Browsing by Subject "Ficus"

Now showing 1 - 4 of 4
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    Open Access
    Codivergence and multiple host species use by fig wasp populations of the Ficus pollination mutualism
    (BioMed Central Ltd, 2012) McLeish, Michael; van Noort, Simon
    BACKGROUND:The interaction between insects and plants takes myriad forms in the generation of spectacular diversity. In this association a species host range is fundamental and often measured using an estimate of phylogenetic concordance between species. Pollinating fig wasps display extreme host species specificity, but the intraspecific variation in empirical accounts of host affiliation has previously been underestimated. In this investigation, lineage delimitation and codiversification tests are used to generate and discuss hypotheses elucidating on pollinating fig wasp associations with Ficus. RESULTS: Statistical parsimony and AMOVA revealed deep divergences at the COI locus within several pollinating fig wasp species that persist on the same host Ficus species. Changes in branching patterns estimated using the generalized mixed Yule coalescent test indicated lineage duplication on the same Ficus species. Conversely, Elisabethiella and Alfonsiella fig wasp species are able to reproduce on multiple, but closely related host fig species. Tree reconciliation tests indicate significant codiversification as well as significant incongruence between fig wasp and Ficus phylogenies. CONCLUSIONS: The findings demonstrate more relaxed pollinating fig wasp host specificity than previously appreciated. Evolutionarily conservative host associations have been tempered by horizontal transfer and lineage duplication among closely related Ficus species. Independent and asynchronistic diversification of pollinating fig wasps is best explained by a combination of both sympatric and allopatric models of speciation. Pollinator host preference constraints permit reproduction on closely related Ficus species, but uncertainty of the frequency and duration of these associations requires better resolution.
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    Open Access
    Host-plant species conservatism and ecology of a parasitoid fig wasp genus (Chalcidoidea; Sycoryctinae; Arachonia)
    (Public Library of Science, 2012) McLeish, Michael J; Beukman, Gary; van Noort, Simon; Wossler, Theresa C
    Parasitoid diversity in terrestrial ecosystems is enormous. However, ecological processes underpinning their evolutionary diversification in association with other trophic groups are still unclear. Specialisation and interdependencies among chalcid wasps that reproduce on Ficus presents an opportunity to investigate the ecology of a multi-trophic system that includes parasitoids. Here we estimate the host-plant species specificity of a parasitoid fig wasp genus that attacks the galls of non-pollinating pteromalid and pollinating agaonid fig wasps. We discuss the interactions between parasitoids and the Ficus species present in a forest patch of Uganda in context with populations in Southern Africa. Haplotype networks are inferred to examine intraspecific mitochondrial DNA divergences and phylogenetic approaches used to infer putative species relationships. Taxonomic appraisal and putative species delimitation by molecular and morphological techniques are compared. Results demonstrate that a parasitoid fig wasp population is able to reproduce on at least four Ficus species present in a patch. This suggests that parasitoid fig wasps have relatively broad host- Ficus species ranges compared to fig wasps that oviposit internally. Parasitoid fig wasps did not recruit on all available host plants present in the forest census area and suggests an important ecological consequence in mitigating fitness trade-offs between pollinator and Ficus reproduction. The extent to which parasitoid fig wasps exert influence on the pollination mutualism must consider the fitness consequences imposed by the ability to interact with phenotypes of multiple Ficus and fig wasps species, but not equally across space and time.
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    A multilocus phylogeny of the world Sycoecinae fig wasps (Chalcidoidea: Pteromalidae)
    (Public Library of Science, 2013) Cruaud, Astrid; Underhill, Jenny G; Huguin, Maïlis; Genson, Gwenaëlle; Jabbour-Zahab, Roula; Tolley, Krystal A; Rasplus, Jean-Yves; van Noort, Simon
    The Sycoecinae is one of five chalcid subfamilies of fig wasps that are mostly dependent on Ficus inflorescences for reproduction. Here, we analysed two mitochondrial ( COI , Cyt b ) and four nuclear genes (ITS2, EF-1α, RpL27a, mago nashi ) from a worldwide sample of 56 sycoecine species. Various alignment and partitioning strategies were used to test the stability of major clades. All topologies estimated using maximum likelihood and Bayesian methods were similar and well resolved but did not support the existing classification. A high degree of morphological convergence was highlighted and several species appeared best described as species complexes. We therefore proposed a new classification for the subfamily. Our analyses revealed several cases of probable speciation on the same host trees (up to 8 closely related species on one single tree of F. sumatrana ), which raises the question of how resource partitioning occurs to avoid competitive exclusion. Comparisons of our results with fig phylogenies showed that, despite sycoecines being internally ovipositing wasps host-switches are common incidents in their evolutionary history. Finally, by studying the evolutionary properties of the markers we used and profiling their phylogenetic informativeness, we predicted their utility for resolving phylogenetic relationships of Chalcidoidea at various taxonomic levels.
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    Sneaky African fig wasps that oviposit through holes drilled by other species
    (2009) Compton, Stephen G; Van Noort, Simon; McLeish, Michael; Deeble, Mark; Stone, Victoria
    Watshamiella Wiebes species (Hymenoptera: Chalcidoidea: Pteromalidae: Sycoryctinae) were observed to engage, monitor and subsequently use oviposition holes made by other parasitoid fig wasp genera (Apocrypta Coquerel and Sycoryctes Mayr) to oviposit into host figs (Moraceae, Ficus) through the fig wall. They may be inquilines, klepto-parasitoids, or hyper-parasitoids; however, further biological investigations of larval diet are required to establish their life history strategy. Watshamiella species are morphologically robust, with enlarged fore femora and tibia, and aggressively interact with other fig wasps and ants. Our observations contribute towards unravelling the complex suite of behavioural adaptations and interactions involved in the community ecology of the obligate mutualism that exists between fig wasps and their host figs.