81 



short, about as wide as long^ joints beyond the third becoming 

 darker distally, darkest at base of each, infuscate, with verticils 

 of stiff black hairs and a dense pubescence. Prothorax yellowish 

 brown above with two or four darker stripes, the middle pair 

 broadest before, mesonotum and metanotum paler, pleura gray;, 

 knob of halteres infuscated. Abdomen and male forceps yellow, 

 with a rather broad black median shade, faint on the first seg- 

 ment and distinct on the others, sometimes involving nearly the 

 whole abdomen. Hypopygium very large; dorsal piece pubescent, 

 tumid, inflated; upper diArision emarginate at tip, its lateral angles 

 bilobed, outer lobe the longer and curved outwards and upwards. 

 Lower division of dorsal piece emarginate at tip. Coxae gray, legs 

 yellowish brown, darkening distally to the tarsi, which are moslJy 

 black; femora and tibiae a little darker at apex. Wiugs slightly 

 infuscated, darker at tip, beyond the basal cells; the base of wing, 

 its front margin (costal and marginal cells), and a narrow area 

 behind the fifth longitudinal, all yellow. Stigma dark, and the 

 usual white space stretching from it along the small cross-vein 

 and across the discal cell, whitening the veins in its course. No 

 other white spots. 



The female, more yellow than the male, especially abdomen, wing 

 veins, and legs, the tarsal joints in one specimen showing but little 

 brown. The palpi, two basal joints of the antennae, and first three joints 

 oi the flagellum yellow, the remaining joints dark brownish at the base 

 only. The short horny valves of the ovipositor are slightly 

 curved, and are covered above by a thin, leathery, three-lobed flap, 

 the middle lobe being nearly concealed beneath two outer^ 

 superior ones. 



We do not yet know of the occurrence of this species in 

 Northern Illinois, although it is very probably not less common 

 there than in the central and southern part of the State, where 

 the winged insect is, in its season, one of oar most abundant 

 species. 



LIFE HI&TORY AND INJURIES. 



This species hibernates as a larva nearly or quite full grown, as 

 shown by our collection made in Edwards county April 6, 1888, 

 and in Effingham county on the 16th. At Edgewood nearly all 

 had changed to the pupa by the 3d May, at which time a single 

 larva was also found, and a single empty pupa case. Breeding- 

 cage specimens from Southern Illinois began to emerge May 4, 

 and continued to do so until the 28th May. By May 10, these 

 flies were found common in meadows near Carbondale; and 

 at Urbana, May 19, they appeared in numbers at the electric light 

 and flying about in meadows. The latest specimens ol the season 

 were collected May 31. No eggs were obtained, but pairs were 

 seen in copula late in May (19 to 31) in both fields and breeding 

 cages. The immediate copulation of the imagos, and the immense- 



