100 



BIEDS OF CALIFORNIA AFFECTING FRUIT INDUSTRY 



stomachs of the Arctic bluebird (Sialia arctica) were obtained. 

 They were taken in fall and winter, and, while so small a number is 

 not sufficient for positive conclusions, it may be said that the charac- 

 ter of the food closely resembles that of the other species in the same 

 months. 



The two species eat about the same proportion of animal and vege- 

 table food; the animal part consists of the same orders of insects, 

 while the vegetable part is made up of the same varieties of fruit. 

 In short, it may be said that if there are important differences in the 

 food habits of the two birds the evidence at hand fails to establish 

 the fact. 



SUMMARY. 



It seems scarcely necessary to comment on the foregoing statements 

 with regard to the bluebird's diet in its economic relations. That the 

 bird is an eminently useful species is so patent that it hardly needs to 

 be pointed out. Whatever harm fruit growers have suffered from 

 birds, none of it can be laid at the door of the bluebird. 



List of insects identified in stomachs of bluebirds : 



CoccineUa t. calif ornica. 

 Hippodamia con vergens. 

 Polijcaon stout ii. 

 Aphodius rugifrons. 

 BJapstinus dilatatus. 



COLEOPTERA. 



BJapstinus sulcatus. 

 Blapstinus puJveruJentus. 

 Rliigopsis effracta. 

 Balaninus sp. 

 Sitones sp. 



Saissetia olea\ 



HEMIPTERA. 



Sinea diadema. 



HYMENOPTERA. 



llessor and re i (ant), 



Insects also were identified as belonging to the following families 



COLEOPTERA. 



Carabidse. 



Stapbylinida?. 



Coccinellida?. 



Histerida?. 



Elaterid^e. 



Buprestida?. 



Lampyrida?. 



Reduviida?. 

 Capsid?e. 

 Lygseidse. 

 Pentatoinidse. 



Ptinidse. 

 Scarabaeidse. 



Cerambycid?e. 

 Cbrysomelida?. 

 Tenebrionida 3 . 

 Ptbyncbopbora (superfamily) , 



HEMIPTERA. 



Coriinelrenidge. 

 Scutellerida?. 

 Jassidse. 

 Coccidse. 



