PROCEEDINGS OF 



ENTOMOLOGICAL SOCIETY OF 



^ottian 



'^ 



JUN 22 1921 



VOL. 23 



JUNE 1921 



No. 6 



TWO NEW SPECIES OF DIPTERA. 



Bv CHARLES T. GREENE, Bureau of Entomology. 



The species treated below were referred to the author by Mr. 

 W. R. Walton, in charge of the Cereal and Forage Insect 

 Investigations of the U. S. Bureau of Entomology. Mr. Walton 

 also made the drawing of the puparia showing how they are 

 formed into a cluster or comb. 



The social habit of the larvae of S. sociabilis is curious. The 

 puparia are very firmly cemented together and it is impossible 

 to separate them without fracturing several cells of the comb. 

 The anal stigmata are unusually large in proportion to the size 

 of the puparium which is thickly, though shortly pilose, except- 

 ing immediately surrounding the stigmal field. The species is 

 new and may be characterized as follows: 



Sturmia sociabilis, new species. 



Male and female. Black, thickly covered with a pale gray pollen. Length, 

 male 5 mm.; female 6 mm. 



Female. Front one-fourth the total width of the head at vertex; thickly 

 dusted with a golden pollen which extends to the lower end of the sides of the 

 face; the usual frontal bristles reach to the middle of the second antennal joint; 

 two large orbitals directed forward; in addition to the usual bristles there are 

 several very small, erect hairs, some are in the form of a straight line close to the 

 eye margin; frontal stripe reddish brown, one fourth the width of the front 

 before ocelli and extending on each side of the ocellar triangle. Ocellar bristles 

 very small, converging forward. Facial depression dusted with silvery white; 

 ridges with only three or four bristles above the vibrissae. Antennae black, 

 reaching the lowest fourth of the face, faintly reddish on the outside near the 

 base of third joint; arista about as long as the antennae, reddish, thickened on 

 basal half. Vibrissae large. Palpi well developed; apex yellow, black on basal 

 half or more. Thorax with four narrow, black vittae; four posterior dorso 

 centrals. Scutellum black, faintly yellowish at the apex; one discal pair of 

 macrochaeta; three marginal pairs and an additional smaller apical pair, 

 decussate. Four sternopleurals. Abdomen all black; second segment with one 

 pair median marginal, one pair lateral; also a very narrow median black stripe; 

 third segment with four marginal pairs; no discals on either segments. Legs 

 black; knees very narrowly reddish; middle tibia with one large bristle on front 

 side near the middle. Hind tibiae evenly ciliated with one large bristle in the 

 middle. Wing with one large bristle at base of third vein. 



Male. Same as female except the front is slightly narrower ami there arc no 



