What makes Episyrphus balteatus (Diptera: Syrphidae) oviposit on aphid infested tomato plants?
Verheggen, François ; Capella, Quentin ; Wathelet, Jean-Paul et al
in Communications in Agricultural and Applied Biological Sciences (2008), 73(3), 371-81
Under attack by insect pests, many plant species change their volatile chemical emissions to attract natural enemies. Most of the tomato (Lycopersicon sp., Solanaceae) varieties are subjected to ... [more ▼]
Under attack by insect pests, many plant species change their volatile chemical emissions to attract natural enemies. Most of the tomato (Lycopersicon sp., Solanaceae) varieties are subjected to infestation by molluscs and insects, including the generalist aphid Myzus persicae Sulzer (Homoptera, Aphididae). Episyrphus balteatus De Geer (Diptera: Syrphidae) is a generalist aphid predator that was here observed to lay eggs on M. persicae infested tomato but not on non-infested plants. In order to identify the volatile chemicals that guide the foraging and oviposition behaviour of E. balteatus, we collected and identified volatiles released in the headspace of both aphid infested and uninfested tomato plants by SPME-GC-MS. The identified chemicals were subsequently tested by electroantennography (EAG) on E. balteatus. Monoterpenes and sesquiterpenes were identified, the main volatile chemicals being beta-phellandrene, 2-carene, alpha-phellandrene, 3-carene and o-pinene. Electrical depolarizations were observed for each tested monoterpene, with optimal responses ranging from -0.2 to -0.8 mV. Episyrphus balteatus antennae showed dose-response relationships towards all the active chemicals. (E)-beta-farnesene, the main component of the aphid alarm pheromone, was the only active sesquiterpene, and is presumed to act as an oviposition stimulus for E. balteotus. [less ▲]Detailed reference viewed: 145 (15 ULg)
Discrimination of parasitized aphids by a hoverfly predator: effects on larval performance, foraging, and oviposition behavior
; Verheggen, François ; Francis, Frédéric et al
in Entomologia Experimentalis et Applicata (2008), 128(1), 73-80
The choice of oviposition site by female aphidophagous predators is crucial for offspring performance, especially in hoverflies whose newly hatched larvae are unable to move over large distance. Predator ... [more ▼]
The choice of oviposition site by female aphidophagous predators is crucial for offspring performance, especially in hoverflies whose newly hatched larvae are unable to move over large distance. Predator and parasitoid interactions within the aphidophagous guild are likely to be very important in influencing the choices made by predatory hoverfly females. In the present study, the foraging and oviposition behavior of the aphidophagous hoverfly Episyrphus balteatus DeGeer (Diptera: Syrphidae) was investigated with respect to the parasitized state of its aphid prey, Acyrthosiphon pisum Harris (Homoptera: Aphididae), that were parasitized by Aphidius ervi Haliday (Hymenoptera: Aphidiidae). We also recorded the number of eggs laid by hoverfly females when subjected to parasitized aphids. Furthermore, we studied the influence of being fed with parasitized aphids on hoverfly larval performance. Hoverfly females did not exhibit any preference for plants infested with unparasitized or aphids parasitized for 7 days. On the other hand, plants infested with mummies or exuvia were less attractive for E. balteatus. These results were correlated with (i) the number of eggs laid by E. balteatus females and (ii) larval performance. Thus, our results demonstrate that E. balteatus behavior is affected by parasitoid presence through their exploitation of aphid colonies. Indeed, hoverfly predators select their prey according to the developmental state of the parasitoid larvae. [less ▲]Detailed reference viewed: 67 (8 ULg)
Emission of alarm pheromone in aphids: A non-contagious phenomenon
Verheggen, François ; ; Haubruge, Eric et al
in Journal of Chemical Ecology (2008), 34(9), 1146-1148
In response to attack by natural enemies, most aphid species release an alarm pheromone that causes nearby conspecifics to cease feeding and disperse. The primary component of the alarm pheromone of most ... [more ▼]
In response to attack by natural enemies, most aphid species release an alarm pheromone that causes nearby conspecifics to cease feeding and disperse. The primary component of the alarm pheromone of most species studied is (E)-beta-farnesene. We recently demonstrated that the production and accumulation of (E)-beta-farnesene during development by juvenile aphids is stimulated by exposure to odor cues, most likely by (E)-beta-farnesene emitted by other colony members. Here, we tested whether the release of (E)-beta-farnesene can be triggered by exposure to the alarm pheromone of other individuals, thereby amplifying the signal. Such contagious emission might be adaptive under some conditions because the amount of (E)-beta-farnesene released by a single aphid may not be sufficient to alert an appropriate number of individuals of the colony to the presence of a potential threat. By using a push-pull headspace collection system, we quantified (E)-beta-farnesene released from Acyrthosiphon pisum aphids exposed to conspecific alarm signals. Typical avoidance behavior was observed following exposure to (E)-beta-farnesene (i.e., aphids ceased feeding and dropped from host-plant); however, no increase in alarm pheromone amount was detected, suggesting that contagious release of (E)-beta-farnesene does not occur. [less ▲]Detailed reference viewed: 55 (8 ULg)
