FAMILY TIPUUDJE. 179 



Cecidomyia robinia ( Haldeman). ( Plate iv, figs. 3, 4, 5, 6.) 



Color of the fly orange red ; antennas and wings dusky ; thorax marked by three dark 



lines : two dusky spots on the sides of the body. Length three-twentieths of an inch. 



The larva is a maggot of a whitish color, faintly tinged with orange, rather deeper 



towards the head : pupa or chrysalis naked, or destitute of a cocoon. 



This species inhabits the locust-tree, and was first described by Prof. Haldeman*. The 



leaf becomes thickened on its edge, and rolled over ; and thus a cavity is formed, which 



contains two or three larvae of this species. 



Cecidomyia salicis ( Fitch). Willmo Cecidomyia-f, 

 Color of the fly black above, paler beneath and downy ; wings smoky ; legs gray. Length 

 of the body, one-fifth of an inch ; expansion of wing, three-tenths. 

 Inhabits a reddish gall upon the low willow bushes of wet places : it is of an oval form, 

 three-fourths of an inch long, and is terminated by a conical beak. Within a silken lined 

 cavity, early in the spring, there will be found a single orange-colored maggot one-fifth of 

 an inch long. Soon it changes to a pupa, but without moulting ; and in a very few days it 

 passes from its prison, after casting the pupa skin, and takes the winged form. Its size, 

 together with the rapidity of its changes, renders the species an interesting object of study. 

 Its damage to the basket willow is but slight. 



Cecidomyia culmicola ( Morris). 



The C*. culmicola is a provisional species, whose habits have been investigated by Miss 

 Margaretta H. Morris, by whom also it was discovered. Its habits are quite diflerent 

 from those of either of the foregoing species. The fly lays its eggs upon the grain, in or 

 over the germ, where they remain unhatched until the grain germinates ; but when the 

 plant is three or four inches high, the worm may be seen, by the aid of a glass, feeding 

 above the top of the joint in the centre of the culm, imtil it is ready to become a perfect 

 insect. It is said that the pupa resembles that of the C. destructor. 



As the fly deposits its eggs early in June, it is difiicult to understand why they should 

 remain unhatched so long, or until the future germination of the same ripened grain after 

 it is sown, and then to feed upon the culm ; for it is the usual habit of flies to deposit their 

 eggs near or upon the magazine of food on which the larvse are to subsist. 



It is an interesting fact that most, if not all of the species of Cecidomyia are preyed upon 

 by some one or other of the family of Ichneumonides while in the larva or pupa state. 

 These parasites deposit their eggs within the body of their victim, where they are hatched 

 in due time, and the larvae subsist upon and destroy the body before its change into the 



• American Joarnal of Agriculture and Science, Vol. vi, p. 193. f Mem, Vol. 1, p. 283. 



