ISOLATION OF 2,6-DICHLOROPHENOL FROM THE CATTLE TICK BOOPHILUS-MICROPLUS - RECEPTOR CELL RESPONSES BUT NO EVIDENCE FOR A BEHAVIORAL-RESPONSE

2,6-Dichlorophenol, a compound known as a sex pheromone for several me tastriate tick species, was isolated from different life-stages of the cattle tick Boophilus microplus. Receptor cells in two wall-pore sing le-walled sensilla on the tarsus I of male ticks responded to this com pound in a dose-dependant manner. Using these receptors as specific de tectors for compounds in the effluent of a gas chromatograph, we detec ted 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 ot her components of the extracts elicited responses from these olfactory sensilla. However, male B. microplus were not arrested on a glass bea d treated with 2,6-dichlorophenol and placed on a membrane in a host-s imulating arena, whereas a bead treated with a female extract did evok e a strong arrestment response. In addition, no odour-conditioned anem otaxis, change in angular velocity or speed of males walking on a loco motion compensator was observed in response to this compound in a cond itioned air-stream. We could therefore not establish a role for 2,6-di chlorophenol on its own as a semiochemical in males of this species.