Vignette d'image

Guerin, Patrick

Nom
Guerin, Patrick
Affiliation principale
Site web
Fonction
Professeur associé
Email
patrick.guerin@unine.ch
Identifiants
https://libra.unine.ch/handle/123456789/310

Résultat de la recherche

Filtres

41
111
4
31
Réinitialiser les filtres

Paramètres

Voici les éléments 1 - 4 sur 4
  • Publication
    Métadonnées seulement
    In vitro assays for repellents and deterrents for ticks: differing effects of products when tested with attractant or arrestment stimuli
    (2003)
    McMahon, Conor
    ;
    Kroeber, Thomas 
    ;
    Guerin, Patrick 
    Most in vivo and in vitro tests with repellents or deterrents against ticks have not considered which sensory channel is being targeted. We have recorded the responses of two hard tick species (Acari: Ixodidae) in vitro to determine if such products can disrupt the perception of an attractant in a repellent assay or the perception of an arrestment stimulus in a deterrent assay. Ethyl butylacetylaminopropionate (EBAAP), N,N-diethyl-methyl-benzamide (deet), permethrin and indalone were chosen to test their capacity to inhibit the attraction of Amblyomma variegatum Fabricius to its aggregation-attachment pheromone. Vapours of each test product plus those from a synthetic blend of the pheromone were delivered to the walking tick in an air stream on a locomotion compensator. Neither EBAAP, deet, permethrin nor indalone could inhibit attraction of A. variegatum even when each of the test products was delivered at 10(6) times the pheromone. Indalone did decrease the attraction of A. variegatum to the pheromone and induced repulsion of A. variegatum when presented on its own in the air stream. The effect of permethrin, a sodium channel blocker, was also tested in a deterrent assay measuring the arrestment of Ixodes ricinus (L.) adults on its own faeces and faecal constituents. Permethrin deterred arrestment at doses of 670 fg/cm(2) to 67 ng/cm(2), i.e. at levels five times lower than the dose of chemostimuli present in the arrestment stimulus. This sensitivity to permethrin suggests that it acts via the contact chemoreception channel.
  • Publication
    Métadonnées seulement
    Responses of the tropical bont tick, Amblyomma variegatum (Fabricius), to its aggregation-attachment pheromone presented in an air stream on a servosphere
    (2000)
    McMahon, Conor
    ;
    Guerin, Patrick 
    Male Amblyomma variegatum ticks feeding on a host release a mixture of o-nitrophenol and methyl salicylate which serves to attract conspecifics. The behavioural responses of A. variegatum on a servosphere to these volatiles presented in an air stream are detailed hers. In still air, ticks walked on all eight legs, but with long halts. In contrast, the air stream caused continuous walking and induced a reaching response where the forelegs actively sampled the air. Such reaching increased the angular velocity and reduced walking speed, effects that were amplified in the presence of vapours from o-nitrophenol and methyl salicylate in the air flowing over the ticks. Vapour from a 1:1 mixture of o-nitrophenol and methyl salicylate was attractive over a 10(4)-fold concentration range providing an increase in upwind displacement of 20-40%, significantly higher than the natural ratio where o-nitrophenol vapour predominates. Although the responses to o-nitrophenol vapour were variable when presented alone, this chemical was consistently attractive when delivered with steer hair odour - unattractive on its own. Moreover, the upwind walk to this combination did not cause a change in speed or angular velocity. This supports the hypothesis that the response to the pheromone is enhanced by host odour.
  • Publication
    Métadonnées seulement
    Influence of dose and ratio of mixtures of pheromone components on the attraction of the tropical bont tick, Amblyomma variegatum
    (: Slovak Academy Sciences Institute Zoology, 1999)
    McMahon, Conor
    ;
    Guerin, Patrick 
    ;
    Kazimirova, M
    ;
    Labuda, M
    ;
    Nuttall, Patricia
    The responses of Amblyomma variegatum adults to constituents of their aggregation-attraction pheromone presented in an air stream were studied using a locomotion compensator. Behaviours to vapours from two mixtures were compared, the first a 1:1 mixture of o-nitrophenol and methyl salicylate, the second a four component mixture (R) containing o-nitrophenol, methyl salicylate, 2,6 dichlorophenol and phenyl acetaldehyde in the ratio 10:10:2:1, respectively No difference was found between the kineses responses ofA. variegatum adults for either mixture: both elicited an increase in angular velocity and a reduction in speed, Moreover; attraction to vapours of either mixture was reduced significantly as the source dose was increased: both mixtures were good attractants at a source dose of 10 mug of the main components, but were not attractive at source doses 100 times higher. As with many other arthropods, A. variegatum adults are responsive to the ratio, as well as to the dose, of constituents in an attractant mix. We suggest that the quantity and ratios of compounds in attractive mixtures released from commercial dispensers should be measured before use in any control programme.