LETTER OF TRANSMITTAL. 



U. S. Department of Agriculture, 



Bureau of Entomology, 



Washington, D. C, April 12, 1911. 

 Sir: I have the honor to transmit herewith the manuscript of a 

 report of progress on the importation into the United States of the 

 parasites of the gipsy moth and the brown-tail moth. To this has 

 been added some consideration of previous and concurrent efforts to 

 handle the parasites of destructive insects in a practical way. The 

 work with the foreign parasites of the gipsy moth and the brown- 

 tail moth has been going on now for rather more than five years. 

 It promises excellent results, and the present seems the proper 

 time to present to the people interested a somewhat detailed account 

 of what has been done and of the present condition of the work. I 

 recommend that this manuscript be published as Bulletin No. 91 

 of this bureau. 



Respectfully, L. O. Howard, 



Entomologist and Chief of Bureau. 

 Hon. James Wilson, 



Secretary of Agriculture. 



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