Efficacy of chemical repellents against Otobius megnini (Acari: Argasidae) and three species of ixodid ticks.

Otobius megnini (Dugès), often referred to as the ear tick or spinose ear tick, is a one-host tick native to the southwestern United States and Mexico. Infestations of this species can cause severe irritation and may affect breeding behavior in the host. Although chemical repellents are commonly used as an alternative approach to conventional arthropod vector control, information on repellency against O. megnini is lacking. This study compared repellency of ammonia, BioUD(®), 98.25% DEET, garlic pepper tea, permanone, and pyrethrin with piperonyl butoxide, against larvae stages of O. megnini, Amblyomma americanum (L.), Dermacentor variabilis (Say), and Rhipicephalus sanguineus (Latreille). To test for repellency, tick movement was recorded at 30 s intervals for five min after introduction to a partially treated piece of filter paper. Results showed larvae of O. megnini exhibited less aversion to the chemicals tested when compared to the other tick species.