UNITED STATES DEPARTMENT OF AGRICULTURE 



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1 BULLETIN No. 231 i 



Contribution from the Bureau of Entomology 

 L. O. HOWARD, Chief 



SU^'^mTU 



Washington, D. C. 



PROFESSIONAL PAPER 



August 2, 1915. 



RECENT STUDIES OF THE MEXICAN COTTON 

 BOLL WEEVIL. 



By B. R. Coad, Entomological Assistant, Southern Field Crop Insect Investigations. 



CONTENTS. 



Page. 



Introduction 1 



Distribution 2 



Food plants 3 



Characteristics of the adult -1 



Longevity of adult weevils a 



Sex of adul ts 10 



Reproduction 10 



Development 



Hibernation 



Natural control 



Behavior of Louisiana weevils at Victoria... 



Development of Thurbcria thespcsioidcs 



Examination of Thurberia bolls 



1'age. 

 27 

 31 

 31 

 32 

 33 

 33 



INTRODUCTION. 



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

 of the boll weevil, Anthon- 

 omus grandis Boh., because 

 of severaloppor tune discov- 

 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- 

 plorations of southeastern 

 Arizona by Dr . A. W . Morrill 

 and Mr. W. D. Pierce in 

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



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

 shading shows the infested area; the heavy lines, the limits 

 of cotton production; the broken line, the probable distribu- 

 tion of the Arizona wild cotton weevil. (Original.) 



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

 89032°— Bull. 231—15 1 



