PARASITES OF LARGER BROWN-TAIL CATERPILLARS. 295 
than the brown-tail moth, and its rate of multiplication, being un- 
questionably more rapid than that of the brown-tail moth, ought not 
to be checked until it has become a factor in the control of its own 
particular host. 
It may be added as a postscript that a few days after writing the 
above a few hundred caterpillars of the brown-tail moth collected in 
the field from hibernating nests were dissected in the laboratory. In 
them were found several of the characteristic first-stage Zygobothria 
larvee (fig. 63, p. 264) embedded in the walls of the gullet. The evi- 
dence presented by this small number of dissections is less satisfactory 
than though the number were larger, but if it is to be accepted the 
rate of increase of Zygobothria in 1910 is considerably better than was 
expected. 
PARASITES ATTACKING THE LARGER CATERPILLARS OF THE 
BROWN-TAIL MOTH. 
HYMENOPTEROUS PARASITES. 
In Europe after the caterpillars of the brown-tail moth resume 
activity in the spring they become subject to attack by a variety of 
tachinid parasites, but so far as has been determined by rearing work 
with imported material the only hymenopterous parasite of any con- 
sequence is Meteorus, which passes the winter as a first-stage larva in 
the hibernating caterpillars. 
In fact, only a single other parasite has ever been reared from 
imported caterpillars which may not have come from some other acci- 
dentally included host, and this is the Limnerium disparis, which has 
already received attention as a minor parasite of the gipsy moth. It 
would certainly seem as though there were likely to be others attack- 
ing the caterpillars of the brown-tail moth in Europe in spite of the 
fact that none has been secured, and this supposition is upheld by the 
published results of a study in the parasites of the brown-tail moth 
which was made a few years ago by a Russian entomologist, Mr. T. W. 
Emelyanoff. He mentions a number of parasites which have not been 
reared at the laboratory from imported material, and among them one, 
Apanteles vitripennis Hal., which is so common, according to his ac- 
count, that the ‘‘cocoons are sometimes accumulated together in great 
numbers.’ Any suspicions that the Apanteles thus observed by him 
is identical with A. lacteicolor Vier, as reared at the laboratory and 
which is the only representative of the genus that has been reared 
from caterpillars collected in Russia or elsewhere, is at once dispelled 
by his detailed account of the early life and habits of the species which 
he had under observation and which differ in all essential par- 
ticulars from the life and habits of A. lacteicolor. The caterpillars 
are attacked soon after they leave the nests. Instead of dying in 
. 
