Limits...
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.


Geographical distribution of C. sesamiae samples in sub-Saharan East Africa. Lineages 1, 2, and 3 are lineages defined by the phylogenetic analysis (Fig. 1).
© Copyright Policy - open-access
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC4561570&req=5

fig02: Geographical distribution of C. sesamiae samples in sub-Saharan East Africa. Lineages 1, 2, and 3 are lineages defined by the phylogenetic analysis (Fig. 1).

Mentions: Geographically, all samples were collected in the eastern part of C. sesamiae's range (Fig. 2), which covers sub-Saharan Africa from Cameroon, east toward the Indian Ocean, and from Eritrea, south toward the Republic of South Africa (Polaszek and Walker 1991). Although all three lineages were found in Kenya, sometimes in close proximity, distributions of lineage 1 and 3 were different. The samples in lineage 1 were found in 12 sites distributed in west Kenya, Uganda, Ethiopia, Erytrea, and Tanzania. With the exception of the Tanzanian site, these sites were located mostly north and west of samples in lineage 3, which were found in 16 sites distributed in south Kenya, Tanzania, Zanzibar, and Mozambic. One of this site (Ruiru, central Kenya) hosted samples from lineage 1 and 3. Samples in lineage 2 were found in fewer locations (8) distributed in south and west Kenya, close to lineage 1 and 3 sites, and in Ethiopia, close to lineage 1 site.


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)

Geographical distribution of C. sesamiae samples in sub-Saharan East Africa. Lineages 1, 2, and 3 are lineages defined by the phylogenetic analysis (Fig. 1).
© Copyright Policy - open-access
Related In: Results  -  Collection

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

fig02: Geographical distribution of C. sesamiae samples in sub-Saharan East Africa. Lineages 1, 2, and 3 are lineages defined by the phylogenetic analysis (Fig. 1).
Mentions: Geographically, all samples were collected in the eastern part of C. sesamiae's range (Fig. 2), which covers sub-Saharan Africa from Cameroon, east toward the Indian Ocean, and from Eritrea, south toward the Republic of South Africa (Polaszek and Walker 1991). Although all three lineages were found in Kenya, sometimes in close proximity, distributions of lineage 1 and 3 were different. The samples in lineage 1 were found in 12 sites distributed in west Kenya, Uganda, Ethiopia, Erytrea, and Tanzania. With the exception of the Tanzanian site, these sites were located mostly north and west of samples in lineage 3, which were found in 16 sites distributed in south Kenya, Tanzania, Zanzibar, and Mozambic. One of this site (Ruiru, central Kenya) hosted samples from lineage 1 and 3. Samples in lineage 2 were found in fewer locations (8) distributed in south and west Kenya, close to lineage 1 and 3 sites, and in Ethiopia, close to lineage 1 site.

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.