67 
looper as its favorite host in this country. In Europe this chalcis 
fly is also particularly attached to the genus Plusia, although known 
to parasitize larvae of several other genera of Noctuidae as well as 
other families. The habits of this parasite were described by Dr. 
Howard in the American Naturalist for February, 1882 (pp. 150, 
151). An interesting instance of its value as a destroyer of the looper 
is cited in the annual report of this Department for 1882 (1883, p. 121). 
In the fall of 1880 nearly fifty larvae were collected, with the intention 
of rearing the moths, but all, with a single exception, were eventually 
destroyed )rv this parasite, only 2 per cent of the larva? having reached 
the imago state. As parasitized loopers approach full growth the} T 
lose their characteristic pale longitudinal stripes and become uniform 
pale green or yellow in color. As a rule, in the writer's experience, the 
larva? spin up before succumbing, and in a few days parasitism by this 
chalcis fl} T is clearly evident, since the pupa? do not develop and the larvae 
assume a peculiar twisted form. Almost without exception the bodies 
of the parasitized larva? are complete^ filled with these almost micro- 
scopic parasites. By actual count 2,528 chalcis flies issued from a 
single parasitized larva. In recent experience the parasitic flies have 
been reared only from their host during the last week of September 
and in October. 
Apanteles congregatus Say, a well-known parasite of the imported 
cabbage worm {Pieris rapse) and other noxious species has been reared 
from this looper. 
It has been noticed on several occasions that when the larva of the 
looper forms its characteristic gauzy white cocoon on other plants than 
those on which larva? have fed, the individual is usually diseased or par- 
asitized. Thus, on one occasion the writer took five chrysalides from 
eggplant, although no evidence whatever could be found that the larvae 
had fed on this plant. Larva? were found on eggplant, but not feed- 
ing, and all of these, although kept in the best of condition, died of 
disease or were parasitized by the Copidosoma truncatella. It may be 
interesting to note of this parasite that the adults issued in late Sep- 
tember, sixteen days after their detection in the body of the host. At 
Brookland, D. C, on one occasion all of the pupa? that could be col- 
lected were parasitized, an evident case of complete parasitism. 
PREDACEOUS ENEMIES. 
A medium-sized white-spotted black spider, PhidJppusaudaxHentz., 
was observed by the writer July 13, destroying the moth of this insect. 
This spider appears to be specially adapted to prey upon Plusia, since 
the web spun by it looks almost precisely like that of the looper. 
Other species of spiders crawl into the empty cocoons of the moth, and 
it seems probable that they feed on the larva? also when these are just 
about to transform. 
