Banks, Greene, McAtee, and Shannon — Dist. of Col. Diptera. 183 



1906, McAtee. Common; season April 28 to September 30; hovers over 

 flowers and in sunny spots. 



S. PERPLEXus Osburn. — Plummers Id., Md., April 4, 1915; April 16, 

 1915, May 7, 1916, Shannon; Great Falls, Va., April 28, 1915, Greene; 

 Falls Church, Va., April 26, October 6; Great Falls, Va., April 15, Banks. 



S. RECTUS O. S. — Washington, D. C. , no date, D. H. demons; Bladens- 

 burg, Md., September 23, 1915; Rosslyn, Va., April 23, 1913; Falls 

 Church, Va., April 22, 1913, Shannon; Plummers Id., June 4, 1915; May 

 8, 1915; June 22, 1903, E. A. Schwarz; September 29, 1912, P. R. Myers; 

 Dead Run, Va. , June 22 and 29, 1915 ; October 28, 1915 ; Cupids Bower 

 Id., Md., May 30, 1915; Great Falls, Va., April 28, 1915, Shannon; 

 September 12 and 28, Banks; Beltsville, Md., June 14, 1914, McAtee; 

 Plummers Id., Md., August 4, 1907, A. K. Fisher; Virginia near Plum- 

 mers Id., Md., April 23, 1916, H. L. Viereck ; September 29, 1915, 

 McAtee. 



S. RiBESii Linnaeus. — Marshall Hall, Md., September 17, 1908, F. H. 

 Chittenden; Beltsville, Md., June 14, 1914, July 30, 1916, McAtee; Plum- 

 mers Id., Md., April 12, 1908, A. K. Fisher; Washington, D. C, October 

 2, 1906, McAtee; May 17, 1916; Falls Church, Va., June 8, and 16, Sep- 

 tember 19, and October 6, Banks; August 23 to 29, 1913, Greene; Glen- 

 carlyn, Va., June 21; Great Falls, Md., July 12, Banks; Great Falls, 

 Va. , April 20, 1916, McAtee. S. ribesii var. vittafrons Shannon. — Lake- 

 land, Md., November 11, 1909, F. Knab; Maryland near Plummers Id., 

 April 17, 1903, W. V. Warner; April 22, 1903, H. S. Barber; Cabin John, 

 Md., September 13, F. Knab; Great Falls, Va., September 25, 1913; 

 April 20, 1913, Shannon; September 24, Banks; Rosslyn, Va. , April 23, 

 1913, Shannon. 



S. TORVUS Osten Sacken. — Common and widely distributed; extreme 

 dates of collection for spring are : March 26 to June 1 and for fall Sep- 

 tember 6 to December 9. No specimens taken during the summer months. 



The species of Syrphus are mostly not found on flowers, but hovering 

 in air in sunny places sometimes ten or more feet above the ground. The 

 larvae are aphid feeders. 



S. XANTHOSTOMUS Willi.ston.— Plummers Id., Md., May 23, 1911, P. R. 

 Myers. 



Xanthogramma Schiner. 



X. AEQUALis Loew. — Virginia near Plummers Id., July 20, 1912, P. R. 

 Myers. 



X. DiviSA Williston. — One from Falls Church, Va., June 2, Banks, 

 agrees well with type, but it is hardly more than a variation of felix, the 

 spots being smaller and consequently farther apart. 



X. EMARGiNATA Say. — Maryland near Plummers Id., August 5, 1913, 

 Shannon; Cabin John, Md., May 15, 1904, F. Knab; Falls Church, Va., 

 August 26, 1913, Greene; Glencarlyn, Va., June 17; Chain Bridge, Va., 

 May 21, Banks; Great Falls, Va., October 3, Banks. 



