346 THE CANADIAN ENTOMOLOGIST 



that live about the shores of the lakes and rivers that these fish 

 frequent. Even the larvae of the troublesome mosquito serve 

 in this way a useful purpose. Both domesticated and wild fowl 

 feed to a great extent upon insects, the latter especially during 

 the nesting season. So without taking time to go more into 

 details we see that many insects may be friends in this important 

 matter of providing food for us. 



A third manner in which insects may act as our friends is as 

 scavengers. If all the dead animals and plants, including trees, 

 of course, were to lie undestroyed on the surface of the earth, they 

 would soon make an intolerable condition of afifairs. But in the 

 summer no sooner does an animal or plant die than there gather 

 to it various insects that quickly hasten the process of decay. 

 Some of the insects that feed on dead animals are carrion beetles, 

 rove beetles, blow-flies and flesh-fiies. Any one who has watched 

 how quickly a dead horse or smaller animal becomes a seething 

 mass of insect life will readily understand why it has been said 

 that a blow-fly can destroy a dead ox as quickly as a lion. 



In the case of trees we have all seen beautiful pines that have 

 been cut down or fallen and allowed to lie for a year or two in the 

 forest, and then, when they are examined, are found to be 

 perforated in numerous places by borers. These borers are the 

 larva? of certain kinds of beetles, chiefly long-horned beetles. We 

 feel disappointed at the injury to the tree, but in nature the insects 

 while feeding themselves on the wood are at the same time serving 

 a useful purpose, because these holes allow the more rapid and 

 deep entrance of diseases and so hasten greatly the rate of disintegra- 

 tion of the tree. We see, therefore, that insects help us greatly 

 by removing dead animals and plants, and thereby giving back to 

 the earth the substances of which they are composed and at the 

 same time making room for other animals and plants to take their 

 place. 



The fourth way in which insects serve as friends is by many 

 useful kinds helping to control injurious kinds. One class of 

 insect that helps in this way is known as parasites, and another 

 as predaceous insects. The latter merely capture their victims 

 and feed on them as a lion would capture and devour a smaller 

 animal, but the former kind pass all their larval stage either in or 



