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. Xev.. 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 Xashville. Tenn.. and 
at Greenwood. Miss. Here the butterflies were abroad from early 
April until late Xovember and. while everywhere present, never 
seemed to do a great amount of damage. Mr. YT . H. Larrimer. also 
working at Xashville. reported larva? in considerable numbers. 
ECONOMIC HISTORY IX CALIFORNIA AND ARIZONA. 
It was Henry Edwards x who. in 1877. reported the occurrence at 
various times of what since has proved to be one of the many color 
forms of this species. Xo 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 Eiver 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 caterpillars 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." TTe 
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. Cal.. 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. 
- Cockerell. T. D. A. Some insect pests of Salt River Valley and the remedies for them : 
Ariz. Expt. Sta. Bui. 32. p. 2S6-28S, Dec, 1S99. 
