CHAPTER VII. 



INSECTS INJURIOUS TO VEGETABLES. 



In this chapter only the more common insects infesting 

 garden vegetables are referred to. There are many others that 

 almost yearly cause some damage to our crops and which in 

 occasional years cause serious loss. But to enumerate them 

 would require more space than can he afforded here. In dealing 

 with them it is well to remember that biting insects, such as 

 potato beetles and blister beetles, are generally most surely de- 

 stroyed by arsenical poisons such as Paris green and London 

 purple; while sucking insects, such as plant lice and chinch 

 bugs are not affected by them but are most readily destroyed by 

 external applications such as tobacco water and kerosene emul- 

 sion. We should also remember that in our war upon injurious 

 insects we have the support of most of the birds and of the moles 

 and shrews, and these should be protected as the friends of 

 man rather than be destroyed as is too often the case among 

 thoughtless or ignorant people. Moles and shrews are especially 

 useful since they work under ground, and feed largely on various 

 insects that are difllcult to destroy on account of their living 

 in the soil. It is perhaps no exaggeration to say that the shrew 

 (often called mole) will eat its weight of insects each day. In- 

 sects are also liable to attacks of parasites or of fungus and 

 other diseases, which destroy them in large numbers and often 

 in a very short time. 



When insects appear in small numbers hand picking is often 

 a very efficient remedy, but when they become very abundant 

 some other method of destroying them must be devised. 



INSECTICIDES AND METHODS OP DESTROYING INSECTS.. 



Pyrethrum is the insect powder of the stores. It is made 

 by grinding the flowers of the pyrethrum plant which closely 

 resembles the common oxeye daisy. It is not poisonous to higher 

 organized animals although very destructive to many kinds of 

 Insects. It is frequently adulterated and can seldom be obtained 



