20 
Amorphota orgyiae n. sp. 1 
The interesting little Ichneumon flies allied to the genus Campoplex 
(Campoplegini) are general and widespread parasites of lepidopterous 
larvae. They have been seldom reared in the United States, although 
something over twenty species of the old genus Campoplex are known 
to occur in this country. Those which have been reared have come 
from larva' of Noctuidse or Bombycidse, while in Europe they are known 
to attack the larvae of these two families as well as many species of 
Geoinetrida*. Two species of 
Orgyia in Europe are attacked 
by them, viz, Orgyia gono- 
8tigma by Campoplex carbo- 
nari us and 0. antiqua by C. 
mgripesr. 
The species under con- 
sideration lays its eggs in the 
half-grown caterpillars of 0. 
leucostigma. Probably but a 
single e<xg is laid in each cater- 
pillar, siuce but a single larva 
of the Amorphota is found to 
issue. It was noticed that in 
August, 18i)5, a number of 
the hall-grown larva' had been 
parasitized by this species. 
The development of the para- 
sitic larva was undoubtedly 
rapid, although no definite 
observations were made which 
would determine its length. 
CTpon reaching full growth the parasitic larva invariably leaves the 
Orgyia caterpillar, usually issuing from a large hole on the underside 
of the body behind the thoracic segments, and beginning immediately 
to spin at its posterior extremity a stoutish white cocoon marked near 
each end by a ring of large irregular brown blotches. The color of 
these blotches varies in intensity from a light yellow brown to a dark 
mahogany brown, and their size, and particularly their shape, is also 
variable. In addition to these bands there are smaller irregular 
blotches at either end of the cocoon. This cocoon is attached by its 
side to the leaf or bark upon which the caterpillar happens to have 
been crawling. This attachment is not especially firm, and the parasitic 
larva apparently makes no special effort to attach it, and it probably 
adheres simply through the viscidity of the silk when first spun. The 
cocoon is, however, frequently somewhat flattened on the side. In 
general it is subcylindrical in shape, with rounded ends, its average 
length being 6 mm. and its diameter 2.3 mm. 
1 This, with the other new species, will be described in an appendix. (See page 53.) 
Fiq. 7. —Amorphota orgyice: Adult female above, with its 
cocoon and shrivelled skill of the caterpillar host be- 
low— enlarged (original). 
