Larvicidal activities of N, N'-dialkylalkylenediamines and other fatty diamines in oil films and water dispersions.

Abstract

Symmetrically disubstituted fatty diamines were synthesized by the reaction of alkyl bromides, H3C-(CH2)7-11-Br, with alkylenediamines, H2N-(CH2)2-6-NH2 or 1,3-diamino-2-propanol. Various formulations of these compounds and commercial compounds were tested against 4th-stage larvae of mosquitoes. In each series of homologues tested activity generally reached a peak with the N, N' -didecyl homologue and diminished as the alkyl chains were lengthened or shortened. The 48-hr LD50 values for Anopheles albimanus Weidemann, Culex pipiens quinquefasciatus Say, and Aedes aegypti (L.) were 0.1, 0.14, and 0.31 ppm when 1.9, 2.5, and 5.6 µl, respectively, of Richfield Larvicide oil containing 5.5% N.N' -didecylputrescine and 4% oleic acid were applied to the 0.5ft2 surface of 1 liter of water containing larvae, The oil plus oleic acid control gave LD50 values of 34, 26, and 34 µl, respectively. The dialkyldiamines showed high activity when dispersed in water by a procedure involving heating and shaking to provide, on cooling, floating needles or fibers of minute size. Against A. albimanus and C. p. quinquejasciatus, best results were obtained with a dispersion of N, N' -didecylputreseine which gave 48-hr LC50 values of 0.041 and 0.014 ppm, respectively, 22 and 35 times that given by Abate® O, O' -(thiodi- p -phenylene) O, O, O', O' -tetramethyl phosphorothioate dispersed in water. Against A. aegypti N, N' -dinonylpropylenediamine was most effective and gave an LC50 of 0.05 ppm, 28 times that given by Abate.