EEPORT OF THE ENTOMOLOGIST. 197 



of I^ahis ferd, a long narrow ash-gray bug, slightly over a quarter of an 

 inch in length, which is common on wheat and grass.* 



The color of this ijisect is jet Ijlack, with the exception that the anterior 

 tarsi and tips of tibiae are hght-brown, while- the posterior and middle 

 tarsi are darker. The average length seems to be about 1.3™™ (.04 inch). 

 In this respect (Fitch gives the length as .05 inch) and in the color of the 

 tarsi alone do the specimens bred from, the clover -midge differ from those 

 described by Fitch. 



The " mistaken parasite " has not been bred as yet from the Washing- 

 ton specimens. 



THE CLOVEE-LEAF MIDGE. 



{Cecidomyia Trifolii, Low.) 



Order Dipteea, family Gecidomyidae. 



Living within the folded leaf of white clover, from one to twenty minute white to 

 orange colored, footless gruba ; transforming within the leaf. 



Mr. Lintner little thought -when he changed his name of trifolii to 

 legumenicola, on account of its X)reoccupation by Lciw's Eurojiean species 

 that the true trifolii would so soon turn up in America. Yet such has 

 been the case. A Cecidomyia has been studied the past summer at 

 this department, which corresponds so exactly with trifolii that it would 

 be presumptuous for one not an experienced dipterologist to found a 

 new species for it. 



About the middle of June last the leaves of white clover {Trifolium 

 repens) were observed in many instances to be infested by the larvae of some 

 Cecidomyia. The invested leaves, or more properly speaking, leaflets, 

 were each folded together uj)on the midrib, so that the upper side would 

 be inclosed, and so that the two edges of the leaflet would almost ex- 

 actly coincide. The underside of such leaves had a sickly appearance, 

 having turned yellowish or brownish. The fold each side of the midrib 

 was bulged out and gave the leaf a blistered look. 



Such leaves, upon being opened, were found each to contain from one 

 to twenty whitish or pale orange maggots, resembling much the larvae 

 of the clover-seed midge, but being somewhat smaller. The younger 

 maggots were nearly white, while the older ones were of a decided 

 orange hue. The average length of the full-grown larvae in 1.5°™ 

 (.059 inch). The head is very retractile, and 13 segments of the body 

 are plainly observable. The spiracles are each at the summit of a small 

 tubercle, and are placed as in C. legumenicola. The whole surface of the 

 body is very coarsely granulated. 



Some of the folds were, at the time of their discovery (June 18), already 

 empty, others contained larvae and others pupae, the latter inclosed in 

 delicate' white oval cocoons, fastened to the sides of the leaf. 



The cocoons of this species have an important bearing upon the vexed 

 question of the formation of the cecidomyious cocoon. What it may be 

 with others we are not prepared to say, but with G. trifolii it is evi- 

 dently composed of delicate silk.t Another season it is hoped wiU 

 enable us to watch its formation. 



* Trans. N. Y. State Aj;-. Soc, 1860, pp. 818-821. 



tWinnertz, as quoted by Osten Sacken (Dipteraof N. A., vol. I, p. 184), "positively 

 denies that the lai"\ae spin this cocoon ; according to his observation, the latter is, so 

 to say, exuded by the larva. He found that larvae which had fastened themselves to 

 a lea:^ were encircled within twenty-four hours by a white halo, consisting of tiny 



