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 his mission and asked the members 

 of the society to assist in the work. The most remarkable response to 

 this request came from Mr. Rene 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 this 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, 1906, 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 of the European range of the 

 brown-tail moth, from Transylvania on the southeast to Brittany 



