38 Bulletin Wisconsin Natural History Society. [Vol. 10, Nos. 1 & 2. 
the Hessian fly parasite, Semiotellus destructor, figured 
in my Seventh Report, plate 3, fig. 1, which figure will 
also serve to represent this insect in almost every par¬ 
ticular. It pertains to the genus Pteromalus, a name 
derived from two Greek words, meaning bad wings, the 
wings in these insects being nearly destitute of ribs or 
veins. As they, by destroying the parasite of the 
tobacco-worm, cause that worm to be more numerous, 
and hereby more injurious to the tobacco, and as they 
will often occur lurking about this plant in search of 
the cocoons upon which to bestow their eggs, they may 
not inappropriately be named the Tobacco Pteromalus. 
All the flies which came from the cocoons were females, 
from which the following description is drawn: 
* The Tobacco Pteromalus (Pteromalus Tabacum), is 
one-tenth of an inch long- to the end of its body, and is 
of a dark or bottle-green color with a brassy reflection, 
and finely shagreened upon the head and thorax. The 
head is large and placed transversely, about three tim'es 
as broad as it is) long-, convex in front and concave at its 
base, viewed in front it is nearly circular, with a large 
oval eye, slightly protruding on each sid'e, of a dull red 
color fading to brown after death. On the crown three 
ocelli or eyelets appear as glassy dots placed at the corners 
of a triangle. The jaws are yellow, their ends brown, 
with four minute teeth, the palpi or feelers are dull white. 
The antennae are inserted in the middle of th'e face and 
when turned backward reach about half the length of the 
thorax. They become a little thicker towards their tips, 
and are of a brown color, with the long basal joint dull 
pale yellow, and are clothed with a short incumbent beard. 
They are composed apparently of nine joints, th'e first joint 
being long and smooth, and forming an angle with the 
remaining joints. The second is the smallest of the series, 
being but little longer than thick and obconic in its form. 
The third joint is thrice as long and nearly thrice as 
thick as the preceding and has the shape of a pear, the 
contracted portion of its base being formed of two rings 
or small joints which are rartely perceptible even in the 
live specimen when highly magnified, except these organs 
• Beginning page 226. 
