BULLETIN OF THE 



No. 107 



Contribution from the Bureau of Biological Survey, Henry W. Henshaw. Chief. 

 July 27, 1914. 



(PROFESSIONAL PAPER.) 



BIRDS IN RELATION TO THE ALFALFA WEEVIL. 



By E. R. KALMBACH, Assistant Biologist. 

 INTRODUCTION. 



The alfalfa weevil (Phytonomus posticus Gyll.), a pest introduced 

 into the United States, has for several years been doing enormous 

 damage to alfalfa crops in Utah. On invitation of and in coopera- 

 tion with the Bureau of Entomology, the Biological Survey there- 

 fore undertook to ascertain 

 the part played by birds 

 and mammals in checking 

 the increase of the weevil. 

 Accordingly the writer 

 spent from May 8 to July 

 25, 1911, and from April 1 

 to August 15, 1912, at vari- 

 ous points in the infested 

 region, investigating the 

 food habits of local birds 

 and of a few batrachians 

 and other vertebrates. 

 This bulletin chiefly con- 

 siders the food habits of birds, but facts concerning the economic 

 status of other vertebrates also are included. 



IMPORTATION AND SPREAD OF THE ALFALFA WEEVIL IN UTAH. 



The time and method of initial introduction of the alfalfa weevil 

 into Utah is unknown, but the first serious damage was noted in the 

 spring of- 1904, when a small infestation a few miles southeast of 

 Salt Lake City was discovered. From this foothold the weevil spread 

 and by September, 1911, had extended as far north as Tremonton, 



NOTE. This bulletin discusses the food habits and economic status of birds, and of 

 the toad, frog, and a few other vertebrate enemies of the alfalfa weevil in Utah. 

 43778 Bull. 10714 - 1 



FIG. 1. Known distribution of the alfalfa weevil 

 (Phytonomus posticus), May 1, 1914. (Map by 

 Bureau of Entomology.) 



