slightly higher yields. Boll weevil control was also obtained with a dust contain- 

 ing 3% of the gamma isomer of benzene hexachloride plus 5% of DDT plus 0.5% 

 of parathion followed closely by 20% of toxaphene plus 0.5% of parathion and by a 

 dust containing 2% of the gamma isomer plus 10% of DDT plus 40% of sulfur plus 

 2.3% of an unknown solvent. 



These treatments also gave the highest yields. A moderate to light infesta- 

 tion of the red spider, Tetranychus atlanticus McG., developed after all treat- 

 ments with the exception of the one containing 40 percent of sulfur. Higher yields 

 and better boll weevil control were obtained at 3- and 5 -day intervals of applica- 

 tion than at the 7 -day interval. 



1949 - Gaines, J. C., and H. A. Dean. Effect of temperature and humidity on the toxicity 

 of certain insecticides. J. Econ. Ent. 42(3) :429-433. 



In cage tests with boll weevils, the toxicity of calcium arsenate remained 

 more nearly the same under all temperatures than did that of any of the organic 

 insecticides used. However, the toxicity of this material was reduced, both by 

 high temperature and high humidity. Laboratory-reared weevils were consid- 

 erably more susceptible to the organic insecticides than were field-collected 

 weevils. 



High temperature and high humidity had less effect on the toxicity of 20 per- 

 cent toxaphene than on that of the other organics. However, the toxicity of this 

 material was reduced appreciably by high temperatures. The toxicity of 3 per- 

 cent gamma benzene hexachloride -5 percent DDT was also reduced by high 

 temperatures, necessitating dosages as great as 30 pounds per acre in order 

 to obtain a high mortality. 



The toxicity of 10 percent chlordane was greatly reduced by high tempera- 

 tures. At the higher temperatures it was necessary to use 23 pounds of this 

 material per acre in order to effect even a 50 percent mortality. In tests in 

 which the weevils were released 24 hours after the plants were dusted, the 

 toxicity of chlordane was further reduced. 



In tests conducted at a constant temperature, high humidity reduced the 

 toxicity of calcium arsenate, 20 percent toxaphene, and 20 percent chlordane. 



A delay in releasing weevils 24 hours after dusting the plants, and the 

 exposure of the dusted plants to the sun for 4 hours, resulted in reduced toxicity 

 of 20 percent toxaphene. 



1949 - Gaines, J. C., and H. A. Dean. Insecticide tests for boll weevil control during 

 1948. J. Econ. Ent. 42(5):795-798. 



"Special calcium arsenate (lime free) mixed with either parathion or ben- 

 zene hexachloride, and 20 percent toxaphene -sulfur were equally effective against 

 the boll weevil. These materials were more effective than either benzene hexa- 

 chloride -DDT -sulfur or chlordane -DDT -sulfur under the conditions of a hot 

 season and heavy migration." 



1949 - Moreno, Ignacio. Cotton insect control with new organic insecticides in Mexico. 

 J. Econ. Ent. 42(3):484-486. 



The work reported in this paper and carried on as a demonstration of the 

 effectiveness of new organic insecticides for the control of various cotton insect 

 pests in late-planted cotton in the Laguna District of Mexico suggests the fol- 

 lowing points: 



(a) Cotton insect pests can be effectively controlled bythe proper use of ade- 

 quate insecticides. 



(b) Where no cotton could formerly be picked due to insect damage, yields 

 can be considerably improved through the use of insecticides. 



(c) Frequent applications of insecticides at intervals of about 7 days are of 

 the utmost importance. 



(d) Benzene hexachloride, up to 6 percent gamma isomer, did not prevent a 

 buildup of pink bollworm infestation, for which DDT is necessary. A 2 

 percent gamma isomer concentration of benzene hexachloride controlled 



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