348 THE CANADIAN ENTOMOLOGIST. 



lustration of many that could be used to show the good predaceous 

 insects do. 



The more one studies insects and thinks over what takes place, 

 the more inclined he is to feel that were it not for our insect friends 

 our insect foes would make this earth almost or quite uninhabitable 

 for man. I do not mean, however, that insects are the only forces 

 at work in controlling our foes, because disease also plays a great 

 part, as do also extremes of heat and cold and several other things. 



We must pass on now to consider briefly our insect foes. 



Insect Foes. 



There is no doubt that injurious insects every year take a 

 large toll from farmers and especially from fruitgrowers. As there 

 is not time to discuss many of these insects, we shall devote our 

 attention first to our worst two orchard insects, and then to a few 

 of the chief pests of the field crops. 



There are many insects that attaclc fruit trees, but two of 

 these stand out prominently for their powers of destruction. These 

 are the San Jose Scale and the Codling Moth. The former is the 

 most destructive insect pest ever introduced into the province, 

 but fortunately, though it has been here for twenty years, it has 

 not spread beyond the south-western counties. It is a very small 

 insect, circular, and when full grown, has about the same diameter 

 as the head of a pin. Its powers of reproduction are wonderful: 

 from a single female there may be more than a million offspring 

 by the end of the year. As all of these attach themselves to the 

 trunk, branches, twigs, leaves or fruit and suck the juices, they 

 soon do a great deal of harm. Any orchard that becomes infested 

 with this pest in the warmer parts of the Province, and is not 

 sprayed, is doomed to complete destruction in a few years, even 

 the largest apple trees being killed. An exception to this statement 

 should be made in the case of sour cherries and to some extent of 

 Kieffer pears, the former being immune and the latter not often 

 severely attacked. Up to the present time there have been only 

 a few parasites attacking this scale in Ontario, but we are hopeful 

 that these will become abundant in a few years. We have en- 

 deavoured to hasten the process by introducing parasites from 

 Pennsylvania, where they are doing much good. In the meantime 



