THE CANADIAN ENTOMOLOGIST 67 



THE CASE OF VANESSA CALIFORNICA. 



BY E. J. NEWCOMER, STANFORD UNIVERSITY, CAL. 



The controversy between Prof. F. M. Webster and Dr. J. 

 McDunnough over the occurrence of Vanessa californica in North- 

 ern California and Southern Oregon, and regarding its larval food 

 plants, has interested me because I was in the region affected during 

 a large part of July, 1911. Their articles appeared in the Canadian 

 Entomologist for April, July and October of last year. - Without 

 antagonizing either gentleman by remarks concerning his state- 

 ments, let me give an account of what I saw and recorded. 



I spent two weeks, from the twelfth to the twenty-seventh of 

 July. 1911, near Susanville, in Lassen Co., California, only a hun- 

 dred miles or so south of Lakeview, Oregon, and in exactly the 

 same sort of region — namely, open, arid country, irrigated and 

 devoted largely to the raising of alfalfa, and bounded on the west 

 by the wooded range of the Sierra Nevada. At the end of the two 

 weeks, I went south through the Sierras for a hundred and fifty 

 miles. 



At Susanville, during the early part of my stay, I found 

 numerous patches of "buck brush" or "snow brush" {Ceanotluts 

 sp.) in the timbered regions literally alive with the black, spiny, 

 half-grown caterpillars 'of Vanessa californica. Frequently the 

 bushes would be practically stripped, and the caterpillars would 

 . be found migrating in search of other bushes. By the time I was 

 ready to start south, many of the caterpillars had pupated, and 

 there were a few adults flying about. I saw numbers of skeleton- 

 ized bushes with chrysalids suspended from their branches, and if 

 a bush were shaken or disturbed, the chrysalids immediately 

 started swinging back and forth, and would continue this motion 

 for several seconds, producing a curious rattling sound.- As I 

 went farther south, I saw more of the butterflies, but I did not 

 observe any large swarms, though a week or so later there were 

 accounts in various newspapers concerning these swarms, and they 

 were described to me by several persons who saw them. 



Xow for the worms which attacked the alfalfa and other field 

 crops. While I was at Susanville, a farmer, hearing that I knew 



February, 1914 



