Field evaluation of deet and a piperidine repellent (AI3-37220) against Amblyomma americanum (Acari: Ixodidae).

Repellent efficacy of deet (N,N-diethyl-3-methylbenzamide) and a piperidine, AI3-37220, was evaluated topically on human volunteers against lone star tick, Amblyomma americanum (L.), nymphs and adults in the field. AI3-37220, at 0.5 mg/cm2, provided > 90% repellency against adult and nymphal ticks over a 6-h test period and showed significantly better repellent efficacy than deet. Deet, at the same concentration, provided 85% repellency at 0 h and deteriorated to 55% repellency at 6 h.