Denis Poinsot

Denis Poinsot
Université de Rennes 1 | UR1 · UMR INRA 1349 - Institut de génétique, environnement et protection des plantes (IGEPP)

About

70
Publications
7,371
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1,613
Citations
Citations since 2016
31 Research Items
683 Citations
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2016201720182019202020212022020406080100120
2016201720182019202020212022020406080100120
2016201720182019202020212022020406080100120

Publications

Publications (70)
Article
Full-text available
Facultative intracellular symbionts like the α-proteobacteria Wolbachia influence their insect host phenotype but little is known about how much they affect their host microbiota. Here, we quantified the impact of Wolbachia infection on the bacterial community of the cabbage root fly Delia radicum by comparing the microbiota of Wolbachia-free and i...
Article
Full-text available
Insect symbionts benefit their host and their study requires large spectrum antibiotic use like tetracycline to weaken or suppress symbiotic communities. While antibiotics have a negative impact on insect fitness, little is known about antibiotic effects on insect microbial communities and how long they last. We characterized the bacterial communit...
Article
Full-text available
The development of integrated pest management strategies becomes more and more pressing in view of potential harmful effects of synthetic pesticides on the environment and human health. A promising alternative strategy against Delia radicum is the use of trap crops. Chinese cabbage (Brassica rapa subsp. pekinensis and subsp. chinensis) is a highly...
Article
Wolbachia bacteria inhabit the cells of about half of all arthropod species, an unparalleled success stemming in large part from selfish invasive strategies. Cytoplasmic incompatibility (CI), whereby the symbiont makes itself essential to embryo viability, is the most common of these and constitutes a promising weapon against vector-borne diseases....
Presentation
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Talk during Session 1 (Exploring Interactions within Phytobiomes) at the International Phytobiomes Conference 2018 (4-6 December) in Montpellier, France.
Presentation
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During the International Conference on Ecological Sciences - Sfecologie 2018 that took place in Rennes (France) during October 22-25, I presented one of my studies in the "holobiont and extended phenotype" session: Lachaise, Ourry et al., Insect Science (2017)
Article
Full-text available
The “push-pull” strategy aims at manipulating insect pest behavior using a combination of attractive and repulsive stimuli using either plants derived volatile organic compounds or insect host plant preferences. In a field experiment using broccoli as a crop, we combined in a “push-pull” context the oviposition deterrent effect of dimethyl disulfid...
Article
Wolbachia is an endocellular bacteria infecting arthropods and nematodes and is only transmitted vertically by females via the cytoplasm of the egg. It is often a manipulator of host reproduction, causing cytoplasmic incompatibility, thelytokous parthenogenesis, feminization or male killing, which all increase the proportion of infected females in...
Presentation
Full-text available
During the 21st Crucifer Genetics Conference - Brassica 2018 that took place in Saint Malo (France) during the July 1-4 2018, I presented the one of my studies in the "Pathogen and insect resistance, biocontrol, crop protection" session: Ourry et al., Frontiers in Ecology and Evolution (2018).
Article
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Recent studies are unraveling the impact of microorganisms from the roots and rhizosphere on interactions between plants and herbivorous insects and are gradually changing our perception of the microorganisms' capacity to affect plant defenses, but the reverse effect has seldom been investigated. Our study aimed at determining how plant herbivory i...
Article
Interactions between plants and phytophagous insects play an important part in shaping the biochemical composition of plants. Reciprocally plant metabolites can influence major life history traits in these insects and largely contribute to their fitness. Plant rhizospheric microorganisms are an important biotic factor modulating plant metabolites a...
Article
Full-text available
The use of volatile organic compounds (VOCs) derived from plants to manipulate insect pest behavior can be applied in an integrated pest management strategy (IPM) using a combination of attractive and repulsive stimuli. The “push–pull” strategy was developed on this idea in order to disturb and modify the distribution and abundance of pests to prot...
Article
The use of volatile organic compounds (VOCs) derived from plants to manipulate insect pest behavior can be applied in an integrated pest management strategy (IPM) using a combination of attractive and repulsive stimuli. The "push-pull" strategy was developed on this idea in order to disturb and modify the distribution and abundance of pests to prot...
Article
Full-text available
When specialists and generalists compete for a limited resource, specialists are more constrained because they are less likely to find an alternative resource. In parasitoids with overlapping host ranges, asymmetric competition should therefore exist where specialists are more likely to win the host in a contest. Competition between parasitoids has...
Article
Full-text available
All animals are infected by microbial partners that can be passengers or residents and influence many biological traits of their hosts. Even if important factors that structure the composition and abundance of microbial communities within and among host individuals have been recently described, such as diet, developmental stage or phylogeny, few st...
Data
