288 FARM FRIENDS AND FARM FOES 



What is true of the relations between insects and birds 

 in orchards of deciduous fruits is equally true in orchards 

 of citrous fruits. Wherever oranges, lemons, and related 

 trees are grown for profit, hosts of insect enemies attack the 

 trees. These insects are preyed upon by birds which help 

 greatly in checking the injuries of the pests. 



Aerial Insects 



Nearly all the insects that affect orchards exist part of 

 their lives in a winged condition in which they fly through 

 the air from branch to branch or from tree to tree. At 

 such times they are in danger of being snapped up by 

 flycatchers, vireos, swallows, and other birds. Most of 

 these keep watch over comparatively limited spaces near 

 the trees, but the whole realm of the air is patrolled 

 by the swallows. Over the water or above the land the 

 flying insect is in danger of being suddenly captured in the 

 swallow's beak. The food of swallows consists chiefly of 

 insects thus caught upon the wing ; beetles, flies, ants, and 

 small moths are all taken in great numbers. Consequently, 

 these birds are as useful as they are beautiful, and should 

 be encouraged by every one. 



At night, also, the war against flying insects is kept up 

 by the whippoorwills and nighthawks. These interesting 

 birds patrol the air in dusk and darkness, catching flying 

 insects of many kinds in their capacious jaws. 



Other Enemies 



There are other enemies of orchard trees besides the in- 

 sects. The trunks are frequently girdled by meadow mice 

 and-rabbits that gnaw the bark. This generally happens 

 in winter, when the mice work beneath the surface of the 