Mothflies (Diptera : Psychodidae) in hospitals: A guide to their identification and methods for their control
Verheggen, François ; Mignon, Jacques ; Louis, Josiane et al
in Acta Clinica Belgica (2008), 63(4), 251-255
Repeated observation of "mothflies" at CHU Brugmann (Horta site hospital in Brussels) is not an isolated incident. Many public buildings have been infested by these Diptera of the Psychodidae Family ... [more ▼]
Repeated observation of "mothflies" at CHU Brugmann (Horta site hospital in Brussels) is not an isolated incident. Many public buildings have been infested by these Diptera of the Psychodidae Family. Although the species currently seen in Belgium is not a danger to human health, any infestation should be swiftly eradicated so as to limit the risks of a massive proliferation, source of hygiene problems and of potential bacterial dissemination. A good knowledge of adult and larval biology allows the potential sites of infestation to be quickly identified. The method to be envisaged to solve the problem will combine different approaches such as removing the risk factors (decomposing organic matter), monitoring egg-laying sites, applying caustic soda-based products and possibly treating with insecticide. [less ▲]Detailed reference viewed: 59 (8 ULg)
Aphid and plant volatiles induce oviposition in an aphidophagous hoverfly
Verheggen, François ; ; et al
in Journal of Chemical Ecology (2008), 34(3), 301-307
Episyrphus balteatus DeGeer (Diptera, Syrphidae) is an abundant and efficient aphid-specific predator. We tested the electroantennographic (EAG) response of this syrphid fly to the common aphid alarm ... [more ▼]
Episyrphus balteatus DeGeer (Diptera, Syrphidae) is an abundant and efficient aphid-specific predator. We tested the electroantennographic (EAG) response of this syrphid fly to the common aphid alarm pheromone, (E)-beta-farnesene (E beta F), and to several plant volatiles, including terpenoids (mono- and sesquiterpenes) and green leaf volatiles (C6 and C9 alcohols and aldehydes). Monoterpenes evoked significant EAG responses, whereas sesquiterpenes were inactive, except for the aphid alarm pheromone (E beta F). The most pronounced antennal responses were elicited by six and nine carbon green leaf alcohols and aldehydes [i.e., (Z)-3-hexenol, (E)-2-hexenol, (E)-2-hexenal, and hexanal]. To investigate the behavioral activity of some of these EAG-active compounds, E. balteatus females were exposed to R-(+)-limonene (monoterpene), (Z)-3-hexenol (green leaf alcohol), and E beta F (sesquiterpene, common aphid alarm pheromone). A single E. balteatus gravid female was exposed for 10 min to an aphid-free Vicia faba plant that was co-located with a semiochemical dispenser. Without additional semiochemical, hoverfly females were not attracted to this plant, and no oviposition was observed. The monoterpene R-(+)-limonene did not affect the females' foraging behavior, whereas (Z)-3-hexenol and E beta F increased the time of flight and acceptance of the host plant. Moreover, these two chemicals induced oviposition on aphid-free plants, suggesting that selection of the oviposition site by predatory hoverflies relies on the perception of a volatile blend composed of prey pheromone and typical plant green leaf volatiles. [less ▲]Detailed reference viewed: 56 (17 ULg)
Impact of aphid colony size and associated induced plant volatiles on searching and oviposition behaviour of a predatory hoverfly
; Verheggen, François ; Francis, Frédéric et al
in Belgian Journal of Entomology (2008), 10Detailed reference viewed: 59 (10 ULg)
Identification of aphid salivary proteins: a proteomic investigation of Myzus persicae.
Harmel, Nicolas ; ; et al
in Insect Molecular Biology (2008), 17(2), 165-74
The role of insect saliva in the first contact between an insect and a plant is crucial during feeding. Some elicitors, particularly in insect regurgitants, have been identified as inducing plant defence ... [more ▼]
The role of insect saliva in the first contact between an insect and a plant is crucial during feeding. Some elicitors, particularly in insect regurgitants, have been identified as inducing plant defence reactions. Here, we focused on the salivary proteome of the green peach aphid, Myzus persicae. Proteins were either directly in-solution digested or were separated by 2D SDS-PAGE before trypsin digestion. Resulting peptides were then identified by mass spectrometry coupled with database investigations. A homemade database was constituted of expressed sequence tags from the pea aphid Acyrtosiphon pisum and M. persicae. The databases were used to identify proteins related to M. persicae with a nonsequenced genome. This procedure enabled us to discover glucose oxidase, glucose dehydrogenase, NADH dehydrogenase, alpha-glucosidase and alpha-amylase in M. persicae saliva. The presence of these enzymes is discussed in terms of plant-aphid interactions. [less ▲]Detailed reference viewed: 85 (28 ULg)
Purification and characterization of a carboxylesterase involved in malathion-specific resistance from Tribolium castaneum (Coleoptera: Tenebrionidae).
