25 
is an important inquiry. It is very probable that the larva can work 
its way to the surface, from a greater depth than what the pupa can. 
Direct experiment only can determine accurately at what depth the 
insect, in both these stages, must be buried in order to destroy it. 
No information of any value can, therefore, be given upon this point, 
until such experiments are made. 
Descriprion or THE CLEAR-WINGED WHEAT-FLY,. 
The importance of full and accurate descriptions of every one 
of the several parts of a natural object, in order that it may be iden- 
tified with certainty, is strikingly illustrated in the present species. 
For some years it has been supposed to be identical with the Eng- 
lish wheat-fly ; but those who are aware of the large number of both 
plants and animals in Europe, that have analogous representatives 
in this country so closely resembling them as to have been in many 
instances for a long time considered identical even by accurate and 
experienced observers, could not but entertain doubts upon this 
point ; and with the fifteen or twentv characters of this insect which 
could be gathered from different sources, I could still only say that 
our wheat-fly was probably the tritici of Mr. Kirby, some of its 
prominent peculiarities seeming even to conflict with the descrip- 
tions given of that species. For instance, all that we could gather 
respecting the form of the joints of the antenne, was, that they 
were “ moniliform” ; and Messrs. Kirby and Spence, in their “ In- 
troduction to Entomology,” define this term to mean “ oval or glo- 
bular joints, like a necklace of beads.” Now the joints of the an- 
tenne in our insect are oblong, and each has a marked contraction 
in its middle, thus approaching to an hourglass shape, a form the 
very reverse of “oval” or “ globular.” It was not until I saw the 
excellent figures and descriptions of Mr. Curtis, that I became well 
assured that our species was identical with the European. 
The common reader will get the most clear and definite idea of 
the appearance of.the wheat-fly, by being told that it looks almost 
exactly like the wheat-worm with wings and legs added to it. These 
members, however, are so very small as to be scarcely recognized 
by the naked eye, except when they are fixed intently upon the 
object. 
The ueap of the female Cecidomyia tritici (Plate 5, fig. 1) is of 
an orbiculate or flattened-globular form, with the eyes forming its 
P 4 
