568 
DIPTERA. 
much smaller and 
locust-tree. During 
inhabiting the 
more common species, 
w the month of August, some of the 
leaves of this tree will be found to have one edge thickened 
in substance and rolled over, so as to form an oblong cavity, 
cylindrical in the middle, and tapering at each end. This is 
the work of the larva) or young Cecidomyians, two or three 
of which will sometimes be found in each cavity, where also 
they complete their transformations. The larva is a maggot 
of a whitish color, faintly tinged with orange, particularly 
towards the head. The pupa or chrysalis is not contained 
within a cocoon. The fly measures three twentieths of an 
inch in .length. It is orange-colored, with dusky antennae 
and wings, three dusky lines on the thorax, and two dusky 
spots on the sides of the body. An apparent interruption 
in one of the veins of the wings, noticed by Professor Hal- 
deman, is not peculiar to this insect, but may be seen, more 
or less distinctly, in our other species of Cecidornyia. 
The Hessian fly was scientifically described by Mr. Say, 
in 1817, under the name of Ceci- 
domyia destructor* (Fig. 257). It 
obtained its common name from a 
supposition that it was brought to 
this country, in some straw, by the 
Hessian troops under the command 
of Sir William Howe in the war 
of the Revolution.! This supposi- 
tion, however, has been thought to 
be erroneous, because the early in- 
quiries made to discover the Hessian 
fly in Germany were unsuccessful ; and, in consequence 
thereof, Sir Joseph Banks, in his report to the British gov- 
ernment, in 1789, stated that “no such insect could be found 
to exist in Germany or any other part of Europe.” J It 
Fig. 257. 
* Journal of the Academy of Natural Sciences of Philadelphia, Vol. I. p. 46. 
t Dobson’s Encyclopaedia, Yol. VIII. p. 491. 
f Encyclopaedia Britannica, and Dobson’s Encyclopaedia, Vol. VIII., Article 
Hessian Fhj. 
