Investigation into the participation of male pheromones of Rhipicephalus evertsi evertsi during infestation.

It was shown in this study that Rhipicephalus evertsi evertsi males emit pheromones in the preparasitic as well as in the parasitic phases. Conspecific unengorged male and female images exhibited a high response to water-soluble volatiles collected from unengorged males. A vigorous assembly of unfed female R. evertsi evertsi occurred on filter paper discs which had been in contact with either unfed or 5- and 9-day fed males. Progressively increasing percentages of conspecific unengorged males reacted to organic soluble volatiles obtained from 5- and 9-day fed males as well as to hexane washings of intact males which had fed for 9 days. It is concluded that R. evertsi evertsi males participate not only as pheromone receptive, but also as pheromone emitting, partners in the intraspecific communication of this tick species.