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Guerin, Patrick

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

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  • Publication
    Accès libre
    Contact chemostimuli in the mating behaviour of the cattle tick, Boophilus microplus
    (1999)
    de Bruyne, Marien
    ;
    Guerin, Patrick 
    Mating of the cattle tick Boophilus microplus is mediated by chemical stimuli on the cuticle of females. Males are arrested on the dorsum of females attached to the host, frequently sample the substrate, and then tip-over to the ventrally located gonopore. These behaviours are also observed in vitro when males are placed on a small glass bead treated with a female extract. Time spent and tip-over by male ticks on dummies is used in an assay to test the behavioural significance of fractions of the extract. TLC separation yields one apolar fraction that arrests males, though much less so than the whole extract, but lost tip-over behaviour. This apolar fraction contains a series of cholesteryl esters that, when tested individually, show no arrestment activity at levels present in the extract but, when combined, are as active as the fraction. When a small silica column is used for fractionation, all biological activity is reproduced after recombining the fractions. In addition to the early eluting apolar fraction containing cholesteryl esters, a set of highly active more polar fractions is isolated. Electrophysiological recordings from gustatory sensilla on the pedipalps of male B. microplus, which are regularly brought into contact with the cuticle of the female during mating, provide evidence for receptors in two of them responding to the whole extract and to the behaviourally active polar fractions. Mating behaviour involving arrestment and tip-over is clearly initiated by a mixture of chemical stimuli, and tip-over behaviour is associated with the more polar material.
  • Publication
    Accès libre
    Some observations on mating and fertilization in the cattle tick Boophilus microplus
    (1994)
    Falk-Vairant, Jean
    ;
    Guerin, Patrick 
    ;
    de Bruyne, Marien
    ;
    Rohrer, Marcel
  • 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.