DAPARTMENT OF AGRICULTURE, 



Bureau of Entomology, 



Washington, Dec. 8, 1884. 



Sir: This Catalogue of the Entomological Exhibit of the Department 

 of Agriculture for the Woi'ld's Industrial and Cotton Centennial Exposi- 

 tion at Xew Orleans has been prepared, upon your approval, with the 

 object of increasing the general usefulness of the exhibit. In its prepa- 

 ration the aim has been to add such information as the specimens or 

 articles themselves do not convey. 



The collection is made up of the following sections : 



1. IXSECTS IXJURIOUS TO AGRICULTURE, 



Arranged according to the particular plant and the particular part of 

 the plant affected, and containing, as far as possible, the different states 

 of growth of the insect, its enemies and parasites, a statement of the 

 remedies or preventives available and a reference to the chief articles 

 where full information can be found upon it. These references are, 

 principally, to Government and State reports, to which the farmer will be 

 most likely to have access. To this section of the exhibit I have added 

 much material from my private collection whenever the material from 

 the Department collection was insufficient, and a few specimens have also 

 been added by ]\Ir. Sam'l Hexsiiaw, of Boston, whose aid in the prepa- 

 ration of the exhibit and of the catalogue I take pleasure in here 

 acknowledging. The catalogue of eight cases of insects injurious to 

 forest trees is omitted for the reason that the collection did not arrive in 

 time from Edinburgh, where I exhibited it last summer. 



2. Insecticide Substances. 



In the catalogue of this collection the aim has been to add, as briefly 

 as possible, a statement of the method of using such substances, so that 

 whenever in the first section a particular substance is recommended for a 

 particular insect, the reader can t'jrn to this second section for farther 

 details. 



3. Insecticidi: Machinery and Contrivances for destroying 



Insects. 



In the catalogue of this section there is also added such information as 

 will add to the instructive value of the exhibit, and it will be noted that 



