The toxicity of toxaphene and dieldrin, when used against the boll weevil, 

 was not greatly reduced by a Z4-hour exposure of treated plants to simulated 

 wind (4.7 m.p.h.). The toxicity of aldrin was greatly reduced during the 24-hour 

 period, even in the absence of wind. 



1953 - Mistric, W. J., Jr., and J. C. Gaines. The toxicity of certain insecticides to the 

 overwintered boll weevil. J. Econ. Ent. 46(2) :350-352. 



Laboratory and field cage tests were conducted to determine the effective- 

 ness of toxaphene, aldrin, dieldrin, heptachlor and BHC when used to control the 

 overwintered boll weevil. In the laboratory tests all of these insecticides gave 

 effective control of the weevil, with the exception of heptachlor which was used 

 at a low dosage. In the field cage tests dieldrin was the only insecticide tested 

 that gave effective control of the overwintered weevil. The toxicity of toxaphene 

 and aldrin was greatly reduced, while heptachlor and BHC proved ineffective. 



It is generally agreed that overwintered weevils, due to their lowered re- 

 sistance, can be satisfactorily controlled early in the season with relatively low 

 dosages of certain organic insecticides. However, the results of this study indi- 

 cate that when certain climatic conditions are favorable to the boll weevil and 

 unfavorable for the insecticides, higher dosages of the insecticides may be needed 

 to obtain effective control of the overwintered boll weevil. 



1953 - Parencia, C. R., Jr., and C. B. Cowan, Jr. Control of the boll weevil and the boll- 

 worm with organic insecticides in 1952. J. Econ. Ent. 46(6) : 1034- 1038. 



Small-plot and large-scale field experiments comparing insecticides applied 

 as dusts and as low-volume sprays were conducted at Waco, Tex., during 195 2 

 for the control of late -season infestations of the boll weevil and the bollworm, 

 Heliothis armigera (Hbn.). 



In a small-plot experiment, an EPN-DDT spray applied at a rate of 0.5 or 

 0.625 pound of EPN plus 0.75 pound of DDT per acre gave boll weevil control 

 equal to that obtained with a dust containing sufficient BHC to give 3% of the 

 gamma isomer, 5% of DDT, and 40% of sulfur. Sprays applied at the following 

 acre -dosages were equally effective in controlling the boll weevil: toxaphene 

 1.9 pound plus DDT 0.92 pound; aldrin 0.33 pound plus DDT 0.67 pound; endrin 

 0.33 pound; dieldrin 0.27 pound plus DDT 0.67 pound; and heptachlor 0.33 pound 

 plus DDT 0.67 pound. In another small-plot experiment conducted for boll weevil 

 control, lime-free calcium arsenate containing 1% of parathion, and 20% of toxa- 

 phene plus 40% sulfur dusts, and a 0.3-pound dosage of endrin spray produced a 

 significant increase in yield over that produced by a 0.2-pound dosage. In a 

 large-scale experiment, metacide applied in a spray at an average rate of 0.5 

 pound per acre gave slightly better boll weevil control than toxaphene plus DDT 

 spray but failed to control bollworms. Lime-free calcium arsenate containing 1% 

 of parathion showed a longer period of residual toxicity to boll weevils than 20% 

 toxaphene plus 40% sulfur dust. 



1953 - Parencia, C. R., Jr., and K. P. Ewing. Late-season control of boll weevil and 

 bollworm with sprays and dusts in 1950. J. Econ. Ent. 46(1): 108- 1 12. 



In 1950, several organic insecticides applied as low-volume sprays and as 

 dusts were tested in small-plot and large-scale field experiments against late- 

 season infestations of the boll weevil and the bollworm, Heliothis armigera (Hbn.). 

 One large-scale airplane experiment was conducted in northern Texas, near 

 Ladonia, and the other experiments were conducted in central Texas, near Waco. 



The following dust treatments were equally effective in controlling the boll 

 weevil: 20% of toxaphene plus 40% of sulfur; 10% of chlordane, 5% of DDT and 40% 

 of sulfur; 2.5% of aldrin, 5% of DDT, and 40% of sulfur; 5% of DDT, 40% of sulfur, 

 and enough benzene hexachloride to provide 3% gamma isomer in the finished 

 dust; 5% of heptachlor and 5% of DDT; and 2.5% of dieldrin. 



In one small-plot experiment, there was no significant difference in yield 

 between plots dusted with a mixture of DDT, sulfur, and either benzene hexa- 

 chloride or aldrin, and those sprayed with DDT plus benzene hexachloride, aldrin, 

 or heptachlor. In another experiment, plots dusted with toxaphene or dieldrin 



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