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P J Charmillot - One of the best experts on this subject based on the ideXlab platform.
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efficacite larvicide et ovicide sur les vers de la grappe lobesia botrana et eupocelia ambiguella de differents insecticides appliques par trempage des grappes
Revue suisse de viticulture arboriculture et horticulture, 2006Co-Authors: P J CharmillotAbstract:L'activite larvicide et ovicide de quelques insecticides appliques a differentes concentrations par trempage des grappes contre les vers de la grappe eudemis Lobesia botrana et cochylis Eupoecilia ambiguella a ete determinee. La plupart des produits testes ont une efficacite larvicide nettement plus elevee contre eudemis que contre cochylis. En effet, les LC 50 des substances actives emamectine, spinosad, methoxyfenozide et indoxacarbe sont situees entre 0,003 et 0,05 ppm pour eudemis et entre 0,03 et 0,3 ppm pour cochylis. Le fenoxycarbe, typiquement ovicide, et le Lufox, qui combine l'effet ovicide du fenoxycarbe a l'action larvicide du lufenuron, sont tous deux plus efficaces sur cochylis que sur eudemis. Les autres produits testes n'ont pas d'activite ovicide digne d'interet, sauf le methoxyfenozide et le flufenoxuron qui sont relativement efficaces contre eudemis.
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isonet une nouvelle gamme de diffuseurs pour la lutte par confusion contre les vers de la grappe
Revue suisse de viticulture arboriculture et horticulture, 2004Co-Authors: P J CharmillotAbstract:Les diffuseurs Isonet, destines a la lutte par confusion contre les vers de la grappe cochylis Eupoecilia ambiguella et eudemis Lobesia botrana, ont ete testes dans le canton de Vaud de 2001 a 2003, sur une surface totale d'environ 680 ha de vignoble. Les pieges sexuels installes dans les essais n'ont pratiquement rien capture. En premiere generation, les attaques sur grappes ont toujours ete considerablement reduites par rapport aux vignobles de reference de la meme region. En seconde generation, la technique de confusion a ete, dans la majorite des cas, plus efficace que la lutte au moyen d'insecticides classiques. Cependant, un traitement complementaire localise s'est parfois avere necessaire, essentiellement dans des parcelles insuffisamment isolees, dans des bordures de vignoble, en raison d'une application trop tardive des diffuseurs ou d'une pression initiale trop elevee des ravageurs. L'emission des attractifs, estimee par pesee hebdomadaire et par analyse chromatographique en phase gazeuse (GC) de diffuseurs exposes dans les vignes, est tres reguliere durant toute la saison et assure une persistance de l'action au-dela de la periode de vol des deux ravageurs.
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effet du regulateur de croissance d insectes rci tebufenozide sur les œufs les larves et les papillons des vers de la grappe lobesia botrana den schiff et Eupoecilia ambiguella hb
Mitteilungen der Schweizerischen Entomologischen Gesellschaft, 1994Co-Authors: P J Charmillot, R Favre, D Pasquier, M Rhyn, Alessandra ScalcoAbstract:L'effet du tebufenozide, un nouveau regulateur de croissance d'insectes (RCI) agoniste de l'hormone de mue ecdysone, est teste en laboratoire sur les vers de la grappe eudemis L. botrana et cochylis E. ambiguella. Ce produit n'a pas d'activite ovicide, quel que soit l'âge des oeufs traites. En traitement direct sur des larves âgees de 12 jours, la LC 50 se situe a moins de 5 ppm sur L. botrana et a environ 20 a 30 ppm sur E. ambiguella. Le tebufenozide est actif sur tous les stades larvaires mais son efficacite diminue progressivement avec l'augmentation de l'âge des larves, particulierement lorsqu'il est applique a faible concentration sur E. ambiguella
Patrick M Guerin - One of the best experts on this subject based on the ideXlab platform.
