316 ILLINOIS STATE HORTICULTURAL SOCIETY. 



the Proctotrupidag ; and from these we have reason to believe that insects 

 in their imago state are for the most part exempt. On the other hand, 

 the subterranean larvje which, in a great measure, are out of the reach of 

 birds, are extensively preyed upon by the numerous kinds of ground 

 beetles and their larvae, which occupy the same territory with themselves. 



But the prosecution of this department would carry us too far from 

 our main topic, and we pass on, therefore, to consider another branch of 

 the subject. 



We have stated above that the extensive cultivation of certain fruits 

 and grains has been followed by a very natural consequence, but one 

 which no one probably foresaw, namely, the more than co-extensive 

 increase of some of those species of insects which naturally feed upon 

 them. To such an excess has this multiplication of certain kinds of 

 insects gone, that the production of some of our most valuable crops has 

 been rendered, in some seasons and localities, either a partial or a total 

 failure. 



In treating of birds the interesting question arises whether there have 

 been any similar instances of the excessive increase ot the granivorous and 

 frugivorous birds. The consideration of this question will bring us 

 directly to the subject of the most immediate practical importance, 

 whether any species of birds are actually found to be so numerous, or so 

 injurious, as to require their destruction, and whether such destruction is, 

 upon the whole, advisable. 



Some birds, like some insects, are remarkably prolific, though why 

 they should be more so than other species, closely related to them, it is 

 impossible for us to tell. There are insects so nearly allied to the potato 

 beetle, and to the chinch bug, that it requires pretty close observation to 

 tell them apart, and yet they are only known as comparatively rare insects. 

 So the wild pigeons sometimes congregate so as to break down the branches 

 of forest trees by their weight ; whilst the nearly-related ground-dove is 

 only seen in pairs, here and there, gleaning their subsistence by the road- 

 side. The black birds and rice buntings are also often seen in very large 

 flocks; but the corn and rice crops upon which they depredate are so 

 abundant, that these birds do not make any very serious impression upon 

 them. How trifling is the amount of damage caused by these most pro- 

 lific of birds, when compared with that effected by some of the more de- 

 structive species of noxious insects. Two obvious reasons occur to us why 

 birds do not go on, like insects, increasing almost indefinitely: First, 

 that birds rarely lay more than four or five eggs, whilst insects often lay 

 four or five hundred ; and secondly, insects lie dormant through the 

 winter months, and require no food, whilst birds have to migrate to 

 different localities, and run all the risks of an insufficient supply of food, 

 when removed from the abundant harvests among which they have been 

 reared. 



But it is more particularly the fruit-eating birds which have excited 

 the apprehensions of the horticulturists, especially those which feed upon 

 the smaller and more delicate fruits, such as cherries, grapes, and the 

 several kinds of berries ; a class of fruits which are not usually raised in 



