Comparative efficacy of diethyltoluamide skinapplication repellent and M-1960 clothing impregnant against mosquitoes

In a set of tests previously discussed in the present series of papers, it was shown that the skin-application repellent diethyltoluamide (deet) was extremely effective against the swarms of mosquitoes in the nipah palm-mangrove swamps of Malaya, but that the protection was limited solely to those parts of the body actually treated with repellent (1, 2). That is, the volunteers sustained mosquito-bites through their untreated clothing or on portions of the exposed skin which had not been covered with repellent. It was, there-fore, decided to perform another series of tests to compare the degree of protection offer-ed by a repellent impregnated into the clothing, with that obtained by using deet. The standard U. S. Army clothing impregnant, M-19602, was chosen for this experiment, and the results, presented in this article, indicate that where mosquitoes are as abundant as they are in the nipah palm-mangrove swamps, it is insufficient to rely solely upon the use of either deet repellent or the wearing of M-1960-treated clothing. Simultaneous use of both methods, however, offered virtually solid protection, even when the untreated controls were being attacked by mosquitoes at the rate of 173-244 per man per hour. MATERIALS AND METHOD