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small cages with insect couples provide a simple method for a preliminary assessment of mating disruption
The Scientific World Journal, 2012Co-Authors: Francoise Briand, Patrick M Guerin, Pierrejoseph Charmillot, Patrik KehrliAbstract:Mating disruption by sex pheromones is a sustainable, effective and widely used pest management scheme. A drawback of this technique is its challenging assessment of effectiveness in the field (e.g., spatial scale, pest density). The aim of this work was to facilitate the evaluation of field-deployed pheromone dispensers. We tested the suitability of small insect field cages for a pre-evaluation of the impact of sex pheromones on mating using the grape moths Eupoecilia ambiguella and Lobesia botrana, two major pests in vineyards. Cages consisted of a cubic metal frame of 35 cm sides, which was covered with a mosquito net of 1500 μm mesh size. Cages were installed in the centre of pheromone-treated and untreated vineyards. In several trials, 1 to 20 couples of grape moths per cage were released for one to three nights. The proportion of mated females was between 15 to 70% lower in pheromone-treated compared to untreated vineyards. Overall, the exposure of eight couples for one night was adequate for comparing different control schemes. Small cages may therefore provide a fast and cheap method to compare the effectiveness of pheromone dispensers under standardised semi-field conditions and may help predict the value of setting-up large-scale field trials.
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Host plant volatiles serve to increase the response of male European grape berry moths, Eupoecilia ambiguella, to their sex pheromone
Journal of Comparative Physiology A, 2009Co-Authors: Daniela Schmidt-büsser, Martin Arx, Patrick M GuerinAbstract:The European grape berry moth is an important pest in vineyards. Males respond to the female-produced sex pheromone released from a piezo nebulizer in a dose-dependent manner in a wind tunnel:
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host plant volatiles serve to increase the response of male european grape berry moths Eupoecilia ambiguella to their sex pheromone
Journal of Comparative Physiology A-neuroethology Sensory Neural and Behavioral Physiology, 2009Co-Authors: Daniela Schmidtbusser, Martin Von Arx, Patrick M GuerinAbstract:The European grape berry moth is an important pest in vineyards. Males respond to the female-produced sex pheromone released from a piezo nebulizer in a dose- dependent manner in a wind tunnel: <50% arrive at the source at 5-50 pg/min (underdosed), 80% arrive at 100 pg/ min to 10 ng/min (optimal) and <20% arrive at 100 ng/min (overdosed). Males responding to overdosed pheromone show in Xight arrestment at 80 cm from the source. Host plant chemostimuli for Eupoecilia ambiguella increase the responses of males to underdosed and overdosed phero- mone. (Z)-3-hexen-1-ol, (+)-terpinen-4-ol, (E)--caryo- phyllene and methyl salicylate released with the underdosed pheromone cause a signiWcant increase in male E. ambiguella Xying to the source. Time-event analysis indicates a positive correlation between faster activation and probability of source contact by the responding males. The four host plant compounds added to the overdosed pheromone permitted males to take oV faster and with a higher probability of Xying to the source. This suggests that perception of host plant products with the sex pheromone facilitates male E. ambiguella to locate females on host plants, lending credence to the hypothesis that plant prod- ucts can signal rendezvous sites suitable for mating.
Vogelweith Fanny - One of the best experts on this subject based on the ideXlab platform.
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Lobesia botrana as a preferred host of Campoplex capitator, the most occurring larval parasitoid in European vineyards.
HAL CCSD, 2019Co-Authors: Moreau Jérôme, Buffenoir Nina, Thiery Denis, Vogelweith FannyAbstract:6 pagesInternational audienceParasitoids are major biological agents in crop protection, and understanding their preference towards specific host species is a key aspect of successful pest control. In the present study, we have examined the host preferences of the larval parasitoid Campoplex capitator (Hymenoptera: Ichneumonidae), one of the major natural enemies for tortricid grapevine pest populations in European vineyards. Using a test choice between its two main and sympatric hosts, we wanted to determine whether C. capitator females that emerged from Lobesia botrana (Lepidoptera: Tortricidae) also prefer its natal host L. botrana, or Eupoecilia ambiguella (Lepidoptera: Tortricidae) as host; and consequently, if it could be a good candidate as a bio-agent for these species. Our results distinctly showed that naïve C. capitator females preferred L. botrana over E. ambiguella as host, as they directly sought out new L. botrana hosts. Overall, it reveals that C. capitator could be a very efficient parasitoid to control L. botrana populations. Our results might also suggest the importance of natal host in parasitoid host preference, which should be considered in the future when mass-rearing bio-agents
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The relative abundance of hemocyte types in a polyphagous moth larva depends on diet.
