188 PARASITES OF GIPSY AND BROWN-TAIL MOTHS. 
The recovery of Schedius under any conditions at all was con- 
sidered as sufficient to justify the repetition of the rearing work of the 
winter before, and accordingly, using a few individuals secured from 
the field early in the fall, a series of generations has been reared in the 
laboratory until the number now on hand (Jan. 1, 1911) runs into the 
hundreds of thousands. In the spring it is planned to establish one 
or two exceedingly large new colonies, sufficiently far distant from 
any of the others to make the recovery of the parasite elsewhere a 
certain indication that it is able to pass the winter in New England 
and thereby justify the labors which have been expended in its 
behalf. 
THE PARASITES OF THE GIPSY-MOTH CATERPILLARS. 
APPARENTLY UNIMPORTANT HYMENOPTEROUS PARASITES. 
It would be presumption to state without qualification that the 
parasites which are here brought together as unimportant are in 
reality that. It may well be that among them are some which will 
be of sufficient promise to make advisable the trouble and expense 
incident to an attempt to transplant them to America, and which will 
serve to fill in the gap in the sequence which the apparent failure of 
Apanteles fulvipes has left. To determine more definitely their 
relative importance abroad is one of the objects of the work for the 
season of 1911, as at present planned, and something more than is 
known now is certain to be known a year from now unless the plans 
for the season go wrong from the beginning. 
The various species coming in this category are called unimportant 
because they have never been received in imported material in 
numbers sufficient to make colonization in America possible, and only 
upon very rare occasions and in the instance of a few amongst them. 
only, in numbers sufficient to indicate that they were of any impor- 
tance whatever in effecting the control of their host abroad. 
The investigations into the parasites and parasitism of various 
native insects more or less similar in one respect or another to the 
gipsy moth have served to throw considerable light upon the status 
of such parasites as these. It has been shown, in the instance of 
the tussock moth, that a parasite may be entirely absent in localities 
where the host is abundant, or else very rare under such circumstances 
and yet be sufficiently common to effect an appreciable amount of 
control in localities where the host is very rare. It is thus possible 
that some among these species may play a very important rdéle in 
keeping its host, when already reduced to relatively small numbers, 
from increasing sufficiently to become of economic importance, and 
that at the same time they may play no part at all in reducing that 
insect from a state of or approaching noxious abundance to within 
its ordinary limits. 
