Search results for "parasitoïde"
showing 5 items of 5 documents
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 …
Lobesia botrana larvae develop faster in the presence of parasitoids.
2013
3 pages; International audience; To combat parasitism hosts often rely on their immune system, which is the last line of defense. However, the immune system may not always be effective, and other non-immunological defenses might be favored to reduce the cost of parasite infection. Here we report that larvae of the moth Lobesia botrana can rapidly accelerate their development and reach maturity earlier in response to cues perceived at a distance from parasitoids. Such a phenotypically plastic life history shift, induced by the perception of deadly enemies in the environment, is likely to be an adaptive defensive strategy to prevent parasitoid attack, and has important implications in host-pa…
Contrôle des ravageurs de cultures par les ennemis naturels : la plante hôte facteur régulateur du système immunitaire des chenilles de vers de la gr…
2013
10 pages; National audience; En raison des nombreux dégâts occasionnés par les vers de la grappe dans les vignobles, trouver un moyen de lutte efficace est devenu un réel challenge. A l’heure actuelle, la lutte biologique apparaît comme une alternative possible à la lutte chimique. Cependant, les résultats obtenus suite aux lâchers de parasitoïdes sont extrêmement variables dans leur efficacité. Des études approfondies de la biologie des vers de la grappe et de leurs parasitoïdes sont donc nécessaires afin d’affiner les méthodes de lutte biologique. Le système immunitaire des insectes représente la dernière ligne de défense des phytophages contre les parasitoïdes. Dans cette étude nous mett…
Impacts of climate change on the performance of an insect pest and associated consequences for tritrophic interactions
2019
Global warming poses a major challenge to living organisms, particularly for ectothermic animals like insects, whose physiology and behaviour are closely related with direct thermal surroundings. This thesis aims at experimentally investigating the impacts of climate change on the overall performance of a major grapevine pest, the European grapevine moth (Lobesia botrana), and the associated consequences for interactions involving this phytophagous insect and adjacent trophic levels, more specifically natural enemies (parasitoids). The experiments conducted focus on three facets of climate change: an increase in mean temperature, an alteration of daily thermal range, and the occurrence of h…
Intraguild interactions between two egg parasitoids of a true bug in semi-field and field conditions.
2014
International audience; Research on interspecific competitive interactions among insect parasitoids has often been characterized by laboratory studies in which host insects are exposed to female parasitoids of different species in various sequences and combinations. In the last years, an increasing number of studies have investigated interspecific interactions under field and semi-field conditions although just a few number of works focused on egg parasitoids. In this work, we undertook a two-year study to investigate interspecific interactions between Trissolcus basalis (Wollaston) (Hymenoptera: Platygastridae) and Ooencyrtus telenomicida (Vassiliev) (Hymenoptera: Encyrtidae), two egg para…