STRUCTURE, GROWTH AND ECONOMICS OF INSECTS 39 



ing those in connection with natural forests and forest products, and 

 products in storage, which would make a probable total loss of over 

 one billion dollars. The losses are estimated at $1,182,000,000 for 

 1915, and $1,400,000,000 for 1917 (J. Ec. Ent., Feb., 1918). 



Estimates of the losses inflicted by insect pests on the farm products 

 of Canada are mainly based on similar ones for the United States. 

 At the present time it is difficult to form a reliable estimate of average 

 annual losses due to insects from Canadian records. In some of the 

 older provinces fairly complete records covering a series of years 

 are available, but in the newer provinces the records are incomplete. 



Estimates have been made of the losses from some of the more 

 serious pests that occasionally cause great damage, such as the Hessian 

 Fly and the Pea Weevil. In Ontario the loss from the Hessian Fly 

 in each of the years 1900 and 1901 was about two and one-half million 

 dollars, and from the Pea Weevil in 1902 over two millions. 



If, however, the percentage loss in the United States, viz., 10 per 

 cent, be taken as a fair basis for insect loss in Canada it can be readily 

 reckoned that the total loss every year in that country exceeds 100 

 milUons of dollars. 



Beneficial Insects 



While the damage done by insects is enormous it must not be sup- 

 posed that all insects are injurious. As a matter of fact there are more 

 insects that are either beneficial or non-injurious than there are in- 

 jurious forms. Man owes much to the beneficial insects for their good 

 service in keeping the injurious forms in check. 



The fact that most plants with colored flowers are largely dependent 

 upon the visits of insects for their fertilization and the setting of their 

 fruit should make it quite evident that insects play a most important 

 part in the economy of nature, and are no mean things after all. Let 

 one reflect for a moment on the loss to the world if the blossoms of apple, 

 plum, peach, grape, strawberry and raspberry among fruits were not 

 fertihzed by bees and wasps; if the clovers were not visited by 

 bees, and if the hundreds of beautiful wild flowers of the fields and 

 meadows were allowed to die without setting seeds. 



In addition, one should not forget the part played by scavenger 

 and carrion insects that feed upon dead and decaying organic matter. 

 They help to make our surroundings purer and cleaner. Besides, 



