Aggregation pheromones in 2 Australian hard ticks, Ixodes holocyclus and Aponomma concolor.

The presence of an aggregation pheromone has been demonstrated for the first time in indigenous Australian ticks. Filter paper discs exposed to either Australian paralysis ticks Ixodes holocyclus or echidna ticks Aponomma concolor showed inter-sex or intra-sex attraction for ticks of their own species. Nymphal exuviae of Ap, concolor were highly attractive to adult ticks. Discs were significantly attractive to I. holocyclus at distances up to 80 cm.