Université de Neuchâtel

Anthropogenic effects on population genetics of phytophagous insects associated with domesticated plants

Alvarez, Nadir ; Hossaert-McKey, Martine ; Restoux, Gwendal ; Delgado-Salinas, Alfonso ; Benrey, Betty

In: Evolution, 2007, vol. 61, no. 12, p. 2986-2996

The hypothesis of isolation by distance (IBD) predicts that genetic differentiation between populations increases with geographic distance. However, gene flow is governed by numerous factors and the correlation between genetic differentiation and geographic distance is never simply linear. In this study, we analyze the interaction between the effects of geographic distance and of wild or...

Université de Neuchâtel

Parallels in the evolution of the two largest New and Old World seed-beetle genera (Coleoptera, Bruchidae)

Kergoat, G. J. ; Alvarez, Nadir ; Hossaert-McKey, Martine ; Faure, N. ; Silvain, J.-F.

In: Molecular Ecology, 2005, vol. 14, no. 13, p. 4003-4021

This study provides the first phylogenetic analysis of a large sample of the two largest genera of seed-beetles, Acanthoscelides Schilsky and Bruchidius Schilsky, which mostly feed on legumes (Fabaceae). The goal of this study was to investigate evolutionary patterns in relation to biogeography and host-plant associations. We used three mitochondrial molecular markers and parsimony...

Université de Neuchâtel

Farmers' practices, metapopulation dynamics, and conservation of agricultural biodiversity on-farm: a case study of sorghum among the Duupa in sub-sahelian Cameroon

Alvarez, Nadir ; Garine, Eric ; Khasah, Celestin ; Dounias, Edmond ; Hossaert-McKey, Martine ; McKey, Doyle

In: Biological Conservation, 2005, vol. 121, no. 4, p. 533-543

In many traditionally managed agroecosystems, populations of domesticated plants maintain high levels of genetic diversity. The threat of erosion of this diversity is a current conservation concern, motivating studies of how diversity can be maintained by in situ conservation measures. Precisely how the biological traits of plants and the cultural practices of farmers act on fundamental...

Université de Neuchâtel

Isolation and characterization of polymorphic microsatellite loci in Acanthoscelides obvelatus Say (Coleoptera: Bruchidae)

Alvarez, Nadir ; Born, Céline ; Risterucci, A.-M. ; Sourrouille, P. ; Benrey, Betty ; Hossaert-McKey, Martine

In: Molecular Ecology Notes, 2004, vol. 4, no. 4, p. 683

Six microsatellite loci were isolated from the bruchid Acanthoscelides obtectus Say (Coleoptera: Bruchidae). Each locus was polymorphic, with the number of alleles ranging from 3 to 18. We found high levels of within-population variation at most loci, with heterozygosities ranging from 0 to 0.75. Cross-species amplification of these loci was tested in two other species of the genus...

Université de Neuchâtel

Isolation and characterization of polymorphic microsatellite loci in Acanthoscelides obvelatus Bridwell (Coleoptera: Bruchidae)

Alvarez, Nadir ; Aebi, Alexandre ; Risterucci, A.-M. ; Hossaert-McKey, Martine ; Benrey, Betty

In: Molecular Ecology Notes, 2003, vol. 3, no. 1, p. 12-14

Five microsatellite loci were isolated from the bruchid Acanthoscelides obvelatus Bridwell (Coleoptera: Bruchidae). Each locus was polymorphic, with the number of alleles ranging from two to 15. We found high levels of within-population variation at most loci, with heterozygosity ranging from 0.182 to 0.900. Cross-species amplification of these loci was tested in two other species of the...

Université de Neuchâtel

Ancient and recent evolutionary history of the bruchid beetle, Acanthoscelides obtectus Say, a cosmopolitan pest of beans

Alvarez, Nadir ; McKey, Doyle ; Hossaert-McKey, Martine ; Born, Céline ; Mercier, Lény ; Benrey, Betty

In: Molecular Ecology, 2005, vol. 14, no. 4, p. 1015–1024

Acanthoscelides obtectus Say is a bruchid species of Neotropical origin, and is specialized on beans of the Phaseolus vulgaris L. group. Since the domestication and diffusion of beans, A. obtectus has become cosmopolitan through human-mediated migrations and is now a major pest in bean granaries. Using phylogeographic methods applied to mitochondrial DNA (mtDNA) and nuclear...

Université de Neuchâtel

Phylogenetic relationships in the Neotropical bruchid genus Acanthoscelides (Bruchinae, Bruchidae, Coleoptera)

Alvarez, Nadir ; Romero Napoles, J. ; Anton, K.-W. ; Benrey, Betty ; Hossaert-McKey, Martine

In: Journal of Zoological Systematics and Evolutionary Research, 2006, vol. 44, no. 1, p. 63-74

Adaptation to host-plant defences through key innovations is a driving force of evolution in phytophagous insects. Species of the neotropical bruchid genus Acanthoscelides Schilsky are known to be associated with specific host plants. The speciation processes involved in such specialization pattern that have produced these specific associations may reflect radiations linked to particular...

Université de Neuchâtel

Sibling species of bean bruchids: a morphological and phylogenetic study of Acanthoscelides obtectus Say and Acanthoscelides obvelatus Bridwell

Alvarez, Nadir ; Hossaert-McKey, Martine ; Rasplus, J.-Y. ; McKey, Doyle ; Mercier, Lény ; Soldati, L. ; Aebi, Alexandre ; Shani, T. ; Benrey, Betty

In: Journal of Zoological Systematics and Evolutionary Research, 2005, vol. 43, no. 1, p. 29-37

Acanthoscelides Schilsky is a large genus of neotropical bruchid beetles, in which most species show host plant specialization. Acanthoscelides obtectus and Acanthoscelides obvelatus are two sibling species specialized on Phaseolus beans, and are therefore considered pests. Up to now, the status of these two taxa has remained unclear, the few studies conducted having failed...

Université de Neuchâtel

Ecological distribution and niche segregation of sibling species: the case of bean beetles, Acanthoscelides obtectus Say and A. obvelatus Bridwell

Alvarez, Nadir ; Mercier, Lény ; Hossaert-McKey, Martine ; Contreras-Garduño, Jorge ; Kunstler Georges ; Aebi, Alexandre ; Benrey, Betty

In: Ecological Entomology, 2006, vol. 31, no. 6, p. 582–590

1. Molecular techniques have greatly added to the number of known sympatric cryptic species in insects. Ecological differences between these newly distinguished species are little explored, but niches often appear to overlap strongly. These cases are good models for exploring new ideas about species coexistence and community structure. 2. Acanthoscelides obtectus and A....

Université de Neuchâtel

Phylogeographic support for horizontal gene transfer involving sympatric bruchid species

Alvarez, Nadir ; Benrey, Betty ; Hossaert-McKey, Martine ; Grill, Andrea ; McKey, Doyle ; Galtier, Nicolas

In: Biology Direct, 2006, vol. 1, no. 21, p. 1-11

Background We report on the probable horizontal transfer of a mitochondrial gene, cytb, between species of Neotropical bruchid beetles, in a zone where these species are sympatric. The bruchid beetles Acanthoscelides obtectus, A. obvelatus, A. argillaceus and Zabrotes subfasciatus develop on various bean species in Mexico. Whereas A....