450 STATE POMOLOGICAL SOCIETY. 



knows, in a general way, that birds are one of the great instrumentalities 

 of nature for keeping in check the various tribes of insects, but no one, who 

 has not examined the subject, is aware of the extent and importance of this 

 agency. Almost all the land birds, except the larger birds of prey, subsist 

 wore or less upon insects, and more than half of them live upon insects either 

 chiefly or exclusively. The land birds, with respect to their food, may be 

 divided into three classes, the omiiivoro2is, the insectivorous, and the qranivor- 

 ous. The following are the principal omnivorous families : The starlings, the 

 orioles, the blackbirds, the crows, and the jays, the bomhy-cillcc, or cedar-birds, 

 and the titmice. These birds, as a general rule, feed indiscriminately upon 

 berries, seeds, and insects. 



The principal insectivorous families are the night-hawks, the swallows, the 

 shrikes, the fly-catchers, the sylvice, or warblers, the wrens, the sialietce, or blue- 

 birds, the creepers, and the woodpeckers. 



All these birds live exclusively, or almost exclusively, upon insects. A few 

 of them are sometimes seen to glean a few ripe berries in their season; but 

 these instances are exceptional to their ordinary habits. 



The granivorous families are the sparrows or finches, the buntings, the 

 tanagers, the grosbeaks, and the gallinacece, or birds of the poultry kind, includ- 

 ing the various kinds of grouse and partridges. It is a note-worthy fact, 

 however, that a large portion of these birds, which are classified as being 

 pre-eminently granivorous, are also largely insectivorous; and indeed most of 

 them feed their young almost exclusively upon the larvfe of insects. 



It is evident, therefore, that in the economy of nature birds are the natural 

 antagonists of insects ; and when we consider Avhat wide devastation a single 

 species of insect will sometimes effect, when it multiplies to excess, we can 

 not doubt that if the agency of birds should cease, every green thing on the 

 face of the earth would be destroyed by the numberless tribes of insects. 



This is the general view of the subject; but when we come to look at the 

 matter more particularly, some striking and exceptional facts present them- 

 selves. Though, as we have seen, birds present a suflBcient antagonism to 

 insects in the state of nature, they fail to furnish an adequate check to the 

 excessive multiplication of insects which has been induced, in certain cases, by 

 human intervention. The extensive cultivation of certain grains, fruits, and 

 vegetables, has been followed by a proportional, and sometimes much more 

 than proportional, increase of some of those species of insects which subsist 

 npon them. But there being no species of birds which are the special antag- 

 onists of these particular kinds of insects, there has been no corresponding 

 increase of insectivorous birds. Accordingly, we find that in reducing the 

 numbers of many of those species of insects which are most injurious to the 

 farmer and horticulturist, birds afford so little aid that, in the practical treat- 

 ment of the subject, they may as well be thrown wholly out of account ; whilst 

 in the case of others, they furnish us with a partial but inadequate assistance. 

 In the last category are to be placed some of the exposed leaf-eating caterpil- 

 lars, such as the tent caterpillar and the canker worm, which have been known 

 in particular localities, to have their numbers materially reduced by certain 

 species of birds. But if we take such examples as the chinch bug, the Col- 

 orado potato beetle, the plum curculio, the Hessian fly, and the bark louse, we 

 shall find that so far from feeding largely upon any of these insects, birds 

 scarcely touch them. The Hessian fly is too small to be sought after by birds 

 as a means of subsistence ; although a similar insect, the wheat midge, is stated 



