120 PARASITES OF GIPSY AND BROWN-TAIL MOTHS. 



absent in the city. Something of the same sort may be true of the 

 parasites which assist in effecting the control of the gipsy moth in 

 many localities in Europe where it is so uncommon as to make col- 

 lection of material for exportation in any quantity impossible. Some 

 of the most interesting lots of caterpillars or pupae which have been 

 received were from such localities, and it may well be that there are 

 parasites abroad which have not been received at the laboratory in 

 Massachusetts in sufficient quantity for colonization, and which can 

 never be received there until new methods for collecting and import- 

 ing them are devised, but which at the same time are actually among 

 the important species. This fact can only be determined definitely 

 by careful study of the gipsy moth in localities where it was not 

 sufficiently abundant to permit of its collection in large quantities. 

 These studies, it is hoped, will be instituted in 1911, and so long as 

 the gipsy moth continues to be a serious pest in America the inves- 

 tigation of its parasites abroad ought to be continued. 



The ramifications of the parasite work have been so many and so 

 diverse and have led so far afield, both literally and metaphorically 

 speaking, as to make it practically impossible to report upon it as a 

 whole as fully as would be desirable and practicable were it less 

 extensive and varied. A chapter might be written upon the para- 

 sitism of the gipsy moth and another upon that of the brown-tail 

 moth in each of the several countries in Europe from which the 

 parasite material has been imported, but it is wholly impracticable 

 to do so. At the same time, now that a new phase of the work is 

 being entered upon, it will not be out of place to review in some 

 slight detail the results of the work which has been carried on in a 

 few of the localities which, for one reason or another, may be selected 

 as of more than general interest in this immediate connection, but 

 which are at the same time and in another sense typical. 



PARASITISM OF THE GIPSY MOTH IN JAPAN. 



From the viewpoint of gipsy-moth parasitism Japan possesses a 

 peculiar interest, because, if we are to judge from the reports of 

 those who have been there and incidentally or critically studied the 

 situation, the Japanese gipsy moth is pretty thoroughly controlled 

 through natural agencies, and among these its parasites appear to 

 rank very high. This is the more interesting and encouraging 

 because the Japanese race is notably larger and at the same time 

 more fecund than the European, judging from counts as made at the 

 laboratory of the number of eggs in a mass. 



In 1908, after several unsuccessful attempts which had been made 

 to import its parasites had served to domonstrate the futility of any 

 less radical course, Prof. Trevor Kincaid, of the University of Wash- 

 ington, Seattle, was delegated to spend the summer there in the 



