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covering tlie trunks of trees with a sticky or poisonous wash 

 to prevent the borer from entering. All preventive applica- 

 tions must be made just before the adult insect appears, and 

 must be kept up at frequent intervals as long as the adult 

 is in a condition to lay eggs. 



So far as the farmer is concerned vegetable feeding insects 

 can be divided into three groups. I. Those insects that 

 live, either in the young or adult stages or both, within the 

 tissues of the plant. These are called borers. They feed 

 upon the juices and tissues inside the plant. II. Those 

 that suck the juices of plants, in which case one finds no 

 parts of the plants eaten away, but the laaves shrivel up and 

 dry or turn another color. These are called sucking insects. 

 They pierce the plant with their mouth-parts and simply 

 suck the juices. III. Those that eat the parts of plants, 

 in which case we find places eaten away, or parts eaten or 

 cut oS, as we say. These are called biting insects. They 

 feed upon at least the outer parts of plants and in most 

 cases the inner tissues at the same time. 



Remedies. — From the nature of the case, it is evident that 

 each of the three groups of insects as above described will 

 require a different mode of treatment. 



In general (special and exceptional cases will be noted 

 under their respective heads) the best if not the only way 

 to get rid of the borers is either to dig them out or, as has 

 lately been successfully done in the case of the peach tree 

 borer, pour hot water on that part of the tree that is infected. 

 The application of chemicals after the insect is once inside 

 the plant is of little or no use, since the plant would be 

 killed before the insect could be reached. The application 

 of chemicals to prevent tlieir entering has succeeded in some 

 cases. Paris green or London purple mixed with water (see 

 formula under insecticides) and thrown in the form of a spray 

 (apparatus for spraying will be explained later) on to the 

 plant or parts of the plant liable to be infected, has resulted 

 in lessening the attack in a number of cases where the in- 

 sect or its young eat their way in through the outer tissue. 



