2lL> (iVI'SY AM) BROWN-TAIL MOTHS. [Jan. 



localities where thousands were dead or dying from a disease. Inasmuch 

 ;is the control iif these insects by natural agencies is of greatest im- 

 portance, wo would recommend that careful and extensive studies and 

 experiments lie conducted, with a view of determining whether, under 

 any conditions, those diseases could be made more efficient by artificial 

 means. 



Recommendations and Com-lusions. 



In the first place. \\o wish to place on record our opinion that the 

 condition of the infested territory has been marvelously improved in 

 the last two years, and residents of the Commonwealth as well as those 

 responsible 1'or this condition are to be congratulated thereupon. The 

 progress already made in importing parasites of both the gypsy and 

 brown-tail moths is exceedingly _: ratify ing; and, judging from what we 

 know of other insects which have been imported from foreign lands, 

 free from their natural checks, as is true of the species under consider- 

 ation, we deem i he situation distinctly encouraging. There is a very 

 good pro.-pect of one or more of these natural enemies multiplying 

 enormously, and becoming correspondingly efficient checks on the depre- 

 dations of these two very destructive and annoying leaf feeders. 



Secondly, we would urge most seriously the importance of careful 

 biological studies of the parasites of both the gypsy and the brown-tail 

 moths. It appears upon inquiry that comparatively little is known 

 concerning the habits of any of these species, and, as experience has 

 shown repeatedly, in the case of injurious forms, that apparently insig- 

 nificant factors in the life history may prove to be the vital point in 

 successful control, so in the case of these parasitic forms habits at 

 present unsuspected may possibly be taken advantage of to bring about 

 a most gratifying multiplication and corresponding efficiency so far 

 as suppressing' the gypsy and the brown-tail moths is concerned. These 

 investigations, furthermore, should be conducted on a comprehensive 

 basis, and could hardly be planned to cover a period of less than three 

 to live years, if the best results are to be obtained. A biological study 

 of these forms, in our opinion, should not be confined to this country, 

 as there may be determining factors in Kurope which do not exist in 

 this country, or are not readily apparent hero. Consequently, we would 

 sn-j-er-t that, iii a certain sense at least, parallel biological investigations 

 I' :>li parasites of both the gypsy and the brown-fail moths be under- 

 taken a Ion-' comprehensive linos in both Kurope and America, as no 

 time should be losi in determining the vital points in the habits of the 

 beneficial forms. 



Thirdly, we would emphasize most strongly the advisability of study- 

 ing the apparently rare or inconspicuous natural enemies of both the 

 jypsy and the brown-fail moths, since experience has repeatedly shown 

 that Km-opean species, rarely noticeable 011 account of their depreda- 

 tions in their native country, may become the most destructive p. 

 in another part of the world. Therefore, it would not be surprising if 



