124 JOURNAL OF ECONOMIC ENTOMOLOGY [Vol. 10 



Alfalfa, the staple leguminous forage crop of the western half of 

 the United States, is the oldest forage crop known to man. Its origin 

 was probably in the birthplace of the human race and before the dawn 

 of history it was grown by the Persians, who later carried it to Greece. 

 It was brought to Spain by the Moors and to the New World by the 

 Spaniards. It was introduced into our own Pacific Coast from Chili, 

 and its culture has spread until the annual yield of each of the western 

 states is reckoned in millions of dollars. 



Alfalfa is grown where other crops cannot endure the rigors of climate, 

 and under favorable conditions its growth is so luxuriant that insects 

 have little effect upon it unless they attack it in swarms. That is 

 what the alfalfa weevil does. After thousands of the adults which 

 emerge in June and July each year have died from various causes 

 during the summer and fall, there are still hundreds of thousands left 

 to spend the winter in each acre of the fields, and enough of them sur- 

 vive to produce astonishing numbers of eggs. Thus the total number 

 of larvae and eggs present in a measured area of a certain typical field 

 in 1913 was equivalent to 8,240,000 per acre on May 5 to 15,650,000 

 on May 14; to 22,920,000 on May 21; and to 10,410,000 on May 31, 

 while on June 5 the number had sunk to 310,000 per acre, because the 

 maturing of the larvse outran the deposition of eggs. 



The egg-laying begins in the dead stems which litter the ground, 

 weeks before the spring growth of the plants commences, and in fact 

 there are then many eggs remaining alive which were deposited the 

 fall before. Oviposition in green stems begins with warm weather 

 and increases until late in May and is so related to weather conditions 

 that the supply of young larvse is early and uniform in seasons when 

 the growth of the alfalfa is of that character, and late and concen- 

 trated when the growth of the crop is late. In either case the alfalfa 

 has no chance to mature a full crop. The larvae feed upon nearly 

 every leaf, and in the worst cases, completely stop the growth and 

 consume nearly everything but the woody fibres of the plant. The 

 hay must be cut green or abandoned. The feeding of the larvse does 

 not end with the attack upon the first crop; on the contrary, its effect 

 is intensified by concentration upon the buds of the stubble so as to 

 prevent the growth of the second crop. 



This condition exists, not occasionally but every year, throughout 

 most of the country where the weevil has become well established, 

 including six counties which produced in 1909, according to the U. S. 

 Census, oyer a quarter-million tons of alfalfa. It is a condition which 

 is likely to spread wherever alfalfa is grown, since Salt Lake is the 

 commercial and social center of a territory much greater than the 

 State of Utah or even the Great Basin. There is still the hope that 



