THE SYRPHIDAE OF OHIO 85 



28 P. hyperboreus Staeger. Numerous specimens Columbus, Lake- 

 ville, Sandusky, Ira, Vinton, Medina, Hawkins, Milan, Newark; mid- 

 April to late July. (Figs. 214, 240, 244. ) 



29 P. peltatus Meigen. One male, three females, Wauseon, Akron 

 Hincklej- late July to late August. (Figs. 215, 242.) 



30 P. quadratus Say. Ten males, four females, Columbus, I^ake- 

 ville, Sandusky, Ira, Hinckle}', Danville; early Aj^ril to earh^ September. 

 (Fig. 216.J 



Melanostoma Schiner 



I Hind metatarsi not thickened, abdomen in the male with three pairs of qnad- 

 rate reddish-3ellow spots, tubercle of face not prominent; abdomen in the 



female oval with four pairs of triangular spots mellinum 



Hind metatarsi of the male always somewhat thickened; bands of abdomen 

 metallic or greenish, not reddish-yellow; pollen of face (uniform or) some- 

 what ripple like but not of distinct circular spots; pile of thorax dusky 

 obscurum 



31 M. mellinum Lin ne. Numerous specimens, Columbus, Lake- 

 ville, Sandu.sky, Medina, Ira, Hinckley, Kent; middle of April to middle of 

 August. 



32 M. obscurum Say. Very common. Specimens from Columbus, 

 Lakeville, Cincinnati, Vinton, Hinckley, Wauseon; late March to late 

 August. (Fig. 250.) 



Didea Macquart 



33 D. fasciata Macquart var. fuscipes Loew. For description of 

 stages see Part II, p. 58. 



Syrphus Fabricitis 



1 Three principal yellow bands of abdomen entire, the second and third ones 



not reaching the lateral margin; face with a brown stripe americanus 



First yellow cross-band interrupted, the others entire 2 



Three principal yellow bands interrupted; eyes bare; abdominal spots of 



third and fourth segments distinctly arcuated 10 



2 Abdomen narrow, with nearly parallel sides in the male; in the female the 



fifth segment half as long as the fourth diversipes 



Abdomen distinctly oval, the fifth segment in the female less than half as long 

 as the fourth 3 



3 Femora black at the base 4 



Femora yellow at the base 7 



4 The first, second, and third abdominal cross-bands do not reacli the lateral 



margin, eyes bare, clieeks black americanus 



Tlie second and third yelluw-l)an(ls reacli the margin 5 



