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Guerin, Patrick

Nom
Guerin, Patrick
Affiliation principale
Fonction
Ancien.ne collaborateur.trice
Identifiants
https://libra.unine.ch/handle/123456789/310
_
0000-0002-2257-5097

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  • Publication
    Accès libre
    (1S,3S,7R)-3-methyl-α-himachalene from the male sandfly Lutzomyia longipalpis (Diptera: Psychodidae) induces neurophysiological responses and attracts both males and females
    (2005)
    Spiegel, C.N.
    ;
    Jeanbourquin, Philippe 
    ;
    Guerin, Patrick 
    ;
    Hooper, A.M.
    ;
    Claude, S.
    ;
    Tabacchi, Raffaele 
    ;
    Sano, S.
    ;
    Mori, K.
    Lutzomyia longipalpis adult males form leks on or near hosts and release (1S,3S,7R)-3-methyl-α-himachalene from their tergal glands to lure females to the same site for mating and feeding. Here we have examined whether the male-produced attractant could also serve as a male aggregation stimulus. High resolution chiral capillary gas chromatography analysis of male tergal gland extracts, synthetic (1S,3S,7R)-3-methyl-α-himachalene, and a synthetic mixture of all isomers of 3-methyl-α-himachalene, was coupled to electrophysiological recordings from ascoid sensillum receptor cells in antennae of male and female sandflies. Receptor cells of both sexes responded only to the main component of the male tergal gland extract that eluted at the same retention time as (1S,3S,7R)-3-methyl-α-himachalene. Furthermore, of the eight 3-methyl-α-himachalene isomers in the synthetic mixture only the fraction containing (1S,3S,7R)-3-methyl-α-himachalene, co-eluting with an isomer of (1S*,3S*,7S*)-3-methyl-α-himachalene, elicited an electrophysiological response from male and female ascoid sensillum receptor cells. Both males and females flew upwind in a wind tunnel towards a filter paper disk treated with either 4–6 male equivalents of the tergal gland extract, pure (1S,3S,7R)-3-methyl-α-himachalene or the synthetic mixture of eight isomers. This indicates that (1S,3S,7R)-3-methyl-α-himachalene derived from L. longipalpis males may have a dual function in causing male aggregation as well as serving as a sex pheromone for females.
  • Publication
    Accès libre
    Influence of Dose and Ratio of Mixtures of Pheronome Components on the Attraction of the Tropical Bont Tick, Amblyomma Variegatum
    (2000)
    McMahon, Conor
    ;
    Guerin, Patrick 
    The responses of A. variegatum adults to constituents ot 'their aggregation-attraction pheromone presented in an air stream were studied using a locomotion compensator. The responses to vapours from two mixtures were compared, the first a 1:1 mixture of o-nitrophenol and methyl salicylale, the second a four component mixture ® containing o-nitrophenol, methyl salicylale, 2,6 dichlorophenol and phenyl acetaldehyde in the ratio 10:10:2:1, respectively. No difference was found between the kineses responses of A. 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 μg of the main components, but were not attractive at source doses 100 times higher. As with many other arthropods, A. variegatum adults arc 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.
  • Publication
    Accès libre
    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 here. 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 104-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
    Accès libre
    Isolation of 2,6-dichlorophenol from the cattle tick Boophilus microplus: Receptor cell responses but no evidence for a behavioural response
    (1994)
    de Bruyne, Marien
    ;
    Guerin, Patrick 
    2,6-Dichlorophenol, a compound known as a sex pheromone for several metastriate tick species, was isolated from different life-stages of the cattle tick Boophilus microplus. Receptor cells in two wall-pore single-walled sensilla on the tarsus I of male ticks responded to this compound in a dose-dependant manner. Using these receptors as specific detectors for compounds in the effluent of a gas chromatograph, we detected 2,6-dichlorophenol in extracts of females, males, engorged nymphs and larvae of this one-host tick, but not in an extract of eggs. No other components of the extracts elicited responses from these olfactory sensilla. However, male B. microplus were not arrested on a glass bead treated with 2,6-dichlorophenol and placed on a membrane in a host-simulating arena, whereas a bead treated with a female extract did evoke a strong arrestment response. In addition, no odour-conditioned anemotaxis, change in angular velocity or speed of males walking on a locomotion compensator was observed in response to this compound in a conditioned air-stream. We could therefore not establish a role for 2,6-dichlorophenol on its own as a semiochemical in males of this species.