1909.] PUBLIC DOCUMENT — No. 73. 57 



In conclusion, the present situation may be briefly stated 

 tbus : The fungous disease of the brown-tail moth is undoubtedly 

 the most efficient factor at present working in nature against 

 the ravages of this pest, and under favorable conditions may 

 almost completely eliminate it from considerable areas in a 

 single season. In \-iew of this fact, notwithstanding the un- 

 satisfactory results of the experiments made dui'ing the past 

 year, a continuance of the work for another season seems de- 

 cidedly desirable, for the reason that a second attempt in this 

 direction is not likely to be hampered, as in the firat instance, 

 either by lack of material for early infection, or by such delays 

 in beginning the work as were incident to the firet attempt; 

 while, if the season proves neither unusually early nor unusually 

 dry. much more favorable results may be anticipated. 



The Pahasite Work. 



The work of importing and colonizing the various foreign 

 insects parasitic or predatory upon the gypsy and brown-tail 

 moths has been continued throughout the year. The material 

 imported, while in actual amount not greatly in excess of that 

 of the previous years since the work was begun, has generally 

 been received in better condition and has been more diverse in 

 character. The actual number of beneficial insects liberated 

 was far in excess of that for 1906 or 1907, and the list includes 

 several of great importance and promise which have never be- 

 fore been received at the laboratory in a living condition, or 

 at aU. 



This increase is due to several causes. The improved con- 

 dition of the foreign material on receipt and its greater diversity 

 in character are in part responsible. The laboratory at Melrose 

 Highlands is much better adapted for the work than was that 

 at Saugus; the permanent force at the laboratory has been 

 notably increased ; and, more than all, a larger knowledge of the 

 parasites and predators themselves, their habits and require- 

 ments, has made possible a much more intelligent handling of 

 the imported material. 



Mr. W. F. Fiske, who assumed charge of the laboratory work 

 in 1907. has continued in that position throughout the year, and 

 has been most ablv assisted in the actual work of colonization and 



