36 NEW YORK STATE MUSEUM 



ticable to put the poison. Others feed underground on roots and must be 

 fought in special ways. Sucking insects also present exceptional difficulties. 

 Some are cased with so resistant armor that it is nearly impossible to kill 

 them with substances that will not at the same time injure the plant. The 

 attacks of many plant lice cause the leaves to curl so that it is very difficult 

 to hit them with a spray. Small leaf hoppers sometimes occur in such large 

 numbers that, owing to their activity and resistance to insecticides, they are 

 very difficult to control. Others, like biting forms, may work beneath the 

 surface of the soil, and are therefore nearly inaccessible. Study has shown 

 that in the case of almost every injurious insect there is some point in its 

 life history where it is comparatively easy to keep the pest in check. A 

 little difference in cultural methods will sometimes accomplish much. As a 

 general rule, the wholesale destruction of insect life by the use of deadly 

 sprays is to be avoided. Prevention is the most successful method of antici- 

 pating insect depredations. That is, avoid, so far as possible, offering con- 

 ditions favorable for the development of insects in large numbers. .Sup- 

 pression and control, rather than extermination, should be the aim. The 

 latter is impossible, generally speaking, while the former is frequently our 

 only hope. 



Useless remedies. Avoid patent remedial preparations, specially those 

 that are advertised to kill most, if not all insects, and act as a fertilizer in 

 addition. A large corps of trained workers in e.xperiment stations and other 

 public positions are at present engaged in searching for new insecticides 

 and in determining the best methods of applying them. Recommendations 

 from such sources can usually be relied on. Some of the preparations sold 

 in the markets are undoubtedly of value, but they almost invariably owe 

 their efficacy to well known substances and not to secret compounds. 

 The great objection to this class of insecticides is that the consumer pays 

 several times the value of the article, because it is in a disguised form, and 

 he is usually ignorant of its nature. There are other so called remedies 

 which are totally worthless, having no intrinsic value of themselves. One 

 of the most persistently advertised of these is the old trick of plugging a 