; Haubruge, Eric ; et al
in Insect Biochemistry and Molecular Biology (2008), 32Detailed reference viewed: 33 (2 ULg)
Chemical ecology in forensic entomology: Investigation of volatile infochemicals from pig cadaver on necrophagous insect behaviour
Dekeirsschieter, Jessica ; Verheggen, François ; Francis, Frédéric et al
Poster (2008)Detailed reference viewed: 58 (3 ULg)
Aphid – ant mutualism : How do aphids focus ant foraging ?
Verheggen, François ; ; et al
Poster (2008)Detailed reference viewed: 18 (3 ULg)
Role of prey–host plant associations on Harmonia axyridis and Episyrphus balteatus field distribution and efficiency.
; Haubruge, Eric ; Francis, Frédéric
in Entomologia Experimentalis et Applicata (2008), 128Detailed reference viewed: 15 (0 ULg)
Emission of alarm pheromone in aphids: A contagious phenomenon?
Verheggen, François ; ; Francis, Frédéric et al
Poster (2008)Detailed reference viewed: 15 (1 ULg)
Ophioglossum polyphyllum A. Braun in Seub. (Ophioglossaceae, Pteridophyta), a rare potherb in south central Tibet (T.A.R., P.R.China)
Lognay, Georges ; Haubruge, Eric ; et al
in Geo-Eco-Trop (2008), 32Detailed reference viewed: 47 (4 ULg)
Does one observe the honeybee colony collapse disorder in Europe ?
Nguyen, Bach Kim ; Haubruge, Eric
Conference given outside the academic context (2007)Detailed reference viewed: 30 (6 ULg)
Etat sanitaire des ruchers en Région wallonne (Belgique)
Mignon, Jacques ; Nguyen, Bach Kim ; et al
Poster (2007, November)Detailed reference viewed: 25 (0 ULg)
Le dépérissement de l'abeille domestique: analyse multifactorielle réalisée en Belgique
Nguyen, Bach Kim ; Mignon, Jacques ; Haubruge, Eric
Poster (2007, November)Detailed reference viewed: 54 (10 ULg)
Proteome analysis of the bovine milk fat globule : enhancement in the membrane purification.
Vanderghem, Caroline ; Blecker, Christophe ; Danthine, Sabine et al
Poster (2007, October 11)Detailed reference viewed: 15 (1 ULg)
Development and validation of a multi-residue method for pesticide determination in honey using on-column liquid-liquid extraction and liquid chromatography-tandem mass spectrometry
PIRARD, Catherine ; Widart, Joëlle ; Nguyen, Bach Kim et al
in Journal of Chromatography. A (2007), 1152(1-2), 116-123
We report on the development and validation under ISO 17025 criteria of a multi-residue confirmatory method to identify and quantify 17 widely chemically different pesticides (insecticides: Carbofuran ... [more ▼]
We report on the development and validation under ISO 17025 criteria of a multi-residue confirmatory method to identify and quantify 17 widely chemically different pesticides (insecticides: Carbofuran, Methiocarb, Pirimicarb, Dimethoate, Fipronil, Imidacloprid; herbicides: Amidosulfuron, Rimsulfuron, Atrazine, Simazine, Chloroturon, Linuron, Isoxaflutole, Metosulam; fungicides: Diethofencarb) and 2 metabolites (Methiocarb sulfoxide and 2-Hydroxytertbutylazine) in honey. This method is based on an on-column liquid liquid extraction (OCLLE) using diatomaceous earth as inert solid support and liquid chromatography (LC) coupled to mass spectrometry (MS) operating in tandem mode (MS/MS). Method specificity is ensured by checking retention time and theoretical ratio between two transitions from a single precursor ion. Linearity is demonstrated all along the range of concentration that was investigated, from 0.1 to 20 ng g(-1) raw honey, with correlation coefficients ranging from 0.921 to 0.999, depending on chemicals. Recovery rates obtained on home-made quality control samples are between 71 and 90%, well above the range defined by the EC/657/2002 document, but in the range we had fixed to ensure proper quantification, as levels found in real samples could not be corrected for recovery rates. Reproducibility is found to be between 8 and 27%. Calculated CC alpha and CC beta (0.0002-0.943 mg g(-1) for CC alpha, and 0.0002-1.232 ng g(-1) for CCP) show the good sensitivity attained by this rnulti-residue analytical method. The robustness of the method has been tested in analyzing more than 100 raw honey samples collected from different areas in Belgium, as well as some wax and bee samples, with a slightly adapted procedure. (C) 2007 Elsevier B.V. All rights reserved. [less ▲]Detailed reference viewed: 166 (33 ULg)
Proteone analysis of the bovine milk fat globule : enhancement in the membrane purification.
Vanderghem, Caroline ; Blecker, Christophe ; Danthine, Sabine et al
Poster (2007, May 15)Detailed reference viewed: 27 (2 ULg)