'Elsevier BV', 2016Co-Authors: Vogelweith Fanny, Thiery Denis, Moret Yannick, Monceau Karine, Moreau JérômeAbstract:7 pagesInternational audienceHemocytes are crucial cells of the insect immune system because of their involvement in multiple immune responses including coagulation, phagocytosis and encapsulation. There are various types of hemocytes, each having a particular role in immunity, such that variation in their relative abundance affects the outcome of the immune response. This study aims to characterize these various types of hemocytes in larvae of the grapevine pest insect Eupoecilia ambiguella, and to assess variation in their concentration as a function of larval diet and immune challenge. Four types of hemocytes were found in the hemolymph of 5th instar larvae: granulocytes, oenocytoids, plasmatocytes and spherulocytes. We found that the total concentration of hemocytes and the concentration of each hemocyte type varied among diets and in response to the immune challenge. Irrespective of the diet, the concentration of granulocytes increased following a bacterial immune challenge, while the concentration of plasmatocytes and spherulocytes differentially varied between larval diets. The concentration of oenocytoids did not vary among diets before the immune challenge but varied between larval diets in response to the challenge. These results suggest that the resistance of insect larvae to different natural enemies critically depends on the effect of larval diet on the larvae’s investment into the different types of hemocytes
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Food-mediated modulation of immunity in a phytophagous insect: an effect of nutrition rather than parasitic contamination.
'Elsevier BV', 2015Co-Authors: Vogelweith Fanny, Moreau Jérôme, Thiery Denis, Moret YannickAbstract:7 pagesInternational audienceInherent to the cost of immunity, the immune system itself can exhibit tradeoffs between its arms. Phytophagous insects face a wide range of microbial and eukaryotic parasites, each activating different immune pathways that could compromise the activity of the others. Feeding larvae are primarily exposed to microbes, which growth is controlled by antibiotic secondary metabolites produced by the host plant. The resulting variation in abundance of microbes on plants is expected to differentially stimulate the insect antimicrobial immune defenses. Under the above tradeoff hypothesis, stimulation of the insect antimicrobial defenses is expected to compromise immune activity against eukaryote parasites. In the European grape berry moth, Eupoecilia ambiguella, immune effectors directed towards microbes are negatively correlated to those directed towards eukaryotic parasites among host plants. Here, we hypothesize this relationship is caused by a variable control of the microbial community among host plants by their antibiotic metabolites. To test this hypothesis, we first quantified antimicrobial activity in berries of several grape varieties. We then measured immune defenses of E. ambiguella larvae raised on artificial diets in which we mimicked levels of antimicrobial activity of grape berries using tetracycline to control the abundance of growing microbes. Another group of larvae was raised on artificial diets made of berry extracts only to control for the effect of nutrition. We found that controlling microbe abundance with tetracycline in diets did not explain variation in the immune function whereas the presence of berry extracts did. This suggests that variation in immune defenses of E. ambiguella among grape varieties is caused by nutritional difference among host plants rather than microbe abundance. Further study of the effects of berry compounds on larval immune parameters will be needed to explain the observed tradeoff among immune system components
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Defense strategies used by two sympatric vineyard moth pests.
'Elsevier BV', 2014Co-Authors: Vogelweith Fanny, Thiery Denis, Moret Yannick, Colin Eloïse, Motreuil Sébastien, Moreau JérômeAbstract:8 pagesInternational audienceNatural enemies including parasitoids are the major biological cause of mortality among phytophagous insects. In response to parasitism, these insects have evolved a set of defenses to protect themselves, including behavioral, morphological, physiological and immunological barriers. According to life history theory, resources are partitioned to various functions including defense, implying trade-offs among defense mechanisms. In this study we characterized the relative investment in behavioral, physical and immunological defense systems in two sympatric species of Tortricidae (Eupoecilia ambiguella, Lobesia botrana) which are important grapevine moth pests. We also estimated the parasitism by parasitoids in natural populations of both species, to infer the relative success of the investment strategies used by each moth. We demonstrated that larvae invest differently in defense systems according to the species. Relative to L. botrana, E. ambiguella larvae invested more into morphological defenses and less into behavioral defenses, and exhibited lower basal levels of immune defense but strongly responded to immune challenge. L. botrana larvae in a natural population were more heavily parasitized by various parasitoid species than E. ambiguella, suggesting that the efficacy of defense strategies against parasitoids is not equal among species. These results have implications for understanding of regulation in communities, and in the development of biological control strategies for these two grapevine pests
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Immunocompetence increases with larval body size in a phytophagous moth.
