42 BIRDS OF CALIFORNIA AFFECTING FRUIT INDUSTRY. 



In the laboratory investigation of the food of the western fly- 

 catcher 141 stomachs were examined. They were collected from 

 March to October inclusive, and probably give a fair idea of the 

 bird's food for these months. Analysis gives 99.28 percent of animal 

 food to 0.72 percent of vegetable; in other words, there was less than 

 three-fourths of 1 percent of vegetable matter. Only one other 

 flycatcher, the western wood pewee, eats so little vegetable food. 



Animal food. — In this analysis a separate account was kept of 

 the ladybird beetles (Coccinellidse) . This bird appears to eat more 

 of them than does any other flycatcher, but the number for the 

 whole season is not large enough to be very serious. The greatest 

 consumption occurred in August, a little more than 7 percent. The 

 average for the season is 2\ percent. Other beetles amount to 

 nearly 6 percent, nearly all harmful, the exception being a few 

 ground beetles (Carabidse) . 



Hymenoptera form the largest constituent of the food of this as 

 of most other flycatchers. They amount to over 38 percent, and are 

 an important item during every month of the bird's stay on its sum- 

 mer range. The highest percentage is in March, 61 ; but as only 

 3 stomachs were taken in that month, the record can not be con- 

 sidered as final. June shows 52 percent, and is probably nearer the 

 true maximum, although August and September do not fall much 

 below. Ants were found in 14 stomachs, and parasitic Hymenoptera 

 in but 2. Hymenoptera in general were found in 99 stomachs, and 

 6 contained nothing else. No honeybees were identified. 



Hemiptera (bugs) amount to nearly 9 percent of the food. They 

 were found in 49 stomachs, 2 of which were entirely filled with them. 

 The greatest number were taken in August, when they constituted 

 29 percent. The following families were identified: 



Stink-bug family (Pentatomidse). Leaf hopper family (Jassidae). 



Chinch-bug family (Lygseidae). Tree-hopper family (Membracidae). 



Leaf-bug family (Capsidae). 



Diptera amount to a little more than 31 percent of the whole food. 

 They rank next to Hymenoptera, and, like those insects, are taken 

 very regularly during every month of the bird's stay in the State. 

 While October is the month of maximum consumption, 47 percent, 

 several other months are but little below. Only 3 families were 

 identified : The crane flies (Tipulidse) , the soldier flies (Stratiomyiidse) , 

 and the house flies (Muscidse). 



Lepidoptera, in the shape of moths and caterpillars, amount to 

 about 7 percent for the year, and were found in every month except 

 March. They appeared in 36 stomachs, of which only 7 contained 

 the adult insects — moths — and 29 the larvae or caterpillars. This 

 taste is in contrast with that of the black phoebe and the wood pewee, 



