REPORT OF THE SECRETARY OF AGRICULTURE. LXXXVII 



insects are more apt in the future than in the past to reach our shores 

 throuo'h importations of fruit trees and ornamental stock. The scale 

 insects of foreign countries are perhaps the most important pests to be 

 consiidered in all ([uarantine and other operations looking to the pro- 

 tection of our growers from foreign invasions, since these insects live 

 for the most part attached to the l)ark of trees and are much more apt 

 to be brought in with plants than are other insects. 



Insects Injurious to Shade Trees. 



Many complaints of insects affecting shade trees have been received 

 in recent years, and among these are several important foreign species, 

 which have been under investigation during the year. 



Insects Injurious to Truck Crops. 



The studies already under way on destructive insects affecting truck 

 crops have been actively followed up, and an extensive report on the 

 principal insects that have recentlv been injurious to vegetable crops 

 has recently been issued. A number of insects injurious to legu- 

 minous food crops received considerable attention, and the new facts 

 discovered in the life histories of some of them are of value in sug- 

 gesting means of control. 



Work on Insects Injurious to Stored Products. 



Certain insects of this class are increasing their ravages. The 

 Mediterranean flour moth, which is the most troublesome of all insects 

 that are harmful in flouring mills, was reported as injurious in mills 

 in new localities in California, and in Michigan, Wisconsin, and Min- 

 nesota. The Angoumois grain moth has also increased in injuriousness 

 in a number of States, particularly northward and in California. 



The cigarette beetle has been very destructive during the past 

 season. Thorough investigations were conducted with a view to find 

 a remedy for this pest, and much of value was learned and published. 



An exotic cabinet beetle did much injury to silk in New Jersey and 

 to domestic tanned leather in New York City, its introduction being 

 traceable to the introduction of foreign hides. In the treatment of 

 the insects which affect stored products, recent experiments with 

 h3'drocyanic-acid gas indicate that this remed}^ nia}^ in course of 

 time, be found more valuable than the bisulphide of carbon usually 

 employed in the treatment of many such insects. 



Work on Insects in their Direct Relation to the Health of Man. 



Insects as conveyers of disease to human beings have been the sub- 

 ject of special research by the Entomologist for the past three years. 

 A popular article on this topic was published in the Yearbook for 



