title: What attracts larval Ixodes hirsti (Acari: Ixodidae) to their host?
abstract: Ticks are extremely susceptible to desiccation when not on a host. Even though Ixodid ticks are capable of surviving extreme conditions, it is in the best interest of the tick to locate a host quickly. The aim of this study was to determine the host stimuli used by larval Ixodes hirsti for location of their passerine host. Additionally, we recorded the average questing height of larval ticks. We found that I. hirsti larvae were attracted to shade and heat, while they were unresponsive to host odor and CO2. The average questing height was 12.4 cm. Sensitivity to both shade and heat will aid larval I. hirsti in their ambush strategy to find a host. Preference for shaded environments and a low questing height favors the occurrence of larvae in high humidity environments. Such moist environments indirectly increase lifespan duration because of reduced movement for water sorption, and increase tick questing which is limited by vertical mobility. Additionally, larval ticks with a low questing height have a higher chance of encountering a ground foraging passerine host.
authors.affiliation: School of Biological Sciences, Flinders University, GPO Box 2100, Adelaide, SA, 5001, Australia.
authors.forename: Margot
authors.initials: M
authors.lastname: Oorebeek
authors.forename: Robert
authors.initials: R
authors.lastname: Sharrad
authors.forename: Sonia
authors.initials: S
authors.lastname: Kleindorfer
mesh_terms: D000818:Animals; D002245:Carbon Dioxide / Q000494:pharmacology; D002630:Chemotactic Factors / Q000494:pharmacology; D003624:Darkness; D006358:Hot Temperature; D018884:Ixodes / Q000502:physiology*; D007814:Larva / Q000502:physiology; D009812:Odorants; D046109:Passeriformes / Q000469:parasitology*
chemical_list: D002630:Chemotactic Factors; D002245:Carbon Dioxide