24 
Theronia fulvescens Brulle. 
A single male of this species issued from a mass of Orgyia cocoons 
on July 24, 1890. It is a species which was originally described from 
Colorado, but which is more or less common in the Eastern States. It 
has not previously been associated with its host, so far as we know. 
Apanteles delicatus n. sp. 1 
The small white cocoons of this species, occurring singly, attached to 
the bark of trees over which Orgyia larvae were crawling, were reason- 
ably abundant in September, 1895, and in the autumn of 180G. This 
species again was greatly hindered in its beneficial work by the abun- 
dance of secondary parasites, so much so that but four specimens of the 
adult have been reared. These specimens hibernated within their 
cocoons and issued in March 
and April, 1896, from cocoons 
collected September 9 and 10, 
1895. From other cocoons col- 
lected at the same time issued 
specimens of Dibrqwhys bouchea- 
tuts and Spilochaleis debilis, A 
number of these cocoons were 
collected and opened December 
1 1, 1896, for the purpose of as- 
certaining whether the parasite 
hibernates within its cocoon as 
larva or as pupa, but all, with a 
single exception, instead of the 
original constructor of the co- 
coon, contained hyperparasites. 
Of these the most abundant was Elasmus atratus, which seems to be a 
very destructive enemy of this species. From two to four of its pupae 
were found in nearly every Apanteles cocoon examined. In one, how- 
ever, were two larva- of Dibrachys boucKeanus, and the single exception 
referred to contained a dead adult of the Apanteles. 
On September 10, 1895, the writer saw a nymph of Podistts spinosus 
trying to penetrate a cocoon of the Apanteles with its beak; but, 
although watched for some minutes, it was unsuccessful, and crawled 
away in search of some easier prey. 
Apanteles hyphantriae Riley. 
This species, which is an extremely common and important parasite 
of Hyphantria cunea, was mentioned in Bulletin Xo. 10 of this division, 
pages 53, 54. It made its appearance early in the season of 188G, and 
attacked only half-grown caterpillars of the web worm. During the 
Pig. 11. 
-A pant' leg cL Meatus: Adult male, with empty 
cocoon below— enlarged (original). 
Described in the appendix, page 55. 
