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Ongoing ecological speciation in Cotesia sesamiae, a biological control agent of cereal stem borers.

Kaiser L, Le Ru BP, Kaoula F, Paillusson C, Capdevielle-Dulac C, Obonyo JO, Herniou EA, Jancek S, Branca A, Calatayud PA, Silvain JF, Dupas S - Evol Appl (2015)

Bottom Line: To develop efficient and safe biological control, we need to reliably identify natural enemy species, determine their host range, and understand the mechanisms that drive host range evolution.We found that one highly supported lineage showed all the hallmarks of a cryptic species.It is associated with one host insect, Sesamia nonagrioides, and is reproductively isolated from the other two lineages by pre- and postmating barriers.

View Article: PubMed Central - PubMed

Affiliation: Laboratoire Evolution, Génomes, Comportement et Ecologie, UMR CNRS-Univ. Paris-Sud-IRD, Univ. Paris-Saclay Gif-sur-Yvette Cedex, France ; INRA, UMR 1392, Institut d'Ecologie et des Sciences de l'Environnement de Paris Paris, France.

ABSTRACT
To develop efficient and safe biological control, we need to reliably identify natural enemy species, determine their host range, and understand the mechanisms that drive host range evolution. We investigated these points in Cotesia sesamiae, an African parasitic wasp of cereal stem borers. Phylogenetic analyses of 74 individual wasps, based on six mitochondrial and nuclear genes, revealed three lineages. We then investigated the ecological status (host plant and host insect ranges in the field, and host insect suitability tests) and the biological status (cross-mating tests) of the three lineages. We found that one highly supported lineage showed all the hallmarks of a cryptic species. It is associated with one host insect, Sesamia nonagrioides, and is reproductively isolated from the other two lineages by pre- and postmating barriers. The other two lineages had a more variable phylogenetic support, depending on the set of genes; they exhibited an overlapping and diversified range of host species and are not reproductively isolated from one another. We discuss the ecological conditions and mechanisms that likely generated this ongoing speciation and the relevance of this new specialist taxon in the genus Cotesia for biological control.

No MeSH data available.


Relative abundance of stem borer–plant associations present in the sites where C. sesamiae samples were found. Sites hosting C. sesamiae from the same lineage were pooled for the analysis. Arrows indicate on which association C. sesamiae samples were found, and colors correspond to the lineage.
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fig03: Relative abundance of stem borer–plant associations present in the sites where C. sesamiae samples were found. Sites hosting C. sesamiae from the same lineage were pooled for the analysis. Arrows indicate on which association C. sesamiae samples were found, and colors correspond to the lineage.

Mentions: The family and species status of the host insects and the host plants were reported on the phylogenetic tree. For a better understanding of the observed differences in host range between C. sesamiae lineages, we characterized the diversity of host insects and plants in the sampled sites, by analyzing the relative abundance of stem borer species collected on the different plant tribes for each pool of sites where specimens of a given lineage of C. sesamiae had been collected (Fig. 3). This formed three pools of sites, one per lineage (over the 37 sampled sites, only one hosted C. sesamiae samples from two lineages).


Ongoing ecological speciation in Cotesia sesamiae, a biological control agent of cereal stem borers.

Kaiser L, Le Ru BP, Kaoula F, Paillusson C, Capdevielle-Dulac C, Obonyo JO, Herniou EA, Jancek S, Branca A, Calatayud PA, Silvain JF, Dupas S - Evol Appl (2015)

Relative abundance of stem borer–plant associations present in the sites where C. sesamiae samples were found. Sites hosting C. sesamiae from the same lineage were pooled for the analysis. Arrows indicate on which association C. sesamiae samples were found, and colors correspond to the lineage.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4561570&req=5

fig03: Relative abundance of stem borer–plant associations present in the sites where C. sesamiae samples were found. Sites hosting C. sesamiae from the same lineage were pooled for the analysis. Arrows indicate on which association C. sesamiae samples were found, and colors correspond to the lineage.
Mentions: The family and species status of the host insects and the host plants were reported on the phylogenetic tree. For a better understanding of the observed differences in host range between C. sesamiae lineages, we characterized the diversity of host insects and plants in the sampled sites, by analyzing the relative abundance of stem borer species collected on the different plant tribes for each pool of sites where specimens of a given lineage of C. sesamiae had been collected (Fig. 3). This formed three pools of sites, one per lineage (over the 37 sampled sites, only one hosted C. sesamiae samples from two lineages).

Bottom Line: To develop efficient and safe biological control, we need to reliably identify natural enemy species, determine their host range, and understand the mechanisms that drive host range evolution.We found that one highly supported lineage showed all the hallmarks of a cryptic species.It is associated with one host insect, Sesamia nonagrioides, and is reproductively isolated from the other two lineages by pre- and postmating barriers.

View Article: PubMed Central - PubMed

Affiliation: Laboratoire Evolution, Génomes, Comportement et Ecologie, UMR CNRS-Univ. Paris-Sud-IRD, Univ. Paris-Saclay Gif-sur-Yvette Cedex, France ; INRA, UMR 1392, Institut d'Ecologie et des Sciences de l'Environnement de Paris Paris, France.

ABSTRACT
To develop efficient and safe biological control, we need to reliably identify natural enemy species, determine their host range, and understand the mechanisms that drive host range evolution. We investigated these points in Cotesia sesamiae, an African parasitic wasp of cereal stem borers. Phylogenetic analyses of 74 individual wasps, based on six mitochondrial and nuclear genes, revealed three lineages. We then investigated the ecological status (host plant and host insect ranges in the field, and host insect suitability tests) and the biological status (cross-mating tests) of the three lineages. We found that one highly supported lineage showed all the hallmarks of a cryptic species. It is associated with one host insect, Sesamia nonagrioides, and is reproductively isolated from the other two lineages by pre- and postmating barriers. The other two lineages had a more variable phylogenetic support, depending on the set of genes; they exhibited an overlapping and diversified range of host species and are not reproductively isolated from one another. We discuss the ecological conditions and mechanisms that likely generated this ongoing speciation and the relevance of this new specialist taxon in the genus Cotesia for biological control.

No MeSH data available.