Sevin® (1-naphthyl N -methylearbamate) and Zectran® (4-di- methylamino-3,5-xylyl N -methylcarbamate) were evaluated for their effectiveness against insects occurring on the following crops: cauliflower, celery, corn, cotton, peppers, and tomatoes. A 5% Sevin dust provided effective control of the corn earworm (Heliothis zea (Boddie)) on sweet corn; on cotton, Sevin at 2 pounds of toxicant per acre gave evidence of a lasting residual control of cotton leaf perforator ( Bucculatrix thurberiella Busck), salt-marsh caterpillar (Estigmene acrea (Drury)), and cotton bollworm (=corn earworm) larvae. Zectran, applied at from 0.5 to 1 pound per acre, provided excellent control of western flower thrips ( Frankliniella occidentalis is (Pergande), leafminers, ( Liriomyza spp.), and various species of lepidopterous larvae and flea beetles. On cotton, effective residues of Zectran do not seem to persist so long as those of Sevin. Both compounds were destructive to a variety of beneficial insect species on cotton. The addition of piperonyl but oxide did not consistently and markedly increase the toxicity of Sevin to larvae of the cabbage looper ( Trichoplusia ni (Hubner)), beet armyworm ( Spodoptera exigua (Hubner)), cabbage aphid ( Brevicoryne brassicae (L.)), and green peach aphid ( Myzus persicae (Sulzer)) on cauliflower and celery. Five per cent dusts of Bayer 37344 (3,5-dimethyl-4-methylthiophenyl N -methylcarbamate), Bayer 39007 ( o -isopropoxyphenyl N -methyl carbamate), and Union Carbide 10854 ( m -isopropylphenyl N -methyl carbamate) gave fair control of corn earworms on sweet corn. Beet armyworms on celery were not effectively controlled by l.2 pounds per acre of Bayer 37344.