No. 105.] 287 



and perhaps identical with those of the Tritici, and that in proportion 

 to its numbers it is equally destructive. The investigations of ano- 

 ther year, may, I hope, enable me to furnish something more definite 

 upon this most interesting subject. 



SPECIES RESEMBLING THE WHEAT-FLIES. 

 CECIDOMYIA CALIFTERA: C. THORACICA: C. TERGATA. 



We have what appear to be several species of Cecidomyides, allied 

 to our wheat-flies in size, in the number and form of the joints of 

 the antennse, and more or less in the colors of their bodies. Among 

 objects so exceedingly minute, and so closely related to each other, 

 a most patient and critical study of a large collection of specimens, 

 in their recent as well as their dried state, is indispensable, in order 

 to trace out with accuracy and define with precision each of these 

 species. Perplexity and confusion will be the inevitable result of a 

 hasty or superficial performance of a work of this character. It is 

 hence that I shall at present venture to name and characterize but 

 three of these species, whose marks are so evident and distinct as 

 to render their recognition comparatively easy, yet whose colors are 

 so analogous to those of the two insects above described that they 

 would be confounded with them by ordinary observers, unless aware 

 of their distinctive marks. I am only acquainted with these species 

 in their perfect state. 



From the middle of July to the first of September, a number of 

 specimens were taken, of a species intimately allied to the spotted- 

 winged wheat-fly. The body, however, is more deeply colored, 

 being to a greater or less degree tinged with red, and the thorax 

 both above and on the sides is of a fulvous-brown shade. It may be 

 readily distinguished from the cerealis by its tarsi, the tips of which 

 are of the same pale yellowish hue as the legs, and yet more readily 

 by the spots on its wings, which are seven in number (Plate, fig. 

 I). These spots are similarly placed with those of the wheat-fly, 

 except on the inner margin of the wing, where the present species 

 has three in number. One of these is situated on the apex of the 

 middle nerve, a second one on the apex of the anal nerve, and a 

 third at the axilla or base of the anal cell. These spots, though 

 smaller, are equally conspicuous with those of the cerealis^ being 

 commonly of a deeper shade than those possess which are based oa 



