48 BIRDS OF CALIFORNIA AFFECTING FRUIT INDUSTRY. 
soon acquire the habits of its eastern relative. From the material at 
hand this warbler appears to be even more exclusively insectivorous 
than the species last discussed. This may arise from the fact that 
it stays in the fruit districts during summer, when insects are most 
numerous; but it must be remembered that this is also the season 
when fruit and vegetable food generally are most abundant. 
William Prond, of Chico, Butte County, thus recounts the efficient 
service of this and other warblers: 
On Rancho Chico is a fine coNection of roses, all of which are more or less 
liable to attacks from ulphis rosea, but are perfectly free from other insects. 
I attribute this to the protection of sinall birds, among the most active of which 
are Dendroica wstiva, * * * Helminthophila celata, Regulus calendula. 
The following statements in regard to the food of the summer 
warbler are based on the examination of 98 stomachs, ‘all collected 
from April to October, inclusive. 
Animal food—The animal food, composed entirely of insects and 
a few spiders, amounts to over 97 percent. The largest item is 
Hymenoptera, which amounts to over 30 percent, about half of which 
are ants. The remainder are small bees and wasps, some of which 
are probably parasitic species, though none were positively identi- 
fied. The insects of this order must be favorite food, as they are 
eaten with remarkable regularity and constitute an important per- 
centage of the diet in every month represented. Caterpillars, with a 
few moths, aggregate over 18 percent. The greater number are 
eaten in spring and early summer, but in fall they give place to other 
insects. 
Beetles form nearly 16 percent of the diet, and embrace about a 
dozen families, of which the only useful one is that of the ladybirds 
(Coccinellide), which are eaten to a small extent. The great bulk 
of the beetle food consists of small leaf-beetles (Chrysomelide), with 
some weevils, and several others. One stomach contained the remains 
of 52 specimens of Votowus alameda, a small beetle living on trees. 
Bugs (Hemiptera) constitute over 19 percent of the food, and are 
eaten regularly every month. Most of them consist of leaf-hoppers 
(Jasside) and other active forms, but the black olive seale appeared 
in a number of stomachs. Plant-lice were not positively identified, 
but some stomachs contained a pasty mass, which was probably made 
up of these insects in an advanced stage of digestion. 
Flies seem to be acceptable to the simmer warbler; they are eaten 
to the extent of nearly 9 percent. Some of them are of the family 
of the house fly, others are long-legeed tipulids, but the greater num- 
ber were the smaller species commonly known as gnats. A few 
small soft-bodied Orthoptera (tree-crickets), a dragon-fly, and a few 
remains not identified, in all about 5 percent, made up the rest of 
the animal food. 
