In 1967 the following chemicals were tested in the U.A.R. and found to be effective against the Egyptian cotton leafworm Spodoptera littoralis (Boisduval). All closages are expressed as kilograms active ingredient per feddan (1.05 acres). Cyolane®(cyclic ethylene (diethoxyphosphinyl) dithioimidocarbonate) at 0.375, endrin at 0.6 + dicrotophos at 0.6 and a mixture of DDT + lindane + methyl parathion at 1.2 + 0.36 + 0.375 proved to maintain their high initial control and residual effect 3 days after application against 2nd-stage larvae. These insecticides were recommended in the U.A.R. by the Ministry of Agriculture for large-scale application during the 1967 cotton-growing season. Among the newly tested insecticides Dursban® (O, O-diethyl O-3,5,6-trichloro-2 pyridyl phosphorothioate) at 0.408, E.I. 47470 (2-(dietnoxyphosphinylimino)-4-methl-1,3-dithiolane at 0.375, Sumithion® 100 (O, O-dimethyl O-4-nitro-m-tolyl phosphorothioate) at 1.25, PH 76-24 (tetradifon + Sumithion) at 0.16 + 1.9, monocrotophos at 0.870, Gardona® (2-chlom-1-(2,4,5-trichlorophenyl)vinyl dimethyl phosphate at 0.750, DDT + endosulfan + methyl parathion at 1.40 + 0.40 and VCS-506 (O-(4-bromo 2,5-dichlorophenyl) O-methyl phenylphosphonothioate) at 0.525 gave also high initial control and reasonably high residual effect after 3 and 6 days against the 2nd- and 4th-stage larvae. 1968 results indicate that over 90% initial control and over 50% control after 3 days of the 4th-stage larvae were obtained following use of: phoxim at 1.0, toxaphene + EPN (O-ethyl O-p-nitrophenyl phenylphosphonothioate) at 1.6 + 0.40, monocrotophos at 0.58, VCS-506 at 0.700, Dursban® at 0.408, Cyolane® at 0.375; E.I. 47470 at 0.375, monocrotophos at 0.60, Sumithion® at 1.75, endrin + dicrotophos at 0.5 + 0.5. endrin + VCS-506 at 0.195 + 0.175, DDT + methyl parathion at 1.0 + 0.375, Gardona at 0.750, Lannate® (S-methyl N-[ (methylcarbamoyl) oxy]thioacetimidate) at 0.90 and 1.80, Dupont 1642 (methyl N-(carbamoyloxy) thioacetimidate) at 0.90 and 1.80, and endrin + methyl parathion at 0.39 + 0.50