60 
PARASITES OF GIPSY AND BROWN-TAIL MOTHS. 
arrangements were made with Miss Ruhl, Mr. Schopfer, Prof. A. J. 
Cook, who was then in Berlin, and several volunteer collectors to send 
in numbers of the winter nests. During his visit to Paris in July, the 
chief of the bureau had addressed a meeting of the Entomological 
Society of France on the subject of Ins mission and asked the members 
of the society to assist in the work. The most remarkable response to 
this request came from Mr. Eene Oberthur, of Rennes, who, although 
not present at the meeting, read the account in the bulletin of the 
society, and placed himself and his services entirely at the disposal 
of the United States authorities. During the autumn of 1905 and 
the winter of 1905-6 he sent to Boston more than 10,000 winter 
nests of the brown-tail moth. In all, 117,000 nests were received 
and cared for during that winter. 
In the autumn the laboratory house (PI. II, fig. 1, p. 56) at North 
Saugus was taken possession of by Mr. Kirkland, fitted up as pre- 
viously described, and occupied by Mr. Mosher; the parasite material 
from Maiden was brought over and installed, and arrangements were 
made for the receipt of the brown-tail winter nests. Very many 
large boxes were constructed, somewhat on the plan of the Cali- 
fornia parasite-rearing cage, each one large enough to contain from 500 
to 1 ,000 nests of the brown-tail moth, the front being pierced with 
auger holes in which were inserted round-bottom glass tubes into 
which the emerging parasites would come in search of light and 
through which they might be examined to differentiate between the 
primaries and the hyperparasites. Much carpenter work was done 
during the autumn and winter months and on into the spring. 
Double windows and double doors were provided, and every crack 
in the laboratory rooms was sealed. Realizing that many different 
kinds of insects might emerge from tins large supply of silken nests, 
including possibly species injurious to agriculture not previously 
introduced into the United States, as well as dangerous parasites of 
beneficial insects, every possible effort was made to prevent the escape 
of any insect whatever from the laboratory rooms. 
On account of the importance of a speedy detection of injurious 
forms coming from these rearing cages, and on account of the 
necessity for the most expert supervision of the laboratory end of the 
experiment, Mr. E. S. G. Titus, an especially well trained expert 
from the Bureau of Entomology, was assigned in the spring of 1906 
to the charge of the laboratory end of the introduction. 
In March, 1 900, Mr. Titus, with the chief of the bureau and with 
Mr. Kirkland and Mr. Mosher, visited the parasite laboratory, and 
for the first time examined the contents of the imported nests. 
There were in the different cages, well separated as to localities, 
winter nests from almost the whole <>f the European range of the 
brown-tail moth, from Transylvania on the southeast to Brittany 
