Efficacy of the transfluthrin-based personal insect repellent kit (PIRK) against the ixodid ticks Ixode s scapularis, Amblyomma americanum and Dermacentor variabilis .

An assay series was performed to assess the contact and spatial efficacy of the Personal Insect Repellent Kit (PIRK) against three species of ixodid ticks. The PIRK, a portable, passive device comprised of an inert physical substrate incorporated with the active ingredient (AI) transfluthrin (TF), has demonstrated spatial efficacy against flying insects, including three species of mosquitoes, sand flies and stable flies. The device is the only TF end-use product registered with the EPA. Here we report the first studies to explore potential of the PIRK to control , and . Dose-response assays confirmed toxicity of TF to larvae of all species in the μg/ml range following a 30-min exposure period. Nymphs and adults exhibited irritancy and avoidance behaviors on contact with the PIRK. Greater than 90% knockdown (KD) of nymphs and adults was observed after a 10-s exposure, and of nymphs and adults after 10-s and 120-s exposure, respectively. Additionally, greater than 90% mortality was observed in nymphs and adults after 10-s and 40-s exposure, respectively. In spatial assays, the PIRK caused KD and post-exposure mortality of adult female exposed at a range of 5-28 cm. These results suggest both contact and spatial capacity of the PIRK, with greatest potency to nymphs adults and the prostriate tick the metastriate species and Future studies will explore spatial activity at a range of distances and exposure times, in the presence and absence of host cues and under semi-field conditions.