20 BIRDS OF CALIFORNIA AFFECTING FRUIT INDUSTRY. 



animal and vegetable matter gives 78 percent of the former to 22 

 percent of the latter, exactly the same as in the case of the hairy 

 woodpecker. 



Animal food. — Of the animal food, beetles are the largest item, 

 and amount to nearly 34 percent. They consist largely of larval 

 Cerambycidae, or borers. While not so good a driller for insects as 

 the hairy, the efforts of the Nuttall are not to be despised. It destroys 

 a goodly number of wood-borers, but it eats more adult beetles of other 

 families than do either of the species whose food has been discussed. 

 A considerable number of small leaf beetles (Chrysomelidse) are eaten 

 by the Nuttall, and are probably taken from leaves. It eats also 

 click beetles (Elateridge) , darkling beetles (Tenebrionidse) , and 

 weevils (Rhyncophora), among which the genus Balaninus, that 

 preys upon acorns and other nuts, was identified. A few predaceous 

 ground beetles (Carabidse) were found. 



Ants do not appear to be a favorite food of this woodpecker, and 

 they were eaten very irregularly. They constituted 36 percent of 

 the food in June, 22 percent in September, and appear in small quan- 

 tities in January and August, but are completely wanting in the other 

 months. The average for the year is less than 6 percent. Other 

 Hymenoptera form practically the same percentage, but nearly all 

 were contained in a single stomach taken in December. 



Hemiptera (bugs), like ants, are taken very irregularly and occur- 

 either in considerable quantities or not at all. In January they 

 amount to 46 percent of the food of the month, in February to 28 

 percent, in June to 10 percent, in July to 36 percent, but in the other 

 months do not appear. The average for the year is 1 1 percent. They 

 belong to several families, but no special pest is prominent. Scales 

 were found in two stomachs and plant lice in one. Three stomachs 

 contained remains of the box-elder bug, Leptocoris trivittatus, of 

 which two stomachs contained between 30 and 40 specimens each. 

 This bug is very abundant in some places at times, and injures the 

 box-elder tree. It has also done some damage to fruit. 



Diptera (flies) were found only in the stomachs taken in June. 

 They amounted to 12 percent for that month or 1 percent for the 

 whole year. 



Caterpillars stand next to beetles in the quantity eaten by the 

 Nuttall woodpecker. They amount to over 13 percent of the food, 

 and, except in the three winter months, appear very regularly. 

 Many of them are of the wood-boring kinds, but leaf-eaters also are 

 present. Various other insects, insects' eggs, and a few spiders 

 amount to 7 percent, and complete the animal food. 



Vegetable food. — Fruit amounts to 11 percent, or half of the vege- 

 table food. Naturally most of it was taken during the summer and 

 fall months, although the one stomach taken in December contained 



