Xavier Fauvergue

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The patch exploitation strategy of females of the insect parasitoid Trichogramma brassicae was studied on patches containing different proportions of hosts that were previously attacked by conspecific females. On average, T. brassicae females spent more time on patches of higher quality, and all patches were reduced to the same level of profitability before(More)
Populations are introduced into novel environments in different contexts, one being the biological control of pests. Despite intense efforts, less than half introduced biological control agents establish. Among the possible approaches to improve biological control, one is to better understand the processes that underpin introductions and contribute to(More)
In field observations and laboratory experiments, we found that virgin females of the solitary parasitoid Aphelinus asychis did not emit a volatile sex pheromone to attract males, contrary to what has been reported in many other parasitoid species. Instead, we found that virgin females deposited a sex pheromone on the substrate to which males responded by(More)
Charnov’s marginal value theorem predicts that female parasitoids should exploit patches of their hosts until their instantaneous rate of fitness gain reaches a marginal value. The consequences of this are that: (1) better patches should be exploited for a longer time; (2) as travel time between patches increases, so does the patch residence time; and (3)(More)
Populations spatially structured at the time of mating may experience local mate competition (LMC) and inbreeding, two factors known to select, in haplodiploid organisms. for a female biased sex ratio. Populations of the two Drosophila parasitoids Leptopilina boulardi and L. heleroloma could have such a structure because although males and females develop(More)
INRA, UMR 1355 Institut Sophia Agrobiotech, Equipe ‘Biologie des Populations Introduites’, 06903 Sophia Antipolis, France Université de Nice Sophia Antipolis, UMR Institut Sophia Agrobiotech, Equipe ‘Biologie des Populations Introduites’, 06903 Sophia Antipolis, France CNRS, UMR 7254 Institut Sophia Agrobiotech, Equipe ‘Biologie des Populations(More)
Cédric Tentelier, Emmanuel Desouhant, and Xavier Fauvergue Unité Mixte de Recherche 1112, Réponse des Organismes aux Stress Environmentaux, Institut National de la Recherche Agronomique, 400 route des Chappes BP 167, 06903 Sophia Antipolis Cedex, France and Unité Mixte de Recherche 5558 ‘‘Biométrie et Biologie Evolutive,’’ Université Claude Bernard Lyon 1,(More)
In fall, Myzus persicae (Sulzer) (Homoptera: Aphididae) may exhibit population resurgence in winter oilseed rape in France. This resurgence may arise from pyrethroid treatments against Coleoptera (Psylliodes chrysocephala L.) that either kill parasitoids present during treatment or prevent recolonization by off-crop parasitoids. We studied the impact of(More)
In haplodiploid organisms, virgin females can produce offspring, albeit only sons. They may therefore face a trade-off between either: (1) searching for hosts and producing sons immediately; or (2) searching for mates and perhaps producing both sons and daughters later in life. Although this trade-off raises a theoretical interest, it has not been(More)
Microsatellite loci were isolated from the aphid parasitoid Lysiphlebus testaceipes (Hymenoptera: Braconidae). Ten loci were obtained from an enriched partial genomic library. Genetic diversity was analysed at seven of these loci and two natural populations, one on oleander and one on citrus. The observed number of alleles ranged from one to 17, and the(More)