A comparison of the attraction of nymphs and adults of the ticks Amblyomma hebraeum and A. variegatum to carbon dioxide and the male-produced aggregation-attachment pheromone.

The attraction of nymphs of the ticks Amblyomma hebraeum and A. variegatum to CO2 alone and CO2 together with the male-produced aggregation-attachment pheromone (AAP) was investigated. Matching experiments on the attraction of the adults of the two species were run for comparison. Nymphs of A. hebraeum were strongly attracted to sources of CO2 and CO2/AAP at distances of 10 and 15 m. At distances of 20 and 25 m significantly more nymphs were attracted to CO2/AAP than to CO2 alone. Adults of A. hebraeum were not attracted to CO2 alone at any distance; these ticks were attracted to CO2 and AAP together for distances of up to 25 m. The patterns of attraction of nymphs and adults of A. variegatum at 10 m were similar to those recorded in A. hebraeum.