4 BULLETIN" 124, U. S. DEPARTMENT OF AGRICULTURE. 



gate on different parts of the field, and wherever they are the crops 

 are totally destroyed." The same month Mr. Frank C. Jones, of 

 Gardnersville, Nev., reported : " The caterpillar of the yellow butter- 

 fly is seriously damaging the alfalfa fields of Carson Valley. It 

 seems to develop most abundantly about the time of the first cutting 

 and feeds on the young shoots, retarding the growth perhaps two 

 weeks." 



During the season of 1913 the species was reported by Mr. E. H. 

 Gibson as doing slight damage at Jackson and Nashville, Tenn., and 

 at Greenwood, Miss. Here the butterflies were abroad from early 

 April until late November and, while everywhere present, never 

 seemed to do a great amount of damage. Mr. W. IT. Larrimer, also 

 working at Nashville, reported larvae in considerable numbers. 



ECONOMIC HISTORY IN CALIFORNIA AND ARIZONA. 



It was Henry Edwards x who, in 1877, reported the occurrence at 

 various tinies of what since has proved to be one of the many color 

 forms of this species. No account can be found in which he treats 

 the species as of economic importance, but he says: "This * * * is 

 an abundant insect in clover and alfalfa fields from July to Septem- 

 ber," thus intimating that its numbers might be great enough to 

 cause damage. Most of his records were for California. 



In 1899 Prof. T. D. A. Cockerell, 2 in studying the insects of the 

 Salt River Valley of Arizona, noted the abundance of these butter- 

 flies, but did not stress the probability of damage to alfalfa. He 

 says: "I never saw these butterflies so extraordinarily abundant as 

 they were last October at Phoenix. * * * These cateqDillars be- 

 ing very numerous must eat a great many leaves and so reduce the 

 crop, but it is probable that their ravages would not be very notice- 

 able under favorable conditions of moisture and temperature. At all 

 events, it is not practicable to take any measures against them." We 

 have here the first record of the insect as actually destructive to 

 alfalfa. 



It would seem that after this, as irrigation in the warm valleys of 

 southern Arizona and southern California began to be more highly 

 developed and alfalfa became a more important crop, the damage 

 became more noticeable each year. In 1907 Mr. Geo. G. Carr, writ- 

 ing to the Department of Agriculture from Hanford, Cab. reports 

 considerable damage to alfalfa. An extract from his letter follows : 



1 Edwards, Henry. Pacific Coast Lepidoptera, No. 24. Notes on the genus Colias, with 

 descriptions of some apparently new forms. In Proc. Cal. Acad. Sci., v. 7, p. 4. Feb. 5, 

 1877. 



2 Cockerell, T. D. A. Some insect posts of Salt River Valley and the remedies for them: 

 Ariz. Expt. Sta. Bui. 32, p. 286-288, Dec, 1899. 



