Occurrence of sex attractant pheromone, 2,6-dichlorophenol, in relation to age and feeding in American dog tick,Dermacentor variabilis (say) (Acari:Ixodidae).

No detectable sex pheromone, 2,6-dichlorophenol (2,6-DCP), was found inDermacentor variabilis engorged nymphs, teneral females, replete females, or unfed males. The amount of 2,6-DCP present in unfed females of different ages was extremely variable; no relationship between age and 2,6-DCP content in these unfed females was observed. Partially fed virgin females had less 2,6-DCP than unfed females, but there was no change in pheromone content during the course of feeding. Sex pheromone was also found in partially fed males.