988 PARASITES OF GIPSY AND BROWN-TAIL MOTHS. 
tail moth imported in hibernating nests, and these methods applied 
equally well to Meteorus. It was not nearly so common as the Apan- 
teles, and only about 1,000 adults were secured for colonization. 
These were all liberated in one colony at a convenient place from 
the laboratory, and in order that they might have an opportunity 
for immediate reproduction a very large number of retarded cater- 
pulars of the brown-tail moth from nests which had been placed in 
cold storage during the winter were liberated upon trees in the 
immediate vicinity. 
These caterpillars seemed to be not at all injured as a result of their 
abnormal experience, but immediately began to feed voraciously and 
to grow apace. That they were injured soon became evident, but it 
could not be determined whether such injury was due to the enforced 
lengthening of their period of hibernation, to the hot weather which 
then prevailed, or, possibly, to the fact that the folage was much 
more advanced than that upon which caterpillars newly emerged from 
hibernation usually fed. They began to die at an alarming rate 
inside of two weeks, and when it was time to make a collection for the 
purpose of determining whether the Meteorus had found them or not 
hardly more than 300 could be found out of the thousands which had 
been liberated. These were removed to a tray in the laboratory, and 
from June 23 to July 15 no less than 76 Meteorus cocoons were 
removed. From these 43 adults, of which 16 were females, were 
reared. 
These were the first females of the second generation which had 
been secured at the laboratory, and a part of them was used in a 
reproduction experiment similar to those which had resulted in the 
production of males the previous year. Curiously enough, the adults 
of the third generation reared from these parents, under circumstances 
identical with those which had been used in earlier reproduction 
experiments, consisted of both sexes, there heing 5 females out of a 
total of 40. These were the first females of the species ever reared 
from adults in confinement. 
In the spring of 1909 the caterpillars from a few nests which had 
been collected the winter before in the vicinity of this first satisfactory 
field colony were fed in the laboratory, and from them a few cocoons 
of Meteorus were secured. It was certain that the species had com- 
pleted the cycle of the seasons in the open, but it was also rather 
evident that it was not very common. If this were due to widespread 
dispersion, as might easily be the case, it might possibly result in the 
species spreading out so thin as to be lost, and it was resolved to place 
the Meteorus reared in 1909 in the same general vicinity, on the theory 
that by spreading over the same territory the colony might be mate- 
rially strengthened throughout. This was done, and about 2,000 
individuals were liberated during that spring and summer, the most 
