78 BIRDS OF CALIFORNIA AFFECTING FRUIT INDUSTRY. 



nearly 69 percent. Lepicloptera in the adult form do not as a rule 

 constitute an important part of the diet of birds, but, with the excep- 

 tion of the flycatchers, the titmice perhaps eat the most. The greater 

 number consumed by these insects, however, are eaten as larvae — cat- 

 erpillars. A few, however, are eaten in the pupa state, and here the 

 bush tit has a good record. In a number of stomachs were remains 

 of the jmpae of the codling moth, one of the worst pests to the apple 

 industry. This insect is protected from the attacks of birds by its 

 peculiar mode of life. It passes the larval stage inside the apple. 

 The adult moth flies mostly by night and hides during the day. 

 When the larva is full grown it leaves the apple and seeks a place of 

 concealment, such as a crevice in the bark of the tree, a crack in the 

 trunk, or among rubbish on the ground, where it changes to a chrys- 

 alis. It is in this stage that the insect is most vulnerable to the 

 attacks of birds, and as the whole family of titmice get most of their 

 food by searching in just such places as those used for concealment by 

 the larva, it is not surprising that they find and devour many of them. 



The cocoons of certain tineid moths are a very constant, though not 

 large, component of the food of the bush tit. The larvae of many of 

 the Tineina are leaf -miners, and therefore injurious when attacking 

 economic plants. 



Strangely enough, wasps and ants (Hymenoptera) are nearly absent 

 from the food of this bird. The total amount for the year is less 

 than 1-| percent. In view of the fact that ants are always crawling 

 over the trunks and branches of trees, the very places where the tits 

 feed, it seems strange that so few of them are eaten. Moreover, 

 plant-lice always have ants in attendance upon them, and when tits 

 eat so many plant-lice it is rather remarkable that they should not 

 take some of the ants also, as do the smaller woodpeckers, whose food 

 habits are in many respects so similar. In 353 stomachs only two 

 ants were identified, one in the adult and one in the pupal stage, and 

 these were in separate stomachs. In IT other stomachs a few frag- 

 ments of what probably were small wasps were found, which make up 

 the total of the hymenopterous diet of the bush tit. 



The remaining animal food of this bird, about 8 percent, is com- 

 posed of various insects, such as a few flies, a few bits of grasshoppers, 

 insects' eggs not further identified, with a considerable number of 

 spiders. That the tits should not eat grasshoppers is not surprising, 

 as these insects do not commonly infest trees where the birds feed, 

 and as a rule they are rather large game for such small birds. The 

 great bulk of the 8 percent, however, consists of spiders, which con- 

 stitute a constant item of food in every month. Quite a number of 

 pseudoscorpions also were found in the stomachs, but, owing to their 

 minute size, the percentage is not very noticeable. 



