358 ECONOMIC IMPORTANCE OF ANIMALS 



An insect friend of man. An ichneu- 

 mon fly boring in a tree to lay its eggs in 

 the burrow of a boring insect harmful to 

 that tree. 



does man considerable good because of its habit of laying its eggs 



and leaving its young to develop in the bodies of caterpillars 



which are harmful to vege- 

 tation. Some of the ichneu- 

 mons even bore into trees in 

 order to deposit their eggs in 

 the larvae of wood-boring 

 insects. It is safe to say that 

 the ichneumons save millions 

 of dollars yearly to this 

 country. 



Usefulness of the Toad. — 

 The toad is of great economic 

 importance to man because of 

 its diet. No less than eighty- 

 three species of insects, mostly 

 injurious, have been proved to 

 enter into the toad's dietary. 

 A toad has been observed to 



snap up 128 flies in half an hour. Thus it could easily destroy 



very many insects during a day and do an immense service to 



the garden during the summer. Toads also feed upon slugs and 



other garden pests. 



Food of Snakes. — Probably 



the most disliked and feared of 



all animals are the snakes. 



This feeling, however, is rarely 



deserved, for, on the whole, our 



common snakes are beneficial 



to man. The black snake and 



the milk snake feed largely on 



injurious rodents (rats, mice, 



etc.), the pretty green snake 



eats injurious insects, and the 



little DeKay snake feeds partly on slugs. If it were not that 



the rattlesnake and the copperhead are venomous, they also 



could be said to be useful, for they devour English sparrows, 



rats, mice, moles, and rabbits. 



The common toad, an insect eater. 



