In another small-plot experiment at Waco, there was some indication that a 

 special calcium arsenate was more compatible with benzene hexachloride, espe- 

 cially at 1% of the gamma isomer than was the regular calcium arsenate. 



When parathion mixed with chlorinated camphene was dusted on cotton, the 

 2 insecticides appeared to be compatible, but indications were that 2% of parathion 

 was not effective against the boll weevil. 



1948 - Gaines, J. C., and H. A. Dean. Tests of insecticides for the control of several 

 cotton insects. J. Econ. Ent. 41(4):548-554. 



Twenty percent chlorinated camphene -sulphur and 3% gamma benzene hexa- 

 chloride -5% DDT -sulphur gave significantly better control of the bollworm and 

 higher yields than calcium arsenate. All 3 poisons were equally effective against 

 the boll weevil. Of the 3, only calcium arsenate produced increased populations of 

 aphids. 



In a demonstration using 5-acre plots, the 3% gamma benzene hexachloride- 

 5% DDT -sulphur gave better control of the bollworm than did calcium arsenate 

 but no better control of the weevil. This mixture gave better control of the boll 

 weevil than 20% chlorinated camphene -sulphur. The highest yield was produced 

 on the plot treated with benzene hexachloride -DDT -sulphur mixture. 



The 20% chlorinated camphene -sulphur and 3% gamma benzene hexachloride- 

 5% DDT -sulphur were more effective against the bollworm than calcium arsenate. 

 Calcium arsenate was as effective as these organic sulphur mixtures when used 

 against the boll weevil. 



In 2 experiments, these 2 organic sulphur mixtures produced more cotton 

 than did calcium arsenate, while in another the calcium arsenate produced as 

 much as the organics. Aphid increases did not result from the use of organic - 

 sulphur mixtures. 



1948 - Gaines, R. C., and A. L,. Scales. Effectiveness of insecticides on the boll weevil 

 in cotton squares in 1947. J. Econ. Ent. 41(3):519. 



To test the fumigating action of insecticides, squares collected on August 18, 

 were exposed for 21 days in airtight lantern globes to the vapors of only chlordan, 

 benzene hexachloride, chlorinated camphene, or parathion (0,0-diethyl 0-p-nitro- 

 phenyl triphosphate). Squares collected on August 20 were taken to the labora- 

 tory and placed in a dusting chamber where they were given a fairly heavy appli- 

 cation. After treatment the squares were placed in lantern globes for 19 days. > 

 This was a combination contact and vapor, or fumigation, test. 



The vapors from the chlordan killed all the developing boll weevils and those 

 from the benzene hexachloride and the parathion killed most of them. The chlori- 

 nated camphene did not give off vapors which affected, to any extent, the develop- 

 ment of the immature stages. In the tests in the dusting chamber the chlordan and 

 benzene hexachloride killed all the developing boll weevils, whereas parathion 

 and chlorinated camphene were less effective. 



In the fumigation test, the boll weevils treated with chlordan reached the 

 adult stage and died within the squares. In the combination contact and fumigation 

 test, both larvae and adults were found dead. The benzene hexachloride killed a 

 larger proportion of larvae than of adults. 



Beginning on August 18, 4 heavy applications of 4 insecticides were made on 

 plots consisting of 4 rows 100 feet long. At the strengths used, chlorinated cam- 

 phene and parathion had no effect whatever upon the developing boll weevils in 

 cotton squares; whereas chlordan caused high mortality, and benzene hexachlo- 

 ride cause some mortality of the developing weevils. 



1948 - Gaines, J. C., and Read Wipprecht. Effect of dusting schedules on the yield of 

 cotton during 1947. J. Econ. Ent. 41(3) :410-41 2. 



Two experiments were conducted to compare 3 schedules: (1) early dusting 

 to control thrips, followed by complete fleahopper, boll weevil, and bollworm 

 control; (2) dusting for standard cotton fleahopper, weevil, and bollworm control; 

 and (3) late dusting for weevil and bollworm control. Early-season applications of 

 5% DDT-sulphur or 3% gamma BHC-5% DDT -sulphur failed to prevent thrip 



44 



