50 



BIRDS IX THEIR RELATIONS TO MAN, 



Forluiiately, ciil-woriiis and llicir allies Innii a large ])ro- 

 portioii of the food of many hirds. They are especiaUy used 

 by the old birds for feeding the nestUngs. 



The famihes of silk-spinning moths and their allies — for- 

 merly included under the Bombycidae, but now subdivided 



into many groups — include a 

 number of the most injurious 

 insects affecting fruit and shade 

 trees. The larvae of this group 

 are hairy caterpillars which 

 feed upon leaves, and when 

 fidl grown spin silken cocoons 

 for protection in the pupa state. 

 The tent cater})illar of the apple 

 and wild clierry, the fall web- 

 worm, the tussock-caterpillar, 

 and many similar insects be- 

 long here. One of the most 

 1 1 ( (tably destructive members 

 ol' the group is the gypsy 

 moth, recently so prominent 

 heforellie jjnblic in Massachu- 

 setts. The two sexes of the 

 adult moth in this species dif- 

 fer greatly : the general color 

 of the male is brownish and of the female whitish. The eggs 

 are laid in bunches in a great variety of situations, and the 

 resulting larvie feed upon the foliage of nearly every kind of 

 tree and shrub. 



Com})aratively few birds attack the hairy caterpillars of this 

 group, but some — as the cuckoos and blue-jays — devour them 

 eagerly. The European cuckoo is said to regurgitate the mass of 

 sivins thus swallowed ; probably our species have a similar habit. 

 The I;n'<'er bombycid caterpillars — like those of the cecropia 

 and polyphenujs moths — are eaten by some of the hawks. 



