418 ANNUAL REPORT SMITHSONIAN INSTITUTION, 1926 
rio to review the corn borer situation. At Bono, Ohio, on the 29th, 
the visitors saw two of the European parasites of the corn borer 
in action under laboratory conditions, and the unanimous opinion 
was that this exhibition was a revelation of a phase of entomology 
of which they had had but the haziest conception. All were enthu- 
silastic. 
The next day this party went to Chatham, Ontario, and visited 
the corn borer parasite laboratory there. In one cage they saw 
thousands of fertilized females of H'zeristes roborator, and this cage 
was carried to a near-by field in which every stalk was infested by 
the borer. The parasites were liberated in full view of the whole 
party of more than 100 persons. Although it was a cold, raw, windy, 
overcast day, the parasites began at once to search for larvae hidden 
in the stalks and to lay their eggs through the tough epidermis of 
the stalks. This delighted the observers. Some of them, incredulous 
that the parasites could locate the borer from the outside, dissected 
the stalks, only to find that in all cases the parasite had unerringly 
deposited its eggs on the hidden caterpillars. At the conclusion of 
this demonstration one prominent educator, the dean of the school 
of agriculture in a great corn State, is reported to have remarked 
that the demonstration had given him an entirely new conception 
of the significance of economic entomology. 
Three years ago I published a paper entitled “ A Side Line on the 
Importation of Insect Parasites of Injurious Insects from One 
Country to Another” (Proceedings of the National Academy of 
Sciences, June, 1922), in which I called attention to the extraordi- 
nary way in which some of the imported gypsy moth parasites have 
taken to native hosts. One of the most extraordinary of these para- 
sites for its general adaptability is the Tachinid, Compsilura con- 
cinnata. Since its introduction in 1906 it has attacked 92 species of 
native insects, and it has established itself in New England in such 
a way as to act as automatically as any native species. 
Lately a significant thing has occurred which intensifies the value 
of this species, and in fact has a bearing upon all such importations. 
The European satin moth appeared in New England recently. It 
multiplied in a most remarkable way, and there was apparently no 
attack upon it by native Tachinids. But the European Compsilura 
had become acclimated, and at once attacked the new European 
invader. Webber and Schaffner have shown in Bulletin 1363 of 
the U. S. Department of Agriculture, now going through the press, 
that in certain last-stage-larva collections a parasitism of 78 per cent 
by this species has been noticed and that in their aggregate of all 
collections parasitism averages 50 per cent. 
