168 PROCEEDINGS ENTOMOLOGICAL SOCIETY 



AN EASTERN CHILOSIA WITH HAIRY EYES. 



(Diptera, Syrphidce.} 



BY R. C. SHANNON, Bureau of Entomology. 



Chilosia primoveris, new species. 



Male: Robust species; shining, dark metallic green. Eyes hairy; ver- 

 tex with long light colored hairs with black ones intermixed; frontal tri- 

 angle with long erect black hairs and a furrow running down the middle; 

 first two antennal joints deep reddish brown, the third a shade lighter; 

 arista concolorous with the third joint and with microscopic pubescence 

 on basal third. Face with light colored hairs and very fine pubescence, 

 the tubercle distinctly nearer the oral margin than to base of antennae and 

 projecting far beyond latter. 



Dorsum of thorax with rather long and dense whitish pile and meso- 

 pleura with long black hairs; post-alar callosities with fine long black and 

 whitish hairs in tufts; scutellum covered with long whitish pile like that on 

 mesonotum and with a few coarser black or yellow ones on the margin. 



Abdomen slightly narrower than thorax, shining dark metallic green, 

 with rather thick white pile. 



All the femora black, their tips brownish-yellow, tibise yellow, with 

 broad black rings around the middle; tarsi on outer side more black than 

 yellow, on under side largely yellow. 



Wings tinted with yellow, their bases dull brown which merges into yel- 

 low as it spreads out over the wings. Spurious vein weak; last section of 

 fourth vein with two angulations which have very shoirt stumps at their 

 apices; the second spur, which projects into the first posterior cell, some- 

 times obsolete, the part of the vein beyond this last broadly curved out- 

 ward. Length: 6-8 mm.; wing 6-7.5 mm. 



Female: Frons narrower than one eye, narrowing towards vortex, with 

 a broad transverse depression a short distance above antennas and a weak 

 longitudinal groove running from ocelli to the depression; frons clothed 

 with light yellow erect pile which is longer in the ocellar region. Facial 

 tubercle more prominent than in the male. 



Mesonotum with some coarser hairs scattered through the light pile. 

 Mesopleura? with light pile. 



Abdomen broader than thorax and with shorter pile than in the male. 

 Last section of fourth vein with only slight trace of the second angulation, 

 and rarely with trace of stump. Length 5-7 mm.; wing 5-7 mm. 



Type locality: Plummers Island, Md. (Male type, April 16, female 

 allotype April 25, 1915, R. C. S. coll.) 



Type Cat. No. 19786, U. S. N. M. 



Described from 45 specimens; paratypes from Plummers Island, Md. 

 opposite Plummers Island, Cabin John and Great Falls, Md.; Dead Run, 

 Fairfax Co., Va., April 7-25. (R. C. Shannon, J. C. Crawford, and W. L. 

 McAtee, collectors). 



This species runs to C. petulca in the table in Williston's Synopsis 

 of the North American Syrphidse. In comparison with the type of that 

 species it is smaller, more robust, and darker shining metallic green. The 

 arista of petulca is longer and with distinct pubescence to the tip; all three 

 antennal joints are more yellow; the frons is yellow at base of antenna}. 

 The body pubescence of petulca is very short and thinly scattered, the hairs 

 on the scutellar margin stronger, shorter and black. The wings of petulca 

 are comparatively longer; the last section of the fourth vein is much 

 nearer the wing margin and runs nearly parallel with it. Its legs are of 

 a more uniform color. 



Actual date of publication, September 18, 1915. 



