Syrphidae of Nebraska 17 



2. Face partly or wholly yellow, scutellum yellow, partly yellow or 

 black (certain species of Paragus) Syrphini 



Melanostomini 

 key to the genera 



1. Wings shorter than abdomen; abdomen depressed, long-ellipti- 

 cal; front and middle tarsi elaborately developed; vertical tri- 

 angle large and prominent Pyrophaena 



Wings longer than the abdomen 2 



2. Front tibiae slender in both sexes Melanostoma 



Front tibiae and tarsi of male dilated; those of female slightly 

 widened Platychirus 



Pyrophaena Schiner 



Only one Nebraska species of this genus. 



Pyrophaena ocymi (Fabricius). Syst. Ent., iv, 309 (1775); Schiner, 

 Fauna Austr., i, 297 (1862). 



A s from Halsey, Thomas County, June 19, 1912 (J. T. 

 Zimmer). 



Melanostoma Schiner 



KEY TO THE SPECIES 



1. Tubercle of face not at all prominent, indistinct; spots on ab- 

 domen quadrate {$), oval ($) and yellow mellinum 



Tubercle of face prominent, distinct; abdomen bluish green, 

 metallic with inverted wine glass velvety-black opaque areas on 

 third and fourth segments, the handle of the glass reaching the 

 anterior margin of the segment concinnum 



Melanostoma melinum (Linnaeus). Syst. Nat., 10th ed., 594 (1758). 

 1858. scalaris Osten Sacken, Cat. Dipt., 121. 



Two 2 $ are represented in the University collection, and 

 both were taken at Glen, Sioux County, on August 8 and 9, 

 1905, respectively. 



123 



