36 B. C. ENTOMOLOGICAL PROCEEDINGS, 1912. 



In any discussion of beneficial insects those that act as poUenizers 

 deserve a large place. Bees, wasps, moths, butterflies, a number of 

 bugs, some flies, and a few beetles take part in this work, so essential to 

 most plants of economic importance. The red clover for instance can- 

 not set its seed without the aid of the bumble bee, while the apple, pear, 

 and many other Rosaceous plants depend very largely upon the honey 

 bee for pollenation. The benefit that insects do in this way is incalculable 

 and does much to counterbalance the ravages of injurious forms. Darwin 

 was the first to prove experimentally that as a rule cross-fertilization 

 is indispensable to the vigour of plants, and in his great work. Cross 

 and Self Fertilization in Plants, cites many marvellous instances of 

 plant adaptation to insure cross-fertilization by insects. A study of 

 these adaptations, and of the part that insects have indirectly played, in 

 the evolution of the plant kingdom is one of great fascination. It is, 

 however, outside the scope of my present subject. 



As scavengers insects are also of considerable service to man. They 

 destroy vast quantities of dead and decaying animal and vegetable matter 

 which, if left to accumulate, would soon render the globe uninhabitable. 

 By breaking down organic matter in this way, as well as in many other 

 respects, insects play important parts as makers of soil. They open it 

 up to the action of the air by burrowing through it in all directions, 

 bring up subsoil to the surface, carry vegetable matter below ground, 

 and on dying yield their own bodies to further influence the changes 

 that go on in the soil. 



The work of insects in destroying noxious weeds is also worthy of 

 mention. An interesting case of this came under my notice last fall. 

 In attempting to collect a supply of seeds of the common Canada thistle 

 I found every head the habitat of a small maggot, and had difficulty 

 in getting a sound seed in the whole district. 



Examples of this class are: The milkweed butterfly {Anosia 

 plexippus) ; the thistle butterfly (Pyramris cardui) and the purslane 

 Sphinx moth (Deiliphila lineata.) 



Commercially, insects and insect products have a varied and e.xten- 

 sive use. Furnishing us with an article of dress and forming the basis 

 of an important industry, we have the silkworm (Bombyx mart). The 

 dessicated bodies of a scale insect. Coccus cacti, yields us cochineal, and 

 another scale insect, Tacchaldia laccn, supplies us with the lac of 

 commerce. 



This subject would be incomplete without "^ome mention of 

 insects and their products as food. The first insect that naturally 

 suggests itself in this connection is the honey bee, which is one of our 

 oldest domesticated animals. Locusts from time immemorial have been 



