In field tests 10 repellents were used as 25% solns. on the skin; 6 were effective for 113 min. or more against Aedes flavescens, and 7 for 34 min. or more against A. excrucians, A. communis, and A. pionips. Propyl N,N-diethylsuccinamate was the most effective against A. flavescens, whereas this material and dimethyl phthalate, which were about equally effective, afforded better protection than the other materials against the mixed population of Aedes. Cream prepns. containing 20% of the 10 repellents were slightly less effective than 25% concns. of the repellents applied as liquids. In tests with 35 materials applied to fabrics, 10 were effective against mosquitoes after 4 rinsings and 16 hours of wear. Hexylmandelate, which was the most effective, withstood 13 rinsings and 40 hrs. of wear. Repellents applied to mesh face masks failed to give adequate protection from sand flies (Culicoides).