RESPONSE OF A CHIGGER, EUTROMBICULA-HIRSTI (ACARI, TROMBICULIDAE) TO REPELLENT AND TOXICANT COMPOUNDS IN THE LABORATORY

Laboratory tests were conducted to compare the response of Eutrombicul a hirsti (Sambon) larvae to the compounds dibutylphthalate (DBP), dime thylphthalate (DMP), diethyl methylbenzamide (Deet), benzyl benzoate ( BB), and permethrin. The ED50 for E. hirsti of these compounds when ap plied to filter paper were 0.17 mg/cm2 for DMP, 0.24 mg/cm2 for permet hrin, 0.26 mg/cm2 for Deet, 1.42 mg/cm2 for BB, and >7.21 mg/cm2 for D BP. When impregnated in cloth, DMP, Deet, and BB were highly toxic to larvae at low concentrations, whereas permethrin and DBP were not as r apidly toxic, but were effective.