SYNOPSIS OF NORTH AMERICAN SYRPHID^. 89 



Syrphus nigripes Loew, Ceutur., vi, 44. — Cuba. 



Syrphus praeustus Loew, Ceiitnr., vi, 45. — Cuba. 



Syrphus quadrifasciatus Bigot, in R. de la Sagra, etc., 804; pi. 20, fig. 5.— Cuba. 



Syrphus radiatus Bigot, in R. de la Sagra, ■tetc, 804. — Cuba. 



Syrphus stegnus Say, J. Acad. Phil., vi, 16:5, 1 ; Compl. Wr., ii, 358.— Mexico. 



DIDEA. 



Didea Macquart, Hist. Nat. Dipt., i, 508, 1834. 

 Enica Meigen, Syst. Beschr., vii, 140, 1838. 



Large, metallic black, not bare species, with flattened yellow or 

 greenish-yellow banded abdomen. Head hemispherical, broader than 

 the thorax. Anteunse short, third joint oval, with a basal, bare arista. 

 Face gently concave below the antennte to the obtuse tubercle, thence 

 receding; chiefly yellow. Eyes contiguous in the male, bare or pilose. 

 Thorax without yellow on the dorsum, though it may bepollinose near 

 the sides. Scutellum yellow translucent. Abdomen broadly oval and 

 flattened, broader and much longer than the thorax. All the legs slen- 

 der. Wings comparatively short and broad ; third vein with a consid- 

 erable sinuosity bending into the first posterior cell; otherwise as in 

 Syrphus. Type of genus, D. fasciata Macquart, Europe. 



This genus cannot be distinctly separated from Syrphus; as its chief 

 characteristic, the curvature of the third vein, is also found in one of 

 the varieties of Sytyhns nrcuatvs. It is, however, useful, and may be 

 retained. 



TABLE OF SPECIES. 



1. — Third joint of antennte obtusely pointed at tip ; eyes bare ; abdominal cross- 

 bands broader toward, but not quite reaching, the lateral margin of the 



abdomen fuscipes 



Third joint of anteunie obtusely I'ounded at the tip 2 



2. — Eyes bare; cross-bands broadly interrupted. (See Syrphvs arcuatus var. lapponi- 

 ctis. ) 

 Eyes thinly pilose ; the abdominal cross-bands reach narrowly quite to the lateral 

 margin laza 



Didea fasciata fuscipes. 



Didea fuscipes Loew, Ceutur., iv, 82; Osten Sacken, Cat. Dipt., 245, note 212. 

 Habitat. — Connecticut, Pennsylvania! 



$ ,9 . Length, 11""". Eyes bare. AntennsB black, the third joint at 

 the base sometimes reddish, elongate oval, obtusely pointed at the tip; 

 arista reddish. Face yellow, with a small, elongate, brownish spot on 

 the tubercle. Front yellow, with two brownish spots above the anten-' 

 nre, or, in the female, with an inverted V-shaped brown stripe connected 

 with the black of the npper part of the front. Orbits thickly yellow- 

 ish polliuose, and with a fringe of yellowish- whitish pile. Thorax shin- 

 ing greenish black, on the meso, ptero, and sternopleurfe- yellow, thickly 

 covered with similar colored i:>ollen and pile. Scutellum light yellow, 

 translucent. Abdomen black, with four yellow cross-bands, the first 



