INJURIOUS INSECTS. 263 



Yar. a. Axillary spot of the wings wanting.* 

 /S. Tips of taiR' whitish. 



Specimens have beei taken almost weekly, from the middle of 

 June, till the fore part of September, in fields of flowering wheat, 

 among the grass of plats contiguous to dwellings, and upon the 

 windows of houses. I do not doubt but its habits are very similar 

 and perhaps identical wifh those of the tritici, and that in proportion 

 to its numbers it is equally destructive. The investigations of another 

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

 upon this most interesting subject. 



Species resembling the wheat-flies. 



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^ antennae, 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, both in their recent and 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 cha- 

 racter. It is hence that I shall at present venture to name and cha- 

 racterize but two 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 clear-winged wheat-fly that 

 they would be confounded with it by ordinary observers, unless 

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

 species in their perfect state. 



A few specimens occurred to my notice about the middle of the 

 month of August, having the abdomeu more tinged with red than in 



* On a careful rc-examination of all my specimens while copying this paper for the 

 press, and a reference to the dates and situations where each was collected, I discover 

 thai all those which have been gathered from wheat-fields arc of this variety, having 

 but six spots ; and farther that the spot on the inner margin nearest to the base of the 

 wing is situated Mi t/ie middk of the anal cell, thus leaving the space about the apex of 

 the anal nervure perfectly hyaline. Should the particulars here specified prove to be 

 permanent and constant, as I believe iiiey will, it must lead to a separation of this as 

 a distinct species from the caliplera; in which event, the specific name cerealis might 

 appropriately be bestowed upon the real wheat-fly having but sii spots. 



