276 



IRENE D. DOBROSCKY. 



and the writer based on material in the U. S. National 

 Museum: Brown thrasher, cardinal, cooper's hawk, 

 long-eared owl, cliff swallow, western robin, western 

 horned-lark. 



III. In addition those listed from California by O. E. Plath: 



Yellow warbler, green-backed goldfinch, willow gold- 

 finch, Nuttall sparrow, California purple finch, Cali- 

 fornia linnet, California brown towhee, rusty song 

 sparrow, Oregon towhee, russet-backed thrush, cedar 

 waxwing. 



IV. In addition those recorded by Bezzi: Bank swallow, 



swamp sparrow, white-throated sparrow, white-crowned 

 sparrow. 



V. Henshaw ('08) records: Woodpeckers. 



Since these parasites are so prevalent, no doubt in the course of 

 further investigation, many more species of birds will be found to 

 be parasitized. 



ECONOMIC IMPORTANCE. 



The results of the writer's collecting show the following amount 

 of infestation: 



The number of pupae in a nest varied. In robins' nests there 

 \vere from i to 20 pupae; from 10 to 50 were found in the bird- 

 houses of house wrens and bluebirds. Other nests, except those 

 of the crow, contained usually from i to 4 pupa.*. The crows' 

 nests however, contained anywhere from 20 to 343. The nest in 

 which the 343 larva of all sizes, were found, harbored three young 

 crows. These were much smaller and weaker than crows of their 

 age usually are. 



A parasite with such a wide range of valuable birds as hosts 



