KNOWN AND RECORDED PARASITES. 93 
NATIVE (AMERICAN) TACHINIDS REARED FROM EUPROCTIS CHRYSORKHEA L., AT THE 
Gipsy Motu Parasite LABORATORY. 
Blepharipeza leucophrys Wied. ? Phorocera leucanixz Coq. 
Euphorocera claripennis Macq. Sturmia discalis Coq. 
Exorista griseomicans V. de Wulp. Tachina mella Walk. 
N. B.—The above species have only been reared very occasionally. The species, however, doubtfully 
referred to Phorocera leucaniz Coq. has been reared through to the pupal stage in considerable numbers. 
These pup have always been imperfect and ‘‘larviform” and at the time of writing none has been reared 
through to the adult. 
The compilation of the catalogue of parasites was originally under- 
taken in the expectation that it would prove of great service upon 
exactly such occasions as the present, when the application of the 
theory of control by parasites should be put to the test. Its value 
naturally depended upon the accuracy of the original records, and it 
was only right to suppose that in the majority of instances these 
could be depended upon. It was equally natural to suppose that 
the parasitic fauna of such common, conspicuous, and widely dis- 
tributed insects as the gipsy moth and the brown-tail moth would 
be well represented in these lists, which were based upon a thorough 
overhauling of European literature, and it was not expected that any 
parasites of particular importance would be found which were not 
thus recorded, unless, indeed, they were confined to Continental Asia 
or to Japan. 
In the fall of 1907, as soon as the turmoil of his first summer’s 
work permitted, the junior author attempted to make use of the 
numerous bibliographical references for the purpose of learning as 
much as possible of the insects with which he was to deal. One 
after another, various species were taken up, until he was in possession 
of practically all of the published information concerning perhaps 
half of the Hymenoptera listed. Then he stopped, because the 
information thus gained was obviously not worth the labor. It was 
not so much that recorded information was scanty, or lacking in 
interest, but it was because in a great many instances it was contra- 
dictory to the results of the actual rearing work which had been 
carried on in the laboratory throughout the summer. It was obviously 
impossible to accept everything at its face value, and apparently 
next to impossible to choose between the true and the false. But 
one thing remained to be done, and that was to determine at first 
hand everything which it was necessary to know concerning the 
numerous species of parasites which it was desired to introduce into 
America. 
If the list of parasites which have been reared at the laboratory 
from imported eggs, caterpillars, and pupex of the gipsy moth and 
the brown-tail moth be compared with the lists which have already 
been given, the numerous and obvious differences which are immedi- 
ately apparent will serve better than words to illustrate the situation 
which confronted us at the close of the season of 1907. 
