Effect of attractant sex pheromone on immature larval stages of ixodid tick species

Attractant sex pheromone (ASP) 2,6-dichloro phenol was used in the current study to evaluate the percentage attraction and the behavioural responses of the five ixodid tick species namely Rhipicephalus sanguineus, Rhipicephalus microplus (Boophilus microplus), Haemaphysalis bispinosa, Rhipicephalus haemaphysaloides and Hyalomma marginatum using petridish bioassay. Two concentrations of 2,6-DCP (0.1 M and 0.05 M) was used for the larval stages of all five ixodid tick species of which 0.1 M concentration was found to have maximum attraction. Trials with 0.1 M ASP revealed highest per cent of attraction in R. sanguineus larvae (71 %) followed by H. bispinosa (55 %) and R. microplus (55 %). With 0.1 M ASP R. haemaphysaloides and H. marginatum showed least attraction (39 % each). However the per cent of attraction of R. haemaphysaloides was higher (46 %) with 0.05 M ASP. Statistical analysis revealed a highly significant difference in per cent of attraction between the different tick larvae using 0.05 and 0.1 M ASP. The larvae also exhibited behavioural responses such as feeding, probing, resting and questing posture.