B (j 



Sued April, 1820 



EMPOISONING THE13 

 COTTON BOLL WEEVIL 



BY B.R. COAD, SENIOR ENTOMOLOGIST, AND R.C. GAINES, ASSOCIATE 

 ENTOMOLOGIST. DIVISION OF COTTON INSECTS. BUREAU OF ENTOMOLOGY 



LEAFLET M®.57 



UNITED STATED DEPARTMENT OF 

 AGRICULTURE.WASHINGTON.D.C K^3 



Control of the cotton-boll weevil by dusting with calcium arsenate 

 has been practiced by farmers for approximately 10 years. During 

 this period the method has been tested throughout most of the dis- 

 tricts in the Cotton Belt which suffer damage by the weevil, and has 

 thus encountered a wide diversity of conditions as well as of seasonal 

 variations, especially in infestation and climate. Dusting with cal- 

 cium arsenate began as an entirely new operation and has undergone 

 a steady process of development in methods, equipment, and technic. 

 This process is still under way, but the method to-day shows great 

 improvement and adaptation to a wider diversity of condition- than 

 at first seemed possible. However, the same fundamental principles 

 still apply, and continued experience merely emphasizes the fact that 

 successful control can be expected only with an understanding of these 

 principles. 



Do It Right or Not at All 



As control of boll weevils with poison dust first began to be prac- 

 ticed in new localities and new problems in control were encoun- 

 tered, many opinions naturally arose as to the best plan of operation. 

 For a time considerable confusion resulted. To correct this condition 

 the cotton council of the southern agricultural workers, composed of 

 representative scientific men from all sections of the Cotton Belt, 

 made a long series of studies of control of the boll weevil. Experi- 

 ments were conducted in many sections, and after careful analysis 

 of the results the cotton council adopted one general recommendation 

 which had. when followed, given the most universally successful con- 

 trol under a wide variety of conditions. This recommendation is the 

 basis of practically all present-day control of the boll weevil by 

 poisoning but is, of course, subject to variations to meet particular 

 local conditions. As stated by the cotton council, it is as follow- : 



For the boll weevil, one presquare poisoning may be applied if it appears that. 

 there are numerous overwintered weevils present This should be given jusi as 

 squares begin to form. Then apply the regular series of three or more dust 



applications of calcium arsenate at four or five day intervals, beginning . 

 an average of approximately one-tenth of the squares show weevil punctures. 

 Dusting should he continued as needed to keep this infestation low until a full 

 crop is set and matured beyond the probability of further weevil injury. 

 07°— 29 



