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3 resultados encontrados para: AUTOR: Poteaux, Chantal
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1.
- Artículo con arbitraje
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Ant parasitoidism has been reported in seven of the 26 recognized species of the mite genus Macrodinychus (Machrodynichidae). Macrodynichus sellnicki, previously reported as a parasitoid of the invasive ant Nylanderia fulva in Colombia, is now reported, in the same region, as attacking a native host, Ectatomma sp. 2 (E. ruidum complex). The mite develops within the protective silk cocoon of an Ectatomma pupa and waits for the emergence of the young ant before leaving the cocoon, unmolested. Overall nest prevalence was relatively high (34.6% of the 52 nests containing cocoons) but pupae prevalence was low (4.0%, n=1401 cocoons). Mite life-history (parasite or parasitoid) was context dependent, shifting according to the intensity of the attack on a same host. Contrary to the strictly parasitoidic association of M. sellnicki with N. fulva, single mite attacks against E. ruidum did not result in host killing and solitary M. sellnicki (78.6% of the cases) behaved as parasites. However, in 21.4% of the attacks (0.9% of all available host pupae) more than one mite was involved and behaved as parasitoids, draining the host of its internal fuids and killing it. This is the frst association of a macrodinychid mite with a species of the subfamily Ectatomminae, and the frst ant associated mite for which such a context dependent life-style shift is described.


2.
- Artículo con arbitraje
Uncovering species boundaries in the Neotropical ant complex Ectatomma ruidum (Ectatomminae) under the presence of nuclear mitochondrial paralogues
Aguilar Velasco, Reina Gabriela ; Poteaux, Chantal (coaut.) ; Meza Lázaro, Rubí (coaut.) ; Lachaud, Jean Paul (coaut.) ; Dubovikoff, Dmitry A. (coaut.) ; Zaldívar Riverón, Alejandro (coaut.) ;
Contenido en: Zoological Journal of the Linnean Society Vol. 178, no. 2 (October 2016), p. 226–240 ISSN: 1096-3642
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Nuclear mitochondrial (mt) paralogues (numts) are non-functional fragments of mtDNA integrated into the nuclear genome that can overestimate the number of species in analyses based on mtDNA sequences. As numts have relatively slow mutation rates, they can pass undetected by conventional procedures such as inspecting for internal stop codons, indels or apparent polymorphism in chromatograms. Species boundaries based on mtDNA markers therefore require a thorough assessment of numts, especially in insects, where this phenomenon appears to be relatively frequent. Ectatomma ruidum is a widely distributed Neotropical ant species that is distributed from northern Mexico to northern Brazil. Previous behavioural and molecular evidence suggests that this species actually represents a composite taxon. Here we assessed the species boundaries in E. ruidum based on two mt (COI, cyt b) and one nuclear (H3) marker, as well as on external morphology. Ancient and recent mt paralogues were detected in several specimens, although pre-PCR dilution of DNA template helped to recover most of the mt orthologues. Based on the congruence found between our species delineation obtained from the mt genealogies and the discriminated morphospecies, we propose that E. ruidum is actually composed of at least three species. Two of these species have a wide geographical distribution in the Neotropics, whereas the remaining one was restricted to localities situated near the Pacific coast in south-east Mexico. We also found extensive intra- and interspecific variation in the barcoding locus. Moreover, the nuclear evidence suggests the existence of hybrids between two of these species in Oaxaca, south-east Mexico. This study agrees with previous studies of other closely related animal taxa, which have revealed a complex evolutionary history and overlooked species diversity in the latter region.


3.
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Biogeography, cryptic diversity, and queen dimorphism evolution of the Neotropical ant genus Ectatomma Smith, 1958 (Formicidae, Ectatomminae)
Nettel Hernanz, Alejandro ; Lachaud, Jean Paul (coaut.) ; Fresneau, Dominique (coaut.) ; López Muñoz, Román A. (coaut.) ; Poteaux, Chantal (coaut.) ;
Contenido en: Organisms Diversity & Evolution Vol. 15, no. 3 (September 2015), p. 543-553 ISSN: 1439-6092
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Resumen en: Inglés |
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Due to its high biodiversity and its complex climatic and geological history, the Neotropical region has caught the attention of evolutionary and conservation biologists. The Neotropics have an understudied and probably extensive cryptic diversity, stemming from old lineages that have persisted through time with highly similar morphology or from new morphologically undifferentiated sibling species. The wide-ranging Neotropical ant genus Ectatomma currently has only 15 described species, some of which present limited distribution. These ants provide an excellent system for the study of diversification and cryptic diversity in the Neotropics. Ectatomma also displays queen-size dimorphism in some northern populations of its two most common species: a case of true microgyny and a recently described parasitic species. We performed a phylogenetic and biogeographic analysis of Ectatomma species using two mitochondrial genes and one nuclear gene. We also explored the relationship between the history of the genus and the appearance of miniaturized queens. Our analysis recovered a monophyletic Ectatomma that originated in the Parana region of South America. We recorded three likely events of colonization of the Caribbean–Mesoamerican region. We also detected ample evidence of cryptic divergence that deserves a full taxonomic revision of the genus. Miniature queens—microgynes and parasites—represent two independent evolutionary events that appeared in the recent history of the genus.