Search results for "PVS"

Mating Status of an Herbivorous Stink Bug Female Affects the Emission of Oviposition-Induced Plant Volatiles Exploited by an Egg Parasitoid

2019

Insect parasitoids are under selection pressure to optimize their host location strategy in order to maximize fitness. In parasitoid species that develop on host eggs, one of these strategies consists in the exploitation of oviposition-induced plant volatiles (OIPVs), specific blends of volatile organic compounds released by plants in response to egg deposition by herbivorous insects. Plants can recognize insect oviposition via elicitors that trigger OIPVs, but very few elicitors have been characterized so far. In particular, the source and the nature of the elicitor responsible of egg parasitoid recruitment in the case of plants induced with oviposition by stink bugs are still unknown. In …

Discrimination des expressions faciales et environnement olfactif – Corrélats cérébraux en électroencéphalographie (EEG) chez l’adulte et le très jeu…

2019

This thesis examines the mechanisms subtending the perception of emotional facial expressions and their early development using a Fast Periodic Visual Presentation (FPVS) approach coupled with electroencephalography (EEG). More specifically, we tried to characterize brain responses reflecting facial expression discrimination and to determine whether hedonic odor contexts influence these responses in adults (studies 1 and 2), and in infants at different developmental stages (studies 3 and 4).We showed specific responses to the discrimination of every facial expression in the adult brain, indicating rapid and automatic categorization of basic facial expressions (study 1). In addition, we reve…

Finding an egg in a haystack: variation in chemical cue use by egg parasitoids of herbivorous insects

2023

Egg parasitoids of herbivorous insects use an interplay of short- and long-range chemical cues emitted by hosts and host plants to find eggs to parasitize. Volatile compounds that attract egg parasitoids can be identified via behavioral assays and used to manipulate parasitoid behavior in the field for biological control of herbivorous pests. However, how and when a particular cue will be used varies over the life of an individual, as well as at and below species level. Future research should expand taxonomic coverage to explore variation in chemical cue use in more natural, dynamic settings. More nuanced understanding of the variability of egg parasitoid host-finding strategies will aid in…

Attraction of egg-killing parasitoids toward induced plant volatiles in a multi-herbivore context

2015

In response to insect herbivory, plants emit volatile organic compounds which may act as indirect plant defenses by attracting natural enemies of the attacking herbivore. In nature, plants are often attacked by multiple herbivores, but the majority of studies which have investigated indirect plant defenses to date have focused on the recruitment of different parasitoid species in a single-herbivore context. Here, we report our investigation on the attraction of egg parasitoids of lepidopteran hosts (Trichogramma brassicae and T. evanescens) toward plant volatiles induced by different insect herbivores in olfactometer bioassays. We used a system consisting of a native crucifer, Brassica nigr…

Block-Based Models and Theorem Proving in Model-Based Development

2021

This paper presents a methodology to integrate computer-assisted theorem proving into a standard workflow for model-based development that uses a block-based language as a modeling and simulation tool. The theorem prover provides confidence in the results of the analysis as it guides the developers towards a correct formalization of the system under development.

Effect of dual biotic stress on plant volatile synomones used by an egg parasitoid

Plants respond to arthropod herbivory with the induction of volatiles called herbivore-induced plant volatiles (HIPVs). These volatiles appear to be important sources of information that attract parasitoids. Parasitic wasps foraging decisions are often affected by community characteristics such as community diversity and complexity. As part of a complex habitat, the presence of unsuitable hosts (non-host) may affect foraging behavior of parasitoids. In this chapter, we outline the importance of the presence of unsuitable herbivores on the behavioral responses of parasitoids. First we review the foraging behavior of parasitoid in tritrophic interaction. Then we focus on foraging behavior by …

Cryopreservation of white mulberry (Morus alba L.) by encapsulation-dehydration and vitrification

2011

Shoot apices of in vitro-grown plantlets of white mulberry, Morus alba L. cv Florio, were cryopreserved using either encapsulation-dehydration or vitrification. For encapsulation-dehydration, alginate beads containing apices were dehydrated for 1, 3, 5 or 7 days in a liquid medium containing various sucrose concentrations (0.5, 0.75, 1.0 or 1.25 M). Bead desiccation was performed using silica gel for either 0, 4, 6, 8, 9 or 14 h. For vitrification, apices were directly immersed for either 5, 15, 30 or 60 min in a vitrification solution (PVS2). Following encapsulation-dehydration, treatment of alginate beads with 0.75 M sucrose was more effective in promoting re-growth of explants after imme…

Discrimination des expressions faciales et environnement olfactif - Corrélats cérébraux en électroencéphalographie (EEG) chez l'adulte et le très jeu…

2019

This thesis examines the mechanisms subtending the perception of emotional facial expressions and their early development using a Fast Periodic Visual Presentation (FPVS) approach coupled with electroencephalography (EEG). More specifically, we tried to characterize brain responses reflecting facial expression discrimination and to determine whether hedonic odor contexts influence these responses in adults (studies 1 and 2), and in infants at different developmental stages (studies 3 and 4). We showed specific responses to the discrimination of every facial expression in the adult brain, indicating rapid and automatic categorization of basic facial expressions (study 1). In addition, we rev…

Maternal odor selectively enhances the categorization of face(like) stimuli in the 4 month-old infant brain

2020

Présentation Poster; International audience; In the 4-month-old infant brain, the visual categorization of natural face images is enhanced by concomitant maternal odor (Leleu et al., 2019), providing support for the early perception of congruent associations between co-occurring inputs from multiple senses. Here, we further explore whether this maternal odor effect is selective to faces or if it can be explained by a more general influence of salient odor cues on the perception of any visual object category. In Experiment 1, scalp electroencephalogram was recorded during a fast periodic visual stimulation (FPVS-EEG) while 4-month-old infants were exposed to the maternal vs. a control odor. …

When your nose knows what you see : multisensory development of visual categorization : evidence from odor-driven face categorization in the human br…

2020

This thesis examines whether and how odors contribute to the development of visual categorization in the human brain using fast periodic visual stimulation coupled with scalp electroencephalography (FPVS-EEG). Specifically, we sought to characterize if a neural visual response selective to the face category is modulated by the presence of a body odor in both infants (Study 1, 2, 3) and adults (Study 4).In infants, the selectivity of the odor effect on visual categorization was addressed by testing separately three categories in three groups of 4-month-old infants presented with a control odor or their mother’s odor. We observed that a face-selective response is largely enhanced by maternal …