84 PARASITES OF GIPSY AND BROWN-TAIL MOTHS. 



ingly the junior author was commissioned to visit France, Italy, and 

 Russia in the winter and early spring of 1911, and subsequently to 

 spend the breeding season- if found desirable, in Japan. He was 

 given authority to employ the necessary agents in each of these coun- 

 tries. He sailed January 5, 1911. 



KNOWN AND RECORDED PARASITES OF THE GIPSY MOTH AND OF 

 THE BROWN-TAIL MOTH. 



When the work of introducing the parasites of the gipsy moth and 

 of the brown-tail moth was begun in 1905, the available assets con- 

 sisted of generous appropriations by the State of Massachusetts and 

 the Federal Government, an abundant faith in the validity of the 

 theory which was to be put to test, and a long bibliographical list 

 of the parasites which were recorded as attacking these insects in 

 Europe and Japan. Of these, the appropriations have withstood 

 most effectively the ordeal of the years which have since "passed. 

 Our faith in the validity of the principle at stake has also stood out 

 wonderfully well, when the numerous trials to which it has been 

 subjected are taken into consideration. It is not too much to say 

 that at the present time it is stronger than ever, notwithstanding 

 that a good many facts have come to light in this period which are 

 more or less flatly in contradiction to the theory of parasite control 

 as generally accepted at the beginning. It has more than once been 

 necessary to modify beliefs and ideas as previously held, in order to 

 make them conform to the actual facts. To take a pertinent exam- 

 ple, it was necessary to place an entirely different value upon the 

 bibliographical list above mentioned than that which was placed upon 

 it when the work was begun, and when the policies of the laboratory 

 were first determined. 



Nearly thirty years ago the present head of the Bureau of Ento- 

 mology undertook the compilation of a card catalogue of references 

 to the host relations of the parasitic Hymenoptera of the world. 

 For more than twenty years the work was continued until some 

 30,000 such references were accumulated. From among them those 

 in which the gipsy moth was mentioned as the host were collected 

 and a list of gipsy-moth parasites was published in Insect Life. 1 

 With the exception of a comparatively few recent additions this list 

 forms the basis of that which follows. That of the parasites which 

 have been recorded as attacking the brown-tail moth is largely from 

 the same source. 



' U. S. Department of Agriculture, Division of Entomolog3', Insect Life, vol. 2, pp. 210-211, 1890. 