Rarefaction curves showing the number of detected MOTUs as a function of the number of high quality reads in Delia radicum (A), Trybliographa rapae (B), Aleochara bilineata (C) and Aleochara bipustulata (D). Coding of populations sampled and homology thresholds (95%, 97% and 99%): see legend included in the figure. (TIF)
Data
Reference sequences of 16S rDNA genes of Wolbachia, Spiroplasma, Rickettsia, Ehrlichia and Mycoplasma. (DOCX)
Article
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Agriculture intensification has deeply modified agroecosystems from field to landscape scales. To achieve successful pest control using natural enemies, understanding species interactions over all scales remains a challenge. Using the cabbage root fly as a model, we studied whether field and landscape characteristics influenced colonization and inf...
Article
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This article documents the addition of 234 microsatellite marker loci to the Molecular Ecology Resources Database. Loci were developed for the following species: Acipenser sinensis, Aleochara bilineata, Aleochara bipustulata, Barbus meridionalis, Colossoma macropomum, Delia radicum, Drosophila nigrosparsa, Fontainea picrosperma, Helianthemum cinere...
Article
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Parasitoids of phytophagous insects face a detect-ability–reliability dilemma when foraging for hosts. Plant-related cues are easily detectable, but do not guarantee the presence of the host. Host-related cues are very reliable, but much harder to detect from a distance. Little is known in particular about the way coleopteran parasitoid females use...
Article
Induced responses to insect herbivory are a common phenomenon in the plant kingdom. So far, induced responses have mostly investigated in aerial plant parts. Recently it was found that root herbivore may also elicit both local and systemic responses affecting aboveground herbivores and their natural enemies. Using broccoli (Brassica oleracea subsp....
Article
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Kin recognition is a complex cognitive process, where an individual should detect a phenotypic cue and compare it to an internal template, which might be genetically determined (i.e., innate or acquired). Kin recognition mechanisms will depend on whether previous encounters with kin are possible or not to form the individual internal template. When...
Article
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The production of cues that indicate the identity of the sender represents an important aspect of recognition because it may mediate kin recognition and altruism. Although kin recognition cues have often been studied in social insects, only a few studies have reported kin recognition in solitary insects. Furthermore, contrary to cues used for paren...
Article
By contrast to females that can maximize reproductive success with only one or a few copulations, males generally increase their fitness with frequency of mating. Sperm storage and allocation is therefore crucial for both male and female fitness. Sperm storage in Aleochara bilineata (Coleoptera; Staphylinidae) is investigated by measuring the numbe...
Article
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Most terrestrial prey species are assumed to assess predation risk by detecting predators directly rather than using cues of previous attacks on conspecifics. However, such cues might represent valuable information, and prey can be expected to respond to the presence of congeners killed by enemies. Such cues are available in aphid colonies attacked...
Article
Wolbachia are endosymbiotic alpha-proteobacteria harboured by terrestrial arthropods and filarial nematodes, where they are maternally transmitted through egg cytoplasm. According to the host group, Wolbachia have developed two contrasting symbiotic strategies. In arthropods, symbiosis is secondary (i.e. facultative), and Wolbachia insure their tra...
Article
Full-text available
Dimethyl disulfide (DMDS) was identified as a major volatile constituent of Brassica napus roots heavily infested by Delia radicum, the cabbage root fly. Attractiveness of this widespread compound was tested in the field in a naturally complex odorous environment. By using an original setup especially designed for ground dwelling beetles, different...
Article
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Genomic imprinting corresponds to the differential expression of a gene according to its paternal or maternal origin. The kinship theory of genomic imprinting proposes that maternally or paternally inherited genes may be in conflict over their effects on kin differently related along the paternal or maternal line. Most examples supporting the kinsh...
Article
Intraspecific competition for resources is common in animals and may lead to physical contests. Contest outcomes and aggressiveness can be influenced by the resource holding potential of contestants but also by their perception of the resource value (RV). Competitors may assess resource quality directly (real RV) but may also estimate it according...
Article
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Kin selection theory predicts altruism between related individuals, which requires the ability to recognize kin from non-kin. In insects, kin discrimination associated with altruistic behaviour is well-known in clonal and social species but in very few solitary insects. Here, we report that the solitary larvae of a non-social insect Aleochara bilin...
Article
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The optimal residence time of a forager exploiting a resource patch in the absence of competitors has been much studied since the development of the marginal value theorem. However, several foragers are frequently observed exploiting the same patch simultaneously, and patch residence time has been surprisingly little studied in such competitive sit...
Article
