WorldCat Identities

Calcagno, Vincent

Overview
Works: 6 works in 6 publications in 2 languages and 8 library holdings
Roles: Author, Other, Thesis advisor, Opponent
Publication Timeline
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Most widely held works by Vincent Calcagno
How optimal foragers should respond to habitat changes: a reanalysis of the Marginal Value Theorem by Vincent Calcagno( )

1 edition published in 2013 in English and held by 2 WorldCat member libraries worldwide

How optimal foragers should respond to habitat changes: on the consequences of habitat conversion by Vincent Calcagno( )

1 edition published in 2019 in English and held by 2 WorldCat member libraries worldwide

A guide and method for the drumset teacher by Vincent Calcagno( )

1 edition published in 1984 in English and held by 1 WorldCat member library worldwide

Étude des stratégies de mouvement chez les parasitoïdes du genre Trichogramma : apports des techniques d'analyse d'images automatiques by Victor Burte( )

1 edition published in 2018 in French and held by 1 WorldCat member library worldwide

Parasitoids of the genus Trichogramma are oophagous micro-hymenoptera widely used as biological control agents. My PhD is about the phenotypic characterization of this auxiliary's movement strategies, specifically the movements involved in the exploration of space and the search for host eggs. These phenotypes have great importance in the life cycle of trichogramma, and also of characters of interest to evaluate their effectiveness in biological control program. Trichogramma being very small organisms (less than 0.5 mm), difficult to observe, the study of their movement can take advantage of technological advances in the acquisition and automatic analysis of images. This is the strategy I followed by combining a methodological development component and an experimental component. In a first methodological part, I present three main types of image analysis methods that I used and helped to develop during my thesis. In a second time, I present three applications of these methods to the study of the movement of Trichogramma. First, we characterized in the laboratory the orientation preferences (phototaxis, geotaxis and their interaction) during egg laying in 22 trichogram strains belonging to 6 species. This type of study requires the counting of a large number of eggs (healthy and parasitized), it was developed a new dedicated tool in the form of an ImageJ / FIJI plugin made available to the community. This flexible plugin automates and makes more productive the tasks of counting and evaluation of parasitism rate, making possible screenings of greater magnitude. A great variability could be highlighted within the genus, including between strains of the same species. This suggests that depending on the plant layer to be protected (grass, shrub, tree), it would be possible to select trichogramma's strains to optimize their exploitation of the targeted area. In a second time, we characterized the exploration strategies (velocities, trajectories, ...) of a set of 22 strains from 7 trichogramma species to look for traits specific to each strain or species. I implemented a method for tracking a trichogramma group on video recorded on short time scales using the Ctrax software and R scripts. The aim was to develop a protocol for high-throughput characterization of trichogramma strains movement and to study the variability of these traits within the genus. Finally, we conducted a study of the propagation dynamics in trichogramma group from the species T. cacoeciae, by developing an innovative experimental device to cover scales of time and space greater than those usually imposed by laboratory constraints. Through the use of pictures taken at very high resolution / low frequency and a dedicated analysis pipeline, the diffusion of individuals can be followed in a tunnel longer than 6 meters during a whole day. In particular, I was able to identify the effect of the population density as well as the distribution of resources on the propagation dynamics (diffusion coefficient) and the parasitism efficiency of the tested strain
Modélisation des interactions plant-puceron, en considérant explicitement le rôle des pratiques agricoles : Pêche (Prunus persica) - puceron vert (Myzus persicae) comme cas d'étude by Marta Zaffaroni( )

1 edition published in 2020 in English and held by 1 WorldCat member library worldwide

Les pucerons modifient le développement des plantes et peuvent transmettre des virus, représentant ainsi une menace majeure pour les cultures. Il est possible de réduire la pression exercée par les pucerons sur les plantes et d'améliorer la production agricole en facilitant certains processus écologiques en plus ou en remplacement de l'utilisation de pesticides. Les modèles mathématiques peuvent aider à prédire la direction et la force de ces processus écologiques et ils peuvent révéler l'impact des modes alternatifs de gestion des cultures. La thèse proposée vise à développer des modèles mathématiques basés sur les processus, couplant la physiologie des plantes et la démographie des pucerons, afin de favoriser l'intensification écologique et de réduire l'utilisation des pesticides. Les modèles tiennent compte i) des interactions entre la plante et le puceron, alors que la plupart des modèles de culture ne prennent en compte que l'effet du ravageur sur la plante et non l'inverse, ce qui nuit à la compréhension de la lutte antiparasitaire via les pratiques culturales;et ii) de l'effet des pratiques culturales et du résultat en termes de récolte,questions qui sont généralement absentes dans les modèles écologiques. Je couple tout d'abord un modèle mécaniste de croissance des plantes avec un modèle de population des pucerons, je le calibre pour un système pêche-puceron vert et je l'utilise pour obtenir des informations sur les mécanismes qui sous-tendent la réponse des pucerons à la fertilisation et à l'irrigation. En outre, je développe un modèle épidémiologique qui tient compte explicitement de l'interférence entre deux pucerons vecteurs. J'applique ce modèle pour étudier l'effet de l'interférence inter-spécifique des pucerons dans la propagation des virus des plantes, en tenant compte de l'effet des pratiques agricoles
 
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