Excellent control of boll weevils was obtained with all materials tested. The 

 seasonal average of boll weevil-punctured squares was about 36% in the treated 

 plots, as compared with 90% in the untreated check. Increases in yields ranging 

 from 808 to 1,191 pounds of seed cotton per acre were obtained from alltreatments. 



1950 - Fife, L. C., R. L. Walker, Jr., and C. E. Jernigan. Several promising new pesti- 

 cides tested. S.C. Agr. Expt. Sta. Rpt. 63:98-99. Dec. Clemson. 



Compound 1189 and Dilan, where applied as a dust at the rate of 2 pounds of 

 technical grade per acre, were less effective against the boll weevil than the rec- 

 ommended insecticides. 



1950 - Fife, L. C., R. L,. Walker, Jr., and C. E. Jernigan. Profit realized from boll 

 weevil control. S.C. Agr. Expt. Sta. Rpt. 63:98. Dec. Clemson. 



Tests were conducted in 6 fields with a total area of about 30 acres. Half of 

 each field was dusted and half was sprayed. Two untreated outside plots of 1/2- 

 acre, each, served as checks. 



There was a net profit of about $116 to $119 per acre, and, for each dollar 

 spent for poisoning, there was a return of about $5. 



In one field, which produced 1-1/4 bales per acre, the net profit was about 

 $175 to $182 per acre for the dusted and sprayed plots, respectively, and for each 

 dollar spent for poisoning there was a return of about $8. 



1950 - Gaines, J. C., and H. A. Dean. Effect of climatic factors on the toxicity of certain 

 insecticides. J. Econ. Ent. 43(5):602-605. 



The results of cage toxicity tests with boll weevils under the conditions of 

 average daily temperatures ranging from 76° to 91°F. are shown. The toxicity 

 of benzene hexachloride-DDT spray was greater than either benzene hexachlo- 

 ride-DDT dust, toxaphene spray or dust, or toxaphene-DDT spray at the 50 per- 

 cent mortality level. The toxaphene spray was equally as toxic as the benzene 

 hexachloride-DDT at the high levels of mortality. 



The results of similar tests with boll weevils under the conditions of aver- 

 age daily temperatures ranging from 75° to 103°F. are shown. The toxicity of all 

 materials was increased by the higher temperatures. There was little difference 

 in the toxicity of toxaphene-DDT spray and toxaphene spray or dust at all levels 

 of mortality. The benzene hexachloride-DDT spray was slightly more effective 

 than the benzene hexachloride-DDT dust. 



Exposing the treated plants to sunshine and simulated dews reduced the 

 toxicity of all insecticides used. In general, the toxaphene and toxaphene-DDT 

 sprays remained more toxic when exposed to simulated dews and sunshine than 

 toxaphene dust or benzene hexachloride spray or dust. 



1950 - Gaines, J. C., and Read Wipprecht. Evaluation of dusting and spraying schedules 

 for cotton insect control. J. Econ. Ent. 43(3):286-288. 



Under the conditions of these experiments, it is apparently more economical 

 to apply insecticides for the control of injurious populations of insects (as needed) 

 than to apply applications early in the seasonplus the necessary later applications 

 to protect the crop from weevils and bollworms. 



1950 - Hanna, R. L,., and J. C. Gaines. Tests of insecticides for control of cotton in- 

 sects during 1949. J. Econ. Ent. 43(3) -.288-289. 



Three experiments indicated that the calcium arsenate mixtures used were 

 slightly more effective against the boll weevil than were the organic insecticides 

 used, while the organic insecticides were slightly more effective than the calcium 

 arsenate mixtures against the bollworm. When yields were used as the criterion, 

 all the materials were equally effective in controlling infestations of both boll 

 weevil and bollworm. 



Aldrin was not so effective against the bollworm and boll weevil as toxa- 

 phene -sulfur and calcium arsenate -parathion. 



The organic insecticide mixtures produced higher yields than the special 

 calcium arsenate mixture due to better bollworm control. 



The addition of parathion or benzene hexachloride to the special calcium 

 arsenate was effective in preventing aphid increases. 



51 



