In laboratory tests at Brownsville, Tex., Sevin (1-naphthyl-N-methyl carbamate) applied as a spray to potted cotton plants was effective against the boll weevil (Anthonomus grandis Boh.), the pink boll worm (Pectinophora gossypiella (Saund.)) the boll worm (Heliothis zea (Boddie)), the cabbage looper (Trichoplusia ni (Hbn.)), and the cotton aphid (Aphis gossypii Glov.). On field plots in the Lower Rio Grande Valley, dusts containing 1.5 to 2.5 pounds of Sevin per acre applied at 4- to 7-day intervals gave control of the pink boll worm and boll weevil comparable with that obtained with standard insecticides.