216 
PARASITES OF GIPSY AND BROWN-TAIL MOTHS. 
characters in the fall. The space between the pupa or nymph and 
the shell of the puparium is filled by a small quantity of liquid, and 
the complete drying up of this liquid is very prejudical to the health 
of the individual, and is usually sufficient to prevent its emergence. 
The difficulties which have stood in the way of a successful intro- 
duction of BlepJiarijm scutellata into America have differed in many 
respects from those which have accompanied the work with any of 
the other species, saving only the closely allied Crossocosmia. The 
first importations of full-grown caterpillars or freshly-formed pupae 
of the gipsy moth in 1905 resulted in the securing of a considerable 
number of hibernating pup aria. There were several hundred at least, 
but although they were kept under conditions which would be satis- 
factory in the case of most of the tachinids, not a single Blepharipa 
issued in the spring of 1906. The death of the insect did not take 
cent emergence from a total of 5,000 was secured. The year before 
they were also hibernated in earth, but the emergence was less, 
amounting to only 3 per cent of the total, and the year following 
still less, being only about 1 per cent. 
In 1909 for the first time since the inception of the work large num- 
bers of living gipsy-moth pupae containing the immature maggots of 
Blepharipa were received at the laboratory from Hyeres, France, 
through the magnificent efforts of M. Kene Oberthiir, of Rennes, and 
as a direct result of the senior author's trip earlier the same year. 
Some idea of the size of these shipments may be gained by reference 
to Plate XIX, figures 1 and 2, which show a small proportion of the 
toi al number of packages at the time of their receipt at the laboratory. 
For the first time it was possible to allow the formation of the puparia 
under natural conditions in the earth. During each of the preceding 
years the caterpillars and pupse had been received from abroad by 
means of the ordinary methods of transportation and puparia had 
been formed in the boxes on receipt. They were often injured and 
always thoroughly dried. when received. This year provision had 
place until after the fly was 
fully formed and apparently 
nearly ready to issue from the 
puparium. 
Fig. 40.— Blepharipa scutellata: Basal portion of tracheal 
"funnel." Greatly enlarged. (Original.) 
A great many different 
methods of hibernating these 
puparia have been experi- 
mented with at the laboratory 
with variable, and until the 
winter of 1909 with poor, re- 
sults. During the winter of 
1907-8 the puparia were kept 
in moist earth and a 10 per 
