Michel Renou - Academia.edu (original) (raw)

Papers by Michel Renou

Frontiers in Physiology

Olfaction is an essential sensory modality for insects and their olfactory environment is mostly ... more Olfaction is an essential sensory modality for insects and their olfactory environment is mostly made up of plant-emitted volatiles. The terrestrial vegetation produces an amazing diversity of volatile compounds, which are then transported, mixed, and degraded in the atmosphere. Each insect species expresses a set of olfactory receptors that bind part of the volatile compounds present in its habitat. Insect odorscapes are thus defined as species-specific olfactory spaces, dependent on the local habitat, and dynamic in time. Manipulations of pest-insect odorscapes are a promising approach to answer the strong demand for pesticidefree plant-protection strategies. Moreover, understanding their olfactory environment becomes a major concern in the context of global change and environmental stresses to insect populations. A considerable amount of information is available on the identity of volatiles mediating biotic interactions that involve insects. However, in the large body of research devoted to understanding how insects use olfaction to locate resources, an integrative vision of the olfactory environment has rarely been reached. This article aims to better apprehend the nature of the insect odorscape and its importance to insect behavioral ecology by reviewing the literature specific to different disciplines from plant ecophysiology to insect neuroethology. First, we discuss the determinants of odorscape composition, from the production of volatiles by plants (section "Plant Metabolism and Volatile Emissions") to their filtering during detection by the olfactory system of insects (section "Insect Olfaction: How Volatile Plant Compounds Are Encoded and Integrated by the Olfactory System"). We then summarize the physical and chemical processes by which volatile chemicals distribute in space (section "Transportation of Volatile Plant Compounds and Spatial Aspects of the Odorscape") and time (section "Temporal Aspects: The Dynamics of the Odorscape") in the atmosphere. The following sections consider the ecological importance of background odors in odorscapes and how insects adapt to their olfactory environment. Habitat provides an odor background and a sensory context that modulate the responses of insects to pheromones and other olfactory signals (section "Ecological Importance of Odorscapes"). In addition, insects do not respond inflexibly to single elements in their odorscape but integrate several components of their environment (section "Plasticity and Adaptation to Complex and Variable Odorscapes"). We finally discuss existing methods of odorscape manipulation for sustainable pest insect control and potential future developments in the context of agroecology (section "Odorscapes in Plant Protection and Agroecology").

Comptes Rendus De L Academie Des Sciences Serie 3 Sciences De La Vie, 1991

Journal of Chemical Ecology, Dec 1, 1994

The trans-and cis-fZ)-c~-bisabolene epoxides (trans-and cis-(Z)-czBE) are the main components of ... more The trans-and cis-fZ)-c~-bisabolene epoxides (trans-and cis-(Z)-czBE) are the main components of the male sex pheromone in Ne-ara viridula. The role of the cis isomer and the importance of the cis/trans proportion lk~r the activity and the specificity of the pheromone are not clearly elucidated and were studied here. lnterindividual variation of the eis/trans proportion produced by males was studied by individual hexanic extracts in two strains originating fn'~m the south of France (SF) and French West Indies (FWI). The trans isomer composed 42-82% of bisabolene epoxides in SF males and 74-94% of bisabolene epoxides in FWI males. Means (4-SD) significantly differ between SF (62.8% +_ 8.4} and FWI (82.4% 4-5.9) males in spite of this interindividual variation. Different isomers of bisabolene epoxide were synthesized and their EAG activity on female antennae was compared. Racemic trans-and cis-(Z)-czBE elicited low EAGs, not different from the nonnatural trans and cis (E)-o~BE that were inactive on behavior. Behavioral tests revealed that racemic trans-and cis-(Z)-etBE attracted 45% (P < 0.05) and 25% (P < 0.05) of females, respectively. The same levels of attraction were obtained with (-) enantiomers of trans-and cis-(Z)-czBE, which attracted 40% (P < 0.05) and 20% (P > 0.05) of the females, respectively. Binary blends containing 75/25. 50/50, and 25/75 proportions of cis/trans isomers were more attractive than trans-(Z)-czBE alone and response of females to the 25% cis/ 75% trans blend was significantly more important than the response to trans-*To whom correspondence should be addressed. 3133 (X)98-O3311941121<X)-3133~)7.0010 r< 19114 Plenulll Publishing {'tll'l~lflliillll 3134 BREZOT ET AL, isomer alone (P < 0~05). The importance of the cis/trans proportion in relation with the specificity of the male pheromone is discussed.

Zeitschrift für Angewandte Entomologie, 1980

... echantillons solides MS-41 (D~SCOINS et GALLOIS 1979) ou sur colonne capillaire de verre, sur... more ... echantillons solides MS-41 (D~SCOINS et GALLOIS 1979) ou sur colonne capillaire de verre, sur Girdel 300 muni d'un injecteur de Ross. ... pour l'analyse par couplage GUMS en impact Clectronique et ionisation chimique sur un systhe Riber muni d'un dispositif de traitement de ...

