398 ANNUAL REPORT OF THE Off. Doc. 



gist, I should discuss the fundamental principles of the greatest 

 subject with which I have to deal, and that will take us directly, of 

 course, to the subject of Economic Entomology, or the application 

 of insect remedies. 



As 3'ou know, we are issuing from the Agricultural Department, 

 bulletins discussing the insects of each respective month and the 

 remedies known for them, because that is the important subject in 

 agriculture and horticulture to-day. We have also issued another 

 circular, entitled "The Birds Around the Farm." These are entirely 

 free of charge and will be sent to persons who write for them or re- 

 turn these postal cards. (Holding up cards). If the June numbei 

 did not reach their destination it is because we are changing our 

 mailing list now; but after this it will be sent regularly the first 

 of every month to the persons whose names we have. We are not 

 spreading them broadcast, however. They will be put into the 

 hands of only those persons who signify their desire to receive them. 

 This is an undertaking on my part, with the permission of Secretary 

 Critchfield, that means much work, but we are gratified with the 

 heart}^ responses we are already receiving from the people. 



I can do little more to-day than to speak to you of the things of 

 which I have already written, for we cannot be successful until we 

 understand the underlying principles of insect warfare. I have sent 

 for a spraying apparatus in order that I could illustrate in a prac- 

 tical manner some of these things. There is just a word of explana- 

 tion concerning this: If I should show you an apparatus, it is not 

 that I am advertising this machine, at all. This is the apparatus 

 that will best suit my purposes and the company gratuitously sent it 

 to me upon the condition that I place their catalogues in this room, 

 and that I have already done. That is all the advertising I am going 

 to give. 



In the first place, we know that the insects that attack our crops 

 are divided into two classes: First, the suctorial insects, or those 

 that feed by sucking the juices from the organisms on which they 

 live, as do the squash bugs, scale insects, plant lice, etc.; the other 

 class is the chewing insects, that chew the tissues of the plants as 

 do the beetles, cut worms, army worms, corn worms, cabbage worms, 

 etc. Now, as a consequence, insecticides are divided into two 

 classes: Those intended to kill by contact (consequently those that 

 must be used for suctorial insects); and secondly, stomach poisons, 

 or those that are intended to be for the chewing insects. You can 

 readily see that if the plants were covered with Paris green or any 

 other poison, a suctorial insect would not be affected, because its 

 bill would be inserted into the plant, and it, therefore, would not 

 get the ])oison api)lied on the surface. These insects must be al- 

 tacked with the contact poisons which kill every thing with which 



