Circular No. 137. 



Issued April 20, 1911. 



United States Department of Agriculture, 



BUREAU OF ENTOMOLOGY. 

 L. O. HOWARD, Entomologist and Chief of Bureau. 



THE ALFALFA WEEVIL. 



{PIn/toiioiiiiifi »iuriiius Fab.) 



By F. M. Webster. 



In Charge of Cereal and Forage Insect Invexligaiions. 



IXTRODUCTIOX. 



The alfalfa weevil {Phi/tonomus murinus Fab.) is not native to 

 America, but has been accidentally introduced from Europe, western 

 Asia, or northern Africa, where it is common, and where, while more 

 or less destructive to alfalfa, 

 it is probably prevented by 

 its natural enemies from 

 working serious and wide- 

 spread ravages. Just where 

 or in what manner it was 

 brought to this country no 

 one knows, but it was first 

 discovered in the spring of 

 1904 in a small field of al- 

 falfa near Salt Lake City, 

 Utah, and attention 

 promptly called to its pres- 

 ence there by the entomolo- 

 gist of the Utah Agricul- 

 tural Experiment Station.** 



THE rULLY DEVELOPED 

 INSECT. 



The beetle itself (fig. 1) Fig. l.— The alfalfa weevil (Phytonomus mtiri- 

 n i„ ii ,. „ nits) : Adults clusterins? on and attacking sprig 



IS usually less than one- ^, ^^,^^,^ ^„„„, „,,„;.^„ ^,.^^^ rorigin:i.) 

 fourth of an inch in length, 



varying from one-eighth to three-sixteenths inch, and when freshly 

 emerged from the cocoon (fig. .'), much enlarged), within which 

 it passes from the larva (fig. G, much enlarged) to the pupa (fig. 



oUtah Agricultural College Experiment Station, Rulletin 110. The Alfalfa 

 I.eaf-weevil. by E. G. Titus, Logan, Utah, September, I'JlO. 



