793 



Recnred from tliera in considerable numbers. On October 13 the confiiiod lar\ie 

 were noted as changing rapidly to pupas and a lew days later were all in this stage 

 of develojunent. The pupa- were fcniued occasionally in the mines, but most grubs 

 made their way out before pui)ating, and in continement underwent the change 

 between leaves which lay in contact. In the field it is probald*; Ihat most of them 

 changti among rubbish on the ground under the plants. The i>upa; were observed 

 until October 22. 



The first adult flies came forth indoors Oct(djer 23, and others continued to emerge 

 until November 4, at which date the last Hies were obtained. An examination of 

 infested plants out of doors showed the Hies to be emerging there also, and we must 

 consequently consider this the normal habit of the species. From the lateness at 

 which the adults api>ear it is altogether probable that the winter is passed in this 

 condition. * * * 



The species is very badly afl'ected by a very small four-winged parasitic lly (a 

 new species of Polycystus according to L. O. Howard), which emerges from the 

 ])ui)a;. These began to emerge from our confined lot of pu}>a> later than the Druno- 

 phila and continued to come out at intervals during a considerable jiart of the 

 winter. The first obtained came forth October 30 and the last .January 26, 18y2. 



Larva. — The grub which produces the mine measures when grown aliout 5"'"' 

 (0.2 inch) in length, and 1'"'" (0.04 inch) in diameter. It is whitish, cylindrical, and 

 wrinkled, and tapers slightly toward the head, but terminates rather bluntly behind. 

 The head segment is small, turns downward, and bears the mouth-opening beneath. 

 From the latter project the tips of the tAvo black hooks common to larvie of tliis and 

 related genera. The hooks of this species appear more than usually curved and 

 each beai's several strong denticles. At the hind extremity of the body are several 

 fleshy tubercles and a pair of straight protractile spines, which arise from conical 

 prominences. Just in front of the tip of the body is a pair of transversely length- 

 ened sucker-like structures. 



Pupa. — The pupa is inclosed in a tough and rather firm reddish brown (fulvous) 

 envelope. The latter resembles in no slight degree the "flaxseed" of the Hessian 

 fly. It is fusiform in general shape, but is rather sciuarely cut off in front, an angle 

 at each side being formed by the digitate respiratory prominence. The wh(de 

 anterior part of the puparium is impressed, so that when viewed from the side the 

 ventral outline in this region is seen to be concave. The segments show with toler- 

 able clearness. The two protractile spines of the larva are here thrust out and 

 immovable. Length of alcoholic examples 3.33""" (0.13 inch), dianu>ter 1"'"' (0.04 

 inch). * ■" * 



Imago. — The adult is a small brown fly with a wing expanse of about 0.25 inch and 

 measuring about one half this in length of body. The general color of some 

 exaujples is pale brown, while others are of a much darker Ijiown above and may 

 a])proach blackness on the sides of the thorax. The thorax is nuirked above by 

 three narrow stripes, the median and Avidest one extending upon the scutellum. 

 Head with a dark patch behind each eye and a dark dot including the ocelli. Com- 

 pound eyes widely separate, reddish brown. Mouth parts pale yellow. Antennie 

 with the basal segments yellow. Bristle black, with about five branches. Wings 

 hyaline, veins brown. Balancers pale. Legs pale. Abdomen pale Ijcneath. Terga 

 darker, with the hind half of each ring sometimes presenting the aj)pearauce of a 

 dusky cross band. Tip of abdomen black. The whole Ixxly is more or less thickly 

 clothed with pubescence, which in some regions, ]»articularly on the femora, tends 

 to become arranged in lines. On the head and thorax above are a number of 

 definitely arranged long black hairs. 



Length of alcoholic examples 2.2-3"'"' (0.09-0.12 inch). 



