46 



NATURAL ENEMIES OF INSECTS 



Scores of species depend largely on insects for their food during a part 

 of the 3^ear, if not throughout all of it. Among our best friends are 

 the swallows, chickadees, cuckoos, the kingbird, catbird, robin, blue- 

 bird, and the woodpeckers ; but this list is merely suggestive. 



Birds are peculiarly fitted for dealing with outbreaks of injurious 

 insects. Possessed of the power of flight they can flock to places where 

 insect pests that they enjoy are in abundance. At the same time 

 they are not bound to maintain a species at reasonable abundance 

 in order to protect their source of food and keep it from disappearing 

 entirely, as is the case with many insect parasites. 



Toads are entitled to prominent rank as destroyers of insects. The 

 number of specimens consumed by them in a season is enormous. Other 

 animals that live on insects to a considerable extent are skunks, moles, 

 and field mice. 



Efficient enemies of aquatic insects, or of such as spend part of their 

 life beneath the water, are various species of fishes. 



Predaceous and Parasitic Insects 



The greatest inroads in the ranks of injurious insects are made by 

 other members of the same great class itself, by the predaceous and 

 parasitic insects. 



In general, we speak of predaceous insects as those that attack 

 and feed on other insects or animals of various species, but are not 

 dependent on a single individual 

 host for their existence. Thus 



Fig. 



46. — A predaceous bug, Sinea 

 diadema Fab. Original. 



Fig. 47. — Adult Braconid. 

 An egg parasite. Enlarged 

 and natural size. Original. 



