Aphid density influences oviposition behaviour and larval performance in predatory hoverfly

Conference (2007)

Oviposition site discrimination by generalist hoverfly predator: effect of parasitized aphids (Homoptera : aphididae)

Poster (2007)

How does the age of hoverfly females affect their reproduction?

Conference (2007)

How does the age of hoverfly females affect their reproduction?

in Communications in Agricultural and Applied Biological Sciences (2007), 72(3),

Perception of aphid infested tomato plant volatiles by the predator Episyrphus balteatus

Poster (2006)

Contribution à l'étude des relations tritrophiques entre la tomate (Lycopersicon esculentum Miller), le puceron vert du pêcher (Myzus persicae Sulzer) et le syrphe ceinturé (Episyrphus balteatus DeGeer)

Master of advanced studies dissertation (2005)

Is the (E)-ß-farnesene only volatile terpenoid in aphids?

in Journal of Applied Entomology (2005), 129

Herbivore insects use a broad range of chemical cues to locate their host to feed or to oviposit. Whether several plant volatiles are effective allelochemicals for insects, the latter also emit molecules ... [more ▼]

Herbivore insects use a broad range of chemical cues to locate their host to feed or to oviposit. Whether several plant volatiles are effective allelochemicals for insects, the latter also emit molecules which have infochemical role. The (E)-beta-farnesene (EBF) is a well-known aphid alarm pheromone commonly found in all previously tested species. Analysis of the released molecules from 23 aphid species, mainly collected on their natural host plant from May to July, was performed by gas chromatography–mass spectrometry. While EBF was identified as the main volatile substance in 16 species, alone or associated with other molecules, the alarm pheromone was only a minor component of the volatile molecule pattern of five other species. Moreover, two species, Euceraphis punctipennis and Drepanosiphum platanoides, did not release EBF at all but other terpenes were identified. This original observation raised the question on the utility and the source of the non-EBF volatiles. Are these potential infochemical substances produced by the aphid or only absorbed from the host plant? Here we determined that terpenes released by insects were not only provided by the host plants. Indeed, Megoura viciae emitted additional molecules than the ones from several aphid species reared on the same host plant. Moreover, no systematic relation between the feeding behaviour of the aphid species and the volatile releases was observed. Aphid terpene composition and proportion would provide reliable cues to identify the emitting organism, plant or insect. The next step of this work will be to determine the infochemical role of terpenes found in the range of tested aphid samples to better understand the relations between the different tritrophic levels. [less ▲]

Perception of aphid infested tomato plant volatiles by the predator Episyrphus balteatus

in Communications in Agricultural and Applied Biological Sciences (2005)

In a tritrophic interaction including tomato plant (Lycopersicon esculentum Miller), the herbivore Myzus persicae (Sulzer) and the predator Episyrphus balteatus (De Geer), the perception of the tomato ... [more ▼]

In a tritrophic interaction including tomato plant (Lycopersicon esculentum Miller), the herbivore Myzus persicae (Sulzer) and the predator Episyrphus balteatus (De Geer), the perception of the tomato plants produced volatile organic compounds (VOC) by Episyrphus balteatus is investigated. In a first step, an odour sampling device has been set up aiming the headspace collection of the tomato plant VOC and their adsorption on Tenax adsorbent cartridges (Supelco®). Following desorption is held using a thermodesorption injector (Gerstel®) coupled with GC-MS. Intact and aphid infested plants are studied for their VOC emissions, as well as the comparison of the VOC emission of different tomato cultivars. These VOC consist mainly in mono- and sesquiterpenes (such as - and -pinene ; -humulene ; …) as well as in C6-volatiles like hexenal in case of infestation by herbivores Once the tomato plants VOC identified and quantified, they are tested for their perception by Episyrphus balteatus using electroantennography (EAG). Accordingly, an EAG device has been installed and configured for the study of VOC using Diptera antennas. The monoterpenes limonene and linalool showed high EAG activity whereas other terpenes like cymene seem to be inactive. [less ▲]

Electrophysiological and behavioural study of some secondary metabolites fromTribolium confusum (Du Val) (Coleoptera: Tenebrionidae)

Master's dissertation (2003)