UNITED STATES DEPARTMENT OF AGRICULTURE 



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1 BULLETIN No. 231 



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Contribution from the Bureau of Entomology 

 L. O. HOWARD, Chief 



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Washington, D. C. 



PROFESSIONAL PAPER 



August 2, 1915. 



RECENT STUDIES OF THE MEXICAN COTTON 

 BOLL WEEVIL. 



By 13. It. Coad, Entomological Assistant, Southern Field Crop Insect Investigations. 



CONTENTS. 



Introduction 



Distribution 



Food plants 



Characteristics of the adult. 

 Longevity of adult weevils. 



Sex of adults 



Reproduction 



Page. 

 1 



2 

 3 

 4 



Development 



Hibernation 



Natural control 



Behavior of Louisiana weevils at Victoria — 



Development of Tliurbcria thespesioides 



Examination of Thurberia bolls 



INTRODUCTION. 



The cotton season of 1913 was of great importance in the study 

 of the boll weevil, Anthon- 

 omus grandis Boh., because 

 ofseveralopportunediscov- 

 eries. Briefly, the events 

 of the year were the dis- 

 covery, by Mr. O. F. Cook, 

 of the cotton boll weevil 

 breeding upon a wild- 

 cotton plant, Thurberia 

 thespesioides, in Arizona; 

 the establishment of breed- 

 ing work at Victoria, Tex., 

 for the purpose of study- 

 ing any changes in the life 

 history of the weevil; the 

 -discovery by the writer of 

 important food adapta- 

 tions of the weevil; ex- 



1 ,• /. ,, , Fig. 1.— Distribution of the Mexican cotton boll weevil. The 



piorations 01 SOUtneaStem shading shows the infested area; the heavy lines, the limits 

 Arizona by Dr. A. W. Morrill of cotton production; the broken line, the probable distribu- 



and Mr W D Pierce in tion of the Arizona wild cotton weevil. (Original.) 

 August, by Mr. Vernon Bailey later in the fall, and by Messrs. 



Note.— This bulletin is of interest to entomologists in the cotton belt. 

 89032°— Bull. 231—15 1 