Pesticide Biochemistry and Physiology

Biosystems, 2015

Insects communicating with pheromones are confronted with an olfactory environment featuring a di... more Insects communicating with pheromones are confronted with an olfactory environment featuring a diversity of volatile organic compounds from plant origin. These volatiles constitute a rich and fluctuant background from which the information carried by the pheromone signal must be extracted. Thus, the pheromone receptor neurons must encode into spike trains the quality, intensity and temporal characteristics of the signal that are determinant to the recognition and localization of a conspecific female. We recorded and analyzed the responses of the pheromone olfactory receptor neurons of male moths to sex pheromone in different odor background conditions. We show that in spite of the narrow chemical tuning of the pheromone receptor neurons, the sensory input can be altered by odorant background.

Frontiers in Physiology, 2015

Male moths rely on olfactory cues to find females for reproduction. Males also use volatile plant... more Male moths rely on olfactory cues to find females for reproduction. Males also use volatile plant compounds (VPCs) to find food sources and might use host-plant odor cues to identify the habitat of calling females. Both the sex pheromone released by conspecific females and VPCs trigger well-described oriented flight behavior toward the odor source. Whereas detection and central processing of pheromones and VPCs have been thought for a long time to be highly separated from each other, recent studies have shown that interactions of both types of odors occur already early at the periphery of the olfactory pathway. Here we show that detection and early processing of VPCs and pheromone can overlap between the two subsystems. Using complementary approaches, i.e., single-sensillum recording of olfactory receptor neurons, in vivo calcium imaging in the antennal lobe, intracellular recordings of neurons in the macroglomerular complex (MGC) and flight tracking in a wind tunnel, we show that some plant odorants alone, such as heptanal, activate the pheromone-specific pathway in male Agrotis ipsilon at peripheral and central levels. To our knowledge, this is the first report of a plant odorant with no chemical similarity to the molecular structure of the pheromone, acting as a partial agonist of a moth sex pheromone.

Journal of chemical ecology, 2001

The behavioral activity of some trifluoromethyl ketones (TFMKs) as inhibitors of the pheromone ac... more The behavioral activity of some trifluoromethyl ketones (TFMKs) as inhibitors of the pheromone activity of the corn stalk borer Sesamia nonagrioides (Lef.) (Lepidoptera: Noctuidae) is reported. The most closely-related analogue to the pheromone tested, (Z)-11-hexadecenyl trifluoromethyl ketone (Z11-16:TFMK), elicited a significant decrease in the number of male catches in traps baited with mixtures with the pheromone in 1:1 and 10:1 ratios in comparison to the pheromone alone. The E isomer of the analogue as well as two highly hydrated ketones, 3-octylthio-1,1,1-trifluoropropan-2-one (OTFP) and 1,1-difluoropentadecyl trifluoromethyl ketone, were inactive. Conversely, the saturated TFMKs n-dodecyl trifluoromethyl ketone and, particularly, n-hexadecyl trifluoromethyl ketone induced a synergistic effect when mixed with the synthetic pheromone in 10:1 ratio. However, in a wind tunnel these chemicals did not elicit any differential effect on flying moths attracted to a source containing ...

Die Pharmazie, 1999

This study describes the isolation and identification of several constituents from Ipomoea pes-ca... more This study describes the isolation and identification of several constituents from Ipomoea pes-caprae (L.) R. Br., a medicinal plant frequently employed in folk medicine of many countries as a remedy against several diseases, including inflammation and pain. Our results demonstrate that some of these compounds, such as glochidone, betulinic acid, alpha- and beta-amyrin acetate, isoquercitrin, etc. showed pronounced antinociceptive properties in the writhing test and formalin test in mice. These data confirm our previous work concerning the antinociceptive action of the hydroalcoholic extract of I. pes-caprae and justify, at least in part, the popular use of this plant for the treatment of dolorous processes.

Frontiers in cellular neuroscience, 2012

The monitoring programme for non-radiation environmental parameters at CERN comprises both the co... more The monitoring programme for non-radiation environmental parameters at CERN comprises both the control of air and water released from CERN installations (emissions), as well as monitoring of air quality at places close to the CERN sites and checks of water quality in rivers receiving water from CERN (immissions). Concentrations of selected noxious gases (NO, NO2 and O3) were measured in the LEP ventilation outlets PA-1 and PA-5 till the final shutdown of the collider in November 2000. The measurements continued at two off-site monitoring stations in Meyrin and Cessy placed in the vicinity of the two ventilation outlets. The control of released water includes continuous monitoring of pH and temperature at six CERN water outlets. Regular measurements of pH, temperature, conductivity and concentration of dissolved oxygen were performed in the water of the rivers Nant d’Avril and Le Lion as well as in the water of the streams around the seven LEP islands PA-2 − PA-8. Streams receiving w...