29 
color is most observed; but varies from that to amber or honey- 
yellow, lemon-yellow, and even to a cream-color. ‘The specimens 
already spoken of as having been rasied in dried earth, are all quite 
pale ; and it would hence appear as though these lighter colored 
varieties were caused by unfavorable circumstances in which the 
insect had been placed when in its larva state. 
THE SPOTTED-WINGED WHEAT-FLY. 
Another species of Cecidomyia ( Plate 5, fig. 2), as the reader 
has been already informed, is frequently met with, associated with 
the triticd in fields of wheat. It is closely allied to the triticz in form 
and coloring, having like it an orange-red body, hyaline wings, pale 
yellowish-white legs, and twelve joints to the antenne, identical 
with those of the tritici in their details. It is, however, readily dis- 
tinguished from the ¢ritic?, as well as from all the other species of 
this genus, with only two or three exceptions, by having spots upon 
its wings. 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 seven 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. Three others are based upon the inner margin, re- 
spectively at the apex of the medial and anal nervures, and at the 
axilla or base of the anal cell. The seventh 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 thorax is often of a darker 
