20 BULLETIN 1487, U. S. DEPARTMENT OF AGRICULTURE 
bird’s nest taken in the field; and the species probably does hibernate 
in various protected places. Females have been successfully carried 
through the winter in an outdoor cage at the laboratory by placing 
them in large glass vials containing crumpled dried leaves. 
The attraction of the brown-tail moth is further manifested by a 
decided preference that seems to be exhibited by ovipositing females 
for brown-tail moth parasites. The species is reared in large numbers 
from the tachinids that attack that host and is much more frequently 
obtained from the hymenopterous parasites of the brown-tail moth 
than from other Hymenoptera. In Europe it also seems to attack 
extensively a tachinid that forms its puparia within the pupae of the 
gipsy moth. The injury caused to Apanteles melanoscelus is almost 
negligible. 
EURYTOMIDAE 
EURYTOMA APPENDIGASTER (SWEDERUS) 
(Fig. 5) 
This European species of Eurytoma has been the most abundant 
of the hyperparasites of Apanteles melanoscelus encountered, although 
not greatly surpassing in importance either Hemiteles tenellus or 
Dibrachys boucheanus. It has been obtained in large numbers from 
practically all of the collections of cocoons made by the writers. 
In the New England States this species has either one or two genera- 
tions annually, two being apparently the more common. The adults 
of the overwintering brood emerge from their host cocoons over a 
period of several weeks during the latter part of May and early June, 
or shortly before the first-generation cocoons of A. melanoscelus can be 
found in the field. A partial generation of Eurytoma develops on 
these cocoons; but apparently a large proportion of the females live 
until the more abundant second-generation cocoons appear, and 
attack these as well. The adults are exceedingly hardy, and doubt- 
less live for a long time in the field; in the laboratory they have been 
kept alive for several months. The first-generation cocoons attacked 
almost invariably produce adults the same season; but a large 
majority of those of the second generation that are parasitized carry 
a Eurytoma over the winter. The species hibernates as a mature 
arva. 
In order to obtain some idea of the number of eggs that may be 
deposited, five females, all of which emerged on May 31, were contin- 
ually supplied with cocoons of Apanteles throughout their life. Three 
of these failed to oviposit even once though cocoons were furnished 
them every day for two months. Of the remaining two, one depos- 
ited 111 eggs over a period from June 18 to September 20, and the other 
laid 163 eggs from June 12 to September 28. Females of this species 
have been observed to feed extensively at the puncture holes made by 
the ovipositor. Very often no oviposition occurs, the punctures 
being apparently made for the sole purpose of feeding. 
Like the majority of hyperparasites, this species is ectoparasitic. 
The egg is deposited inside the cocoon but external to the host larva 
or pupa, and is not attached either to the Apanteles larva or to the 
cocoon. It is unusually striking in appearance because of the minute, 
closely set, blackish spines which cover it, and also because of the 
curious, usually folded, stalk at the posterior end, and the short deli- 
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