Two spray formulations of Am. Cyanamid 3911 were applied three times to 

 the foliage at an average rate of a little over 2 pounds of the technical material 

 per acre. Both formulations gave some control of the boll weevil and prevented 

 an aphid buildup but did not increase the yield. 



1956 - Rainwater, C. F. Bayer 17147, a promising new insecticide for cotton insects. 

 Agr. Chemicals ll(2):32-33. 



Results of tests at Brownsville, College Station, and Waco, Tex.; Tallulah, 

 La.; Stoneville, Miss.; and Florence, S.C. 



1956 - Richmond, Clyde A. Tests with phosphorus insecticides for control of pink boll- 

 worm and some other cotton pests, 1955. J. Econ. Ent. 49(6):874. 



The following sprays were tested: Bayer 17147, Bayer 17147-DDT, dieldrin- 

 DDT, and endrin. All the insecticides gave good control of the boll weevil and 

 were equally effective. 



1956 - Siddiqi, A. A. Studies on the residual toxicity of certain organic insecticides for 

 the control of the boll weevil (Anthonomus grandis Boh.). Indian J. Ent. 18(1):45- 

 48. 



In tests in Louisiana, laboratory-reared adults of Anthonomus grandis were 

 caged on cotton plants immediately after, or 24 or 48 hours after the plants had 

 been sprayed. They were examined for mortality 48 hours after being caged. The 

 results showed that applications of 0.2 lb. of endrin, 2.0 lbs. of toxaphene, and 

 mixtures of 0.5 lb. of DDT with 0.15 lb. of dieldrin or 0.3 lb. of gamma BHC per 

 acre, all significantly reduced insect populations. There was no significant dif- 

 ference between the first 3 in immediate or residual effect, though endrin seemed 

 to be the most toxic. The first 3 were significantly better than the BHC mixture. 



1956 - Walker, J. K., Jr., B. G. Hightower, R. L. Hanna, and D. F. Martin. Control of 

 boll weevils resistant to chlorinated hydrocarbons. Tex. Agr. Expt. Sta. Prog. 

 Rpt. 1902. Nov. 7. 



Chlorinated hydrocarbon insecticides failed to give commercial control in 

 several fields in the Brazos River Valley in 1956. Calcium arsenate and several 

 phosphorus compounds were effective. 



1956 - Walker, R. L., and A. R. Hopkins. Studies on the control of boll weevils in 



surface woods trash. J. Econ. Ent. 49(5):696. 



A large-scale field experiment and a cage experiment were conducted in South 

 Carolina in 1954 and 1955 to determine the effectiveness of granulated insecticides 

 applied to surface woods trash to control overwintering boll weevils. In the large- 

 scale experiment, aerial applications made to surface woods trash in a small 

 agricultural community reduced boll weevil populations considerably. The cage 

 experiment demonstrated that a high kill of overwintering weevils could be ob- 

 tained in this manner. 



1957 - Blum, Murray S., Norman W. Earle, and John S. Roussel. The metabolism of 



DDT in the boll weevil (Anthonomus grandis). Ent. Soc. Amer. B. 3(3):226. 

 Sept. 1957. 



Rates of penetration of DDT in weevils of different ages and strains. Pene- 

 tration is slowest in overwintering weevils and fastest in weevils 1-2 days old. 

 No differences are observed in the penetration rates in chlorinated hydrocarbon 

 resistant and susceptible weevils. A large percentage of the penetrated DDT is 

 converted to a metabolite which does not respond to the Schechter-Haller test. 

 DDE is produced in trace amounts, but neither DDE or DDA are metabolized 

 appreciably by the weevil. DDT synergists, when applied either topically or by 

 injection with DDT, show negligible activity. However, DDT is substantially more 

 toxic to the weevil when injected, as compared with topical application. The topi- 

 cal LD50 of DDT varies with the age of the weevil and with the strain examined. 

 The ineffectiveness of DDT as a weevil insecticide is discussed in relation to 

 these results. 



70 



