54 PABASITES OF GIPSY AND BROWN-TAIL MOTHS. 



recommended the importance of the introduction of the Japanese 

 parasites, and Dr. Felt suggested the importance of careful biolog- 

 ical studies of the parasites, not only in America but in Europe. All 

 of these suggestions coincided with plans already made which were 

 about to be entered upon, as indicated in following pages. 



The subject of the study of the diseases of the caterpillars does not 

 come under the range of the present bulletin, but since it has been 

 mentioned, it should be stated that the State superintendent has for 

 the past two years been having this subject investigated and that it 

 is now going on under the expert supervision of Dr. Koland Thaxter, 

 of Harvard University, and Dr. Theobald Smith, of the Harvard 

 Medical School. 



Mr. Kirkland's summary seems fully justified. It is as follows: 



It will be seen from the foregoing that the work of importing parasites of the gipsy 

 and brown-tail moths in Massachusetts has been thoroughly examined by practically 

 a congress of the world's leading entomological experts. And it is believed that their 

 consensus of opinion, which is, in the main, that everything possible to secure the 

 successful importation of these insects is being done, will be taken as authoritative 

 and final. It would seem that the last word has been said on this matter, and that 

 there should be no further occasion for that kind of adverse criticism, whose sole 

 effect is to harass those who are giving their best thought and most sincere effort to the 

 accomplishment of the desired result. Destructive criticism of scientific work, by 

 the amateur or dilettante, is absolutely valueless. Constructive criticism, such as 

 these reports make on certain minor details of this important work, is helpful and a 

 public good. 



NARRATIVE OF THE PROGRESS OF THE WORK. 



Down to the time when this work was begun, all attempts at the 

 international handling of beneficial insects had been done either by 

 correspondence or by the sending of an individual collector to search 

 for such insects and to forward them by mail or express or to bring 

 them back himself in comparatively small numbers, the beneficial 

 species being either at once liberated in the field or reared for a time 

 in confinement and then liberated. In planning the present work 

 the normal geographic ranges of both the gipsy moth and the brown- 

 tail moth were well known and most of their parasites had been listed, 

 so that the problem seemed to be a comparatively simple one. Owing 

 to the fact that the most abundant of the Japanese gipsy moths (four 

 of them are listed) presents rather marked differences from the Euro- 

 pean and New England form — so much so, in fact, as almost to justify 

 the opinion that it is a distinct species — and as the ancestors of the 

 New England gipsy moth came from Europe, it was decided to con- 

 centrate the effort, for a time at least and in the main, upon Euro- 

 pean parasites and natural enemies. From the outset the idea was 

 to secure as many parasites belonging to as many different species as 

 possible from all parts of Europe, in the hope of establishing in New 

 England approximately the natural environment of the gipsy moth 



