22 BORNED LABKS IN RELATION TO AGRICULTURE. 
injurious to cattle, produce- seeds which arc eaten by the horned 
larks. Lamb's quarters, buttonweed (fig. G), white top, and corn 
sparry arc among the other well-known weed seeds consumed. 
Fruit. 
A tew seeds of cultivated fruit- were found in the homed larks' 
stomachs. These were of blackberry, pear, and cherry. No fruit 
pulp was found, and the seeds were probably obtained from garbage 
heaps, where these birds sometimes feed. But one-fifth of 1 percent 
of the total food of the year is fruit, and nearly all of this is taken in 
the winter months. Evidently the horned larks have little taste for 
fruit, and the quantity they get is too insignificant to be of economic 
value. 
Miscellaneous Vegetable Food. 
Among the miscellaneous vegetable matter of no economic impor- 
tance eaten by the larks were bits of grass roots and stems, a few 
flowers, and fragments of other tissues of plants. One stomach con- 
tained algse, which had been obtained in a marsh. A few seeds, rec- 
ognizable onl} T as those of plants of the mint and carrot families, were 
found. Giraud reports that he found bits of seaweed in the stomachs 
of larks. 
In summing up this part of our subject it may be said that horned 
larks are among the most efficient weed-destroying birds, and. as we 
have just seen, not a few of the weeds they eat are among the worst 
pests of cultivated land. 
ANIMAL FOOD. 
The animal food of the horned lark, comprising 20.6 percent of the 
yearly diet, is made up entirely of invertebrates. It consists principally 
of insects, but is of great variety, as appears from the following list: 
Beetles, butterflies, grasshoppers, moths, ants, spiders. Hies, wasps, 
thousand-legs, mites, centipedes, snails, periwinkles, bits n\' crab, 
mussel, and oyster shell, earthworms, termites, and ant-lions. Not 
only arc the adult forms of the above eaten, but also the eggs, cocoons, 
and larvasof many of them. Thus the horned lark does effective work 
in thinning out many forms of invertebrate life. 
I \si:< TS. 
There are more harmful than beneficial families of insects, and the 
influence of t he injurious kinds great ly overbalances that of the others. 
Many species, however, are valuable allies of the farmer, and success- 
ful agriculture would be well-nigh impossible without them. For the 
purposes of economic ornithology, only a few groups are considered 
beneficial. Theseare chiefly the parasitic hymenoptera, which destroy 
many injurious insects, and the predaceous beetles. That the latter 
