210 BOARD OF AGRICULTURE, 



len of some other flower of the same species. If insects are 

 excluded from such plants as require their aid, they produce 

 little or no seed. If the bees and other insects were kept 

 from the flowering orchards, the autumn would see them 

 more destitute of fruit than they have ever been from the 

 ' attacks of the curculio. The honey and pollen which the 

 insects gather, is of course all that attracts them to the flow- 

 ers ; in fact the special office of the honey is to attract insects 

 that they may bear away the pollen and fertilize the seed. 

 As far as we yet know, only those plants which require insects 

 to fertilize them produce honey. Much yet remains to be 

 learned of the exact way in which fertilization is accomplished 

 in many special cases, but all observations go to show that in 

 the majority of cases insects are necessary to accomplish it. 



I trust I have said enough of the beneficial species to prove 

 that we should by no means condemn all insects alike, that, 

 while insects do us an enormous amount of damage, many of 

 them are most useful to the farmer and are even a necessity 

 to him. It is undoubtedly true that in the natural state of 

 any region the injurious species would never increase to the 

 extent to which they do in our cultivated fields. Before man 

 interferes with the vegetation of the country, a great variety 

 of plants grow together in the same region, and any insect, 

 feeding on a particular species of plant, must go about from 

 place to place in search of its particular food plant ; and 

 should it increase in numbers, its food plant at once becomes 

 scarce and it must decrease ; in the same way the insect and 

 its parasites hold each other in check, and a balance of power 

 is kept up between the insect, food-plant, and parasites. 



Having acknowledged that many insects are beneficial, the 

 importance of distinguishing between the iiijurious and bene- 

 ficial species is at once apparent. The importance of the 

 farmer himself being able to make this distinction is well illus- 

 trated by the mistakes which are constantly made. The rav- 

 ages of the plant lice, or aphides, are familiar to all of you. 

 The rapidity with which they multiply render them most dififi- 

 cult to combat. They hatch out in the spring from eggs pro- 

 duced by winged parents of the fall before. The spring brood 



