. 724 TJie recent appearance of the Hessian Fhj. 
As seen under a one-inch object-glass, the eyes and head were 
black, the fore-bodj black, with yellow or pale-brown patches 
below the insertion of the wings, and in front, on the side of the 
body. The abdomen at this date (that is, about eighteen hours 
after first observation) was of a raspberry colour, paler below, and 
above only showing this colour at the divisions of the segments ; 
these were banded across the back with a black or dark tint, and 
on each side of the six segments nearest the fore-body was a 
small black velvety patch ; the two terminal segments of the 
abdomen and the ovipositor were of a pale brown or yellow 
tint. On the second day of examination the red tints were, 
changing to brown ; and on the third day, when the gnat midge 
was quite dead, the tints had deepened further in shades of 
brown. 
The three wing veins were longitudinal (as shown at Fig. 4, 
as the neuration cannot well be conveyed in the smaller figure) ; 
the peculiar form of the third nerve is a cha- 
Fig. 4. — Winrj racteristic of this species. The wings are 
o f the Hessian sprinkled with small scales, and with hairs of 
Fly, showing different form and length, some of which are con- 
its neuration. veyed by the line of dots in the figure of the fly. 
The antennae or horns are distinctly beaded, the 
two lowest joints being broader and shorter than 
the others, and the joint at the tip much longer 
than the preceding. 
I am informed by Mr. R. H. Meade, who at 
my request was good enough to make a micro- 
scopic investigation as to the presence of two 
small lamellae on the ovipositor, that these were absent, which 
is another characteristic of the female of the C. destructor ; and 
after minute watching and examination, with powers from ordi- 
nary magnifiers up to a quarter-inch focus, at intervals during 
more than two days, so as to secure notes of the appearance 
of the insect during its changes of colour up to development 
and immediately after death, and likewise details of points of 
external structure, and comparing these with the authorised 
descriptions given by the leading American and ^German 
Entomologists who have written on the subject, it does not 
appear to me open to doubt that this gnat midge is the true 
Hessian Fly, the Cecidomyia destructor, of Say. 
This matter being one of great agricultural importance, I take 
leave to mention that 1 have been confirmed in this view by the 
valuable opinion of Professor Westwood, Life President of the 
Entomological Society of London ; and that of Professor VV. 
Saunders, President of the Entomological Society of Ontario, 