Cytoplasmic incompatibility (CI) is induced in arthropods by the maternally inherited bacterium Wolbachia. When infected males mate with uninfected females or with females bearing a different Wolbachia variant, paternal chromosomes behave abnormally and embryos die. This pattern can be interpreted as resulting from two bacterial effects: One (usual...
Article
Abstract . -Cytoplasmic incompatibility (CI) is induced in arthropods by the maternally inherited bacterium Wolbachia. When infected males mate with uninfected females or with females bearing a different Wolbachia variant, paternal chromosomes behave abnormally and embryos die. This pattern can be interpreted as resulting from two bacterial effects...
Article
Full-text available
In this paper, we compare the host selection behaviours of two parasitoids, Aphidius rhopalosiphi and Aphidius picipes, in order to analyse whether behavioural adaptations to the defensive behaviour of their host (the grain aphid Sitobion avenae) could, in part, be responsible for the simultaneous presence of both species in cereal fields. The ovip...
Article
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In solitary parasitoid species, superparasitism incurs a high cost because only one individual can emerge per host. While avoiding already-parasitized hosts seems advantageous, it requires an ability to discriminate between parasitized and unparasitized hosts. The ability to discriminate can be based on physical or chemical cues or signal associate...
Article
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Host rejection, superparasitism, and ovicide are three possible host selection strategies that parasitoid females can adopt when they encounter parasitized hosts. These differ in costs (in terms of time and energy required) and benefits (in terms of number and quality of offspring produced). Their relative payoff should vary with patch quality, (i....
Article
Optimal Foraging Theory predicts that parasitoid females should optimize their host selection to maximize their lifetime fitness gain and parasitize the most profitable hosts. In particular, in solitary parasitoids, females should avoid superparasitism, at least when sufficient unparasitized hosts are available. However, when unparasitized hosts ar...
Article
Full-text available
In solitary parasitoids, only one individual can emerge per host. Therefore, females should reject already parasitized hosts. However, when unparasitized hosts are scarce, superparasitism becomes advantageous and females should choose hosts that offer the best survival chances to their progeny, which depend on the developmental stage of the first p...
Article
The endocellular bacterium Wolbachia manipulates the reproduction of its arthropod hosts for its own benefit by various means, the most widespread being cytoplasmic incompatibility (CI). To date, the molecular mechanism involved in CI has not been elucidated. We examine here three different CI models described in previous literature, namely, the "l...
Article
Although hyperparasitism frequently occur in parasitic insects, many aspects of this strategy remain unknown. We investigated possible fitness costs of hyperparasitism as influenced by host size. Our study was conducted with the facultative hyperparasitoid Pachycrepoideus dubius Ashmead (Hymenoptera: Pteromalidae), which parasitizes host species di...
Article
Summary 1. Female parasitoids that lay their eggs away from potential host insects are supposed to have only a minor influence on the fitness of their own progeny, as they do not select and evaluate directly the quality of hosts for their offspring. Aleochara bilineata Gyll. (Coleoptera: Staphylinidae) females oviposit near to cabbage plants infest...
Article
Full-text available
Wolbachia pipientis (Hertig) (Rickettsiaceae) is an endocellular bacterium infecting numerous species of arthropods. The bacterium is harboured by males and females but is only transmitted maternally because spermatocytes shed their Wolbachia during maturation. The presence of this endosymbiont can lead to feminisation of the host, parthenogenesis,...
Article
Wolbachia are maternally transmitted endocellular bacteria infecting several arthropod species. In order to study Wolbachia segregation rate, Drosophila simulans females from an Indo-Pacific population (Seychelles) bi-infected by the two Wolbachia variants wHa and wNo were backcrossed to uninfected males in two conditions. In the first case, Seyche...
Article
Full-text available
Wolbachia are maternally transmitted endocellular bacteria causing a reproductive incompatibility called cytoplasmic incompatibility (CI) in several arthropod species, including Drosophila. CI results in embryonic mortality in incompatible crosses. The only bacterial strain known to infect Drosophila melanogaster (wDm) was transferred from a D. mel...
Article
The endocytoplasmic bacterium Wolbachia causes the death of arthropod embryos, when present in reproductive organs, by cytoplasmic incompatibility. Wolbachia is harboured in both sexes but transmission is maternal only. Cytoplasmic incompatibility occurs when infected males inseminate uninfected females or females bearing a different variant of Wol...
Article
Wolbachia are maternally-transmitted endocellular bacteria infecting several arthropod species. In order to study the possibility of Wolbachia segregation in a naturally bi-infected host, isofemale lines from a bi-infected Drosophila simulans (Sturtevant) strain from Nouma (New Caledonia) were backcrossed using uninfected males carrying the same nu...
Article
Fitness traits of three Drosophila simulans strains infected by endocellular bacteria belonging to the genus Wolbachia have been compared with those of replicate stocks previously cured from the infection by an antibiotic treatment. The traits measured were development time, egg-to-adult viability, egg hatch, productivity, fecundity, and the number...