'Wiley', 2013Co-Authors: Vogelweith Fanny, Thiery Denis, Moret Yannick, Moreau JérômeAbstract:7 pagesInternational audienceDespite the obvious benefit of an immune system, its efficacy against pathogens and parasites may show great variation among individuals, populations and species. Understanding the causes of this variation is becoming a central theme in ecology. Many biotic and abiotic factors are known to influence immunocompetence (temperature, age, etc.). However, for a given age, size among individuals varies, probably as a result of accumulated resources. Thus, these variable resources could be allocated to immune defence and, consequently, body size may explain part of the variation in immune responsiveness. However, the influence of body size on immune defence is often overlooked. The present study investigates variations in haemocyte count and phenoloxidase activity in larvae of the phytophagous vine moth Eupoecilia ambiguella H¨ubner of the same age, although differing in body size. The measurements of immune function are made both when the insects are immunologically naïve and 24 h after a bacterial immune challenge. The base levels of these immune parameters do not covary with body size in naïve larvae. After the bacterial immune challenge, more haemocytes and phenoloxidase enzyme are mobilized, and the mobilization of these immune effectors is correlated positively with individual body size. Thus, larger larvae exhibit higher immunocompetence than smaller ones, suggesting that smaller larvae might be more vulnerable to infection. These results suggest that body size is probably an underestimated variable, which nevertheless modulates the insect immune system and should thus be considered as a covariate in insect immune system measurement. It is recommended therefore, that body size should be taken into account in ecological immunity studies with insects
Daniela Schmidtbusser - One of the best experts on this subject based on the ideXlab platform.
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host plant volatiles serve to increase the response of male european grape berry moths Eupoecilia ambiguella to their sex pheromone
Journal of Comparative Physiology A-neuroethology Sensory Neural and Behavioral Physiology, 2009Co-Authors: Daniela Schmidtbusser, Martin Von Arx, Patrick M GuerinAbstract:The European grape berry moth is an important pest in vineyards. Males respond to the female-produced sex pheromone released from a piezo nebulizer in a dose- dependent manner in a wind tunnel: <50% arrive at the source at 5-50 pg/min (underdosed), 80% arrive at 100 pg/ min to 10 ng/min (optimal) and <20% arrive at 100 ng/min (overdosed). Males responding to overdosed pheromone show in Xight arrestment at 80 cm from the source. Host plant chemostimuli for Eupoecilia ambiguella increase the responses of males to underdosed and overdosed phero- mone. (Z)-3-hexen-1-ol, (+)-terpinen-4-ol, (E)--caryo- phyllene and methyl salicylate released with the underdosed pheromone cause a signiWcant increase in male E. ambiguella Xying to the source. Time-event analysis indicates a positive correlation between faster activation and probability of source contact by the responding males. The four host plant compounds added to the overdosed pheromone permitted males to take oV faster and with a higher probability of Xying to the source. This suggests that perception of host plant products with the sex pheromone facilitates male E. ambiguella to locate females on host plants, lending credence to the hypothesis that plant prod- ucts can signal rendezvous sites suitable for mating.
Martin Von Arx - One of the best experts on this subject based on the ideXlab platform.
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host plant volatiles serve to increase the response of male european grape berry moths Eupoecilia ambiguella to their sex pheromone
Journal of Comparative Physiology A-neuroethology Sensory Neural and Behavioral Physiology, 2009Co-Authors: Daniela Schmidtbusser, Martin Von Arx, Patrick M GuerinAbstract:The European grape berry moth is an important pest in vineyards. Males respond to the female-produced sex pheromone released from a piezo nebulizer in a dose- dependent manner in a wind tunnel: <50% arrive at the source at 5-50 pg/min (underdosed), 80% arrive at 100 pg/ min to 10 ng/min (optimal) and <20% arrive at 100 ng/min (overdosed). Males responding to overdosed pheromone show in Xight arrestment at 80 cm from the source. Host plant chemostimuli for Eupoecilia ambiguella increase the responses of males to underdosed and overdosed phero- mone. (Z)-3-hexen-1-ol, (+)-terpinen-4-ol, (E)--caryo- phyllene and methyl salicylate released with the underdosed pheromone cause a signiWcant increase in male E. ambiguella Xying to the source. Time-event analysis indicates a positive correlation between faster activation and probability of source contact by the responding males. The four host plant compounds added to the overdosed pheromone permitted males to take oV faster and with a higher probability of Xying to the source. This suggests that perception of host plant products with the sex pheromone facilitates male E. ambiguella to locate females on host plants, lending credence to the hypothesis that plant prod- ucts can signal rendezvous sites suitable for mating.
