.LETTER OF TRANSMITTAL. 



U. S. Department of Agriculture, 



Division of Entomology, 

 Washington, D. C, Januari/ 18, 1904- 

 Sir: I have the honor to transmit herewith the manuscript of an account of the 

 cotton l)ollworni, Imsed on investigations conducted during the year 1903, according 

 to special Congressional appropriation made for the purpose, and ])repared by Mr. 

 A. L. Quaintance, agent in charge of cotton bollworir investigations. The bollworm 

 is one of the most destructive insects of the ITnited f-Jtates, and, as the information 

 furnished in this article is confidently believed to be of much value to cotton growers, 

 it is urged that it be given immediate publication. 



Respectfully, L. O. Howard, 



EmlomologisL 

 Hon. James Wilson, 



Secretary of Agriculture. 



CONTENTS. 



Pasre 



Introductory 3 



Injury in 1903 4 



Distribution — 5 



General appearance and life cycle 6 



Food plants 7 



Number of generations 8 



The bollworm on corn 9 



The bollworm on cotton 10 



Some factors which tend to keep boll worms reduced 14 



Ineffective methods of bollworm control \ 15 



Lights for trapping moths 15 



Poisoned sweets 15 



Burning sulphur in cotton fields 16 



Resistant varieties ^ 16 



Field experiments in 1903 16 



Cultural methods 16 



Arsenical poisons 19 



Corn as a trap crop 21 



Specific recommendations 22 



ILLUSTRATIONS. 



Page. 



Fig. 1. Map of Texas, showing territory ravaged by bollworm in 1903 5 



2. The bollworm moth, about twice natural size 7 



3. Young corn plant, showing injury to the "bud" by the bollworm 10 



4. Roasting ear infested by bollworm 11 



5. Normal, and ' ' flared ' ' cotton square due to bollworm injury 12 



6. Cotton -boll and bollworm, showing mode of attack 13 



7. Opened boll, to show bollworm at work within 14 



191 



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