mutualism has secondarily been colonized independently by different Chalcid lineages.