1908.] PUBLIC DOCUMENT No. 73. 217 



much less of a menace to the surrounding country; and, even if abso- 

 lute suppression is impossible, the retardation of the spread of the 

 insect will result in an enormous saving and permit of the development 

 of more perfect means of control, so that the future devastations of 

 the insect may be greatly reduced. 



In conclusion, I beg to express my appreciation of the favors ex- 

 tended by the authorities, and the excellent opportunity offered for 

 the examination of every phase of the work. 



REPORT OF PROF. S. A. FORBES, 



PROFESSOR OP ENTOMOLOGY, UNIVERSITY OF ILLINOIS. 



URBANA, ILL., July 24, 1907. 

 Mr. A. H. KIRKLAND, Superintendent, 6 Beacon Street, Boston, Mass. 



DEAR MR. KIRKLAND : In accordance with your invitation, I had 

 the pleasure of a visit, July 10 and 11, to the laboratory near North 

 Saugus, Mass., of your force engaged in a study of the parasites of 

 the gypsy and brown-tail moths, as an experiment in the method of 

 -controlling those pests. I made a careful examination of the equip- 

 ment, materials and methods of the work there in progress, receiving 

 from Mr. Fiske and the assistants engaged with him every possible 

 aid to a critical study of their operations and to a full knowledge 

 of the results of their work, so far as these have as yet appeared. I 

 examined the parasitized material as it arrives from Europe, following 

 it through the various processes of inspection, assortment, maintenance, 

 protection, experimental multiplication and release, and obtained the 

 records of the season, showing the number of parasitic species obtained 

 from the European collections, and the number of individuals of each 

 species which had been liberated this year for their natural service as 

 parasites of the destructive caterpillars. I also paid particular atten- 

 tion to the methods used for detecting and destroying secondary para- 

 sites of the beneficial species, and of making sure that no European 

 insect other than the parasitic species yon desire to multiply is per- 

 mitted to escape from your importations. 



My notes cover in detail the operations of the laboratory and the 

 methods and results of its various lines of work. These notes were 

 made, however, merely with a view to making sure that I understood 

 the whole scheme of your work; and it does not seem to me worth while 

 to expand them into a description of your methods or a statement of 

 your present results, all of which have appeared, or will eventually 

 appear, in full in your own published reports. It will serve the pur- 

 poses of my visit completely, I am sure, if I give you my opinion of 

 the methods, and make any suggestion which may have occurred to me 

 'looking towards their possible improvement. 



With reference to your plan of operations, the equipment provided 



