Our study reveals deep mtDNA divergences within P. imperialis and indicates the presence of cryptic species. The data further suggest that these fig-pollinating wasps have diverged without a role for host plant shifts or corresponding fig speciation. This adds to the growing body of evidence that figs and their pollinators have not radiated simply by strict cospeciation. Recent studies of figs in sections Americana and Pharmacosycea have revealed that some wasp species are regularly associated with two fig species and that host shifts may be common. There is also support for past hybridisation of at least one pair of these fig species linked by a common wasp species. Consequently, Machado et al. [15] suggested a revised coevolutionary model involving groups of genetically well-defined wasp species coevolving with groups of genetically less well-defined (frequently hybridizing) groups of figs. Current data on Malvanthera figs and their Pleistodontes pollinators support the notion of genetically well-defined wasp species, but we have not found regular sharing of pollinator species between distinct fig species, despite frequent coexistence of multiple wasps on one fig species. In addition, the few obviously hybrid trees we know are cultivated rather than wild. However, we now need genetic studies of potentially hybridising fig species, along with continuing surveys of pollinator specificity, to assess whether this new model applies widely to figs and fig wasps. In summary, there are at least two ways – host shifting and independent wasp speciation – to evolve co-pollinators and break the 1:1 rule of host specificity.
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