285 
No. 105.] 
been raised in dried earth; are all quite pale; and it would hence 
appear as though these lighter colored varieties were caused by unfa¬ 
vorable circumstances in which the insect had been placed when in its 
larva state. 
THE SPOTTED WINGED WHEAT-FLY. 
CECIDOMYIA CEREALIS. 
Another species of Cecidomyia (Plate fig. 2,) as the reader has 
been already informed, is frequently met with, associated with the 
Tritici in fields of wheat: It is closely allied to the latter in form 
and coloring, having like it an orange colored body, hyaline wings, 
pale yellowish-white legs, and twelve joints to the antennae, identical 
with those of the Tritici in their details. It is, however, readily 
distinguished from the Tritici , as well as from all the other species of 
this genus, with only two or three exceptions, by having spots upon 
its wings. (Plate, fig. lc.) These spots are so conspicuous as to 
be recognized by the naked eye, even when the insect is flying. 
They are of a pale black or smoky color, and six in number on each 
wing. Two, and these the most conspicuous from being commonly 
of a deeper tint, are placed upon the outer margin ; one being at the 
tip of the submarginal nerve, where it unites with the costal; the 
other, half way between this and the apex of the wing. Both these 
spots reach across the costal cell, and often slightly into the externo- 
medial. Another spot occupies the apex of the wing, at the tip of 
the post-costal nerve. Two others are based upon the inner margin, 
one at the apex of the middle nerve and mostly in the inner middle 
cell, the other occupying the middle of the anal cell, but nowhere 
touching the anal nerve. The sixth spot is upon the disk of the 
wing, mostly in the outer middle cell, and is sometimes confluent 
more or less with one or more of the marginal spots. The nerves, 
when traversing these spots, are of a deeper black color than in other 
parts of their course, as are also the hairs which proceed from them 
into the fringed border of the wing. These spots are formed by a 
pigment in the membrane of the wing, the fine pubescence upon 
the surface being no more dense here than upon the other 
parts. The species under consideration is farther distinguished 
from the Tritici, by invariably having the base of the abdomen, on 
its upper side, of a brown or blackish color. The last joints of the 
