944 PARASITES OF GIPSY AND BROWN-TAIL MOTHS. 
enough, yellow in the case of the Japanese, and black in that of the 
European species. Between three and four weeks of ordinary 
summer weather are necessary for the complete life cycle. 
The adults are very long lived, and a few of both species were kept 
in confinement from early in August, 1910, until December of the 
same year. During this time they were offered numerous sorts of 
pupee, but after it was no longer possible to secure those of the gipsy 
moth there was no further reproduction. It has always been supposed 
that it was the adults which hibernated, and the longevity of the 
individuals mentioned above lends strength to this supposition. If 
Fic. 51.—M onodontomerus zreus: Adult female. Greatly enlarged. (Original.) 
correct, there need be only a single generation annually, and the 
species would therefore be independent of any other host. Neither 
is known to attack the brown-tail moth, but both have been reared 
through their transformations upon pupe of the white-marked 
tussock moth. 
Both of the species of Chalcis are of considerable importance as 
parasites of the gipsy-moth pupe in their respective habits, and so 
far there has nothing occurred to destroy confidence in their ability to 
become of importance here provided a sufficiently large number may 
be secured to enable them to become established. It is confidently 
expected that they will disperse at a very rapid rate, and on this 
account it will be necessary that the colonies be large and strong, so 
that extinction through too great scarcity during the first or second 
season following colonization will not result. Renewed efforts to 
make this possible will be made this coming season, and at the same 
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