In field and cage tests benzene hexachloride gave a much quicker kill of the 

 boll weevil than did calcium arsenate, but it lost most of its toxicity within about 

 2 days. On the other hand, against cotton leafworms its effect was much more 

 residual than was that of calcium arsenate. There was evidence that benzene 

 hexachloride may be incompatible with standard calcium arsenate. 



1947 - Gaines, J. C. Comparison of insecticides for cotton insect control and the effect 

 of copper on yields. J. Econ. Ent. 40(3):434-436. 



Lead arsenate proved to be almost as effective as calcium arsenate when 

 used against heavy infestations of weevils and was more effective against the 

 bollworm. The benzene hexachloride -inert mixture containing 5.75% gamma 

 isomer was effective against the weevil and prevented aphid increases, but per- 

 mitted increased bollworm injury. 



1947 - Gaines, J. C., and H. A. Dean. New insecticides for boll weevil, bollworm, and 

 aphid control. J. Econ. Ent. 40(3):365-370. 



Benzene hexachloride mixtures applied at the rate of 1 1 to 12 lbs. per acre, 

 containing as low as 2.88% gamma isomer proved to be as effective against the 

 weevil as calcium arsenate in one experiment, while in other experiments this 

 percentage gamma isomer was less effective. The mixtures applied at from 11 

 to 12 lbs. per acre, containing at least 5% gamma isomer were equal to or, in one 

 experiment, significantly more effective against weevils than calcium arsenate. 

 Apparently a minimum dosage of 8 ounces of gamma isomer per acre was nec- 

 essary to give adequate control of severe weevil infestations. Benzene hexa- 

 chloride, in all concentrations used, prevented aphid increases, but produced 

 increased bollworm injury. Five percent DDT dust mixtures were effective against 

 the bollworm, but ineffective against bollils and caused aphid increases. Popula- 

 tions of red spiders were noted on both DDT and benzene hexachloride treated 

 plots when sulphur was not used as a diluent. The mixture of DDT and benzene 

 hexachloride was effective against weevils, bollworms and aphids, but did not 

 significantly increase the yields over calcium arsenate. 



1947 - Gaines, R. C., A. L. Scales, M. T. Young, and G. L. Garrison. Effect of benzene 

 hexachloride mixtures upon four cotton insects and upon cotton yields at Tallulah, 

 Louisiana, in 1946. Assoc. South. Agr. Workers Proc. 44:125. 



Results obtained in laboratory tests, cage experiments, and field plot experi- 

 ments indicated that benzene hexachloride was toxic to the boll weevil. One -half 

 pound of gamma isomer in benzene hexachloride mixtures may be required. 



1947 - Gaines, R. C., M. T. Young, and G. L. Smith. Calcium arsenate and nicotine to 

 control boll weevil and cotton aphid, 1939-1946. J. Econ. Ent. 40(4):600-603. 



In experiments at Tallulah, La., 2% of nicotine in alternate applications of 

 calcium arsenate, 1% of nicotine in all applications of calcium arsenate, and 

 calcium arsenate plus separate applications of a 3% nicotine dust as needed were 

 equally effective for control of the boll weevil, and the cotton aphid, Aphis gos- 

 sypii Glov. 



Early-morning and late -afternoon applications of nicotine -calcium arsenate 

 mixtures, each, gave a significant increase in yield over calcium arsenate and 

 over the checks. The late applications were slightly more effective. 



1947 - Ivy, E. E., and K. P. Ewing. Laboratory and cage tests with newer insecticides 

 to control cotton insects. J. Econ. Ent. 40(4):568-569. 



Laboratory and cage tests designed to determine the effectiveness of several 

 of the newer insecticides against cotton insects were conducted at Waco, Tex., 

 during 1946. 



Dust mixtures of chlordane were made by impregnating a dust with an ace- 

 tone solution. Pyrophyllite was used in the 1% to 5% mixtures, and "fossil flour" 

 (infusorial earth), in the 10% to 20% mixtures. At 10% and 20% concentrations 

 chlordane was effective against cotton aphids and boll weevils, but not quite so 

 effective as corresponding concentrations of chlorinated camphene or benzene 

 hexachloride (gamma isomer 5.75%), 



41 



