Repellent Tests Against Leptotrombidium (Leptotrombidium) Fletcheri (Acari: Trombiculidae)

An evaluation of standard and experimental repellents was made against the chigger mite Leptotrombidium (Leptotrombidium) fletcheri using dose-response methods. Deet and dimethyl phthalate were significantly more effective ( P < 0.05) than Citronyl, Indalone, MGK repellent 326, ethyl hexanediol, dibutyl phthalate, and Stabilene (ranked by ED50). None of the 11 experimental compounds tested were significantly better than deet, and all compounds except RH-398 were significantly better than permethrin. These data indicate that permethrin may not provide adequate protection against certain vectors of scrub typhus.