3 io 



FUNDAMENTALS OF AGRICULTURE. 



of such fruit tree pests as the codling moth, the tent 

 caterpillar, the gypsy moth and the cankerworm, and 

 it is also destructive to bark borers and scale insects. 



The Tree Guardians. Among the birds that are 

 essential to the trees are the creepers and the kinglets, 

 the warblers, vireos, tanagers, orioles and the jays, 

 all of which excel in guarding the limbs and foliage of 

 trees against the attacks of many of the greatest insect 

 pests known. When the developing insects escape all 

 these and, assuming wings, launch out into the air they 

 are met by the flycatchers that, sitting on some van- 



Nestling. Adult. 



FOOD OF BANK SWALLOW. 

 I, Weevil; 2, ichneumon-fly; 3, winged ant; 4, fly; 5, dragon-fly; 6, stink-bug. 



tage point, pursue and catch them in the air, while 

 above and around all, sweep the swift swallows and 

 nighthawks that pursue their prey even into the upper 

 regions of the air. On the ground below, the thrushes, 

 sparrows, blackbirds and towhees pick up the insects 

 that fall to the ground, or they scratch for insects 

 among the dead leaves on the forest floor. All these 

 families of birds together form the inner and outer 

 circles that guard the tree, and all should be protected 

 by the farmer. 



EXERCISE. Make as complete a list as possible of the orchard 

 and woodland birds and their food. If one bird eats 150 insects a 

 day, how many insects will four birds eat in seven months ? 



