332 BIOLOGICAL SURVEY OF 



S. LATiFASciATUS Macq. {abhreviatus AVill.)- Salisbury Cove, 

 July 23-24. 



S. RiBEsii Linn, Common, July 10-Sept. 9. 



S. RIBESII var. viTTiFRONS Shan. Bar Harbor; Long Pond; 

 Salisbury Cove; S. W. Harbor, June 8-Sept. 6. 



S. RECTUS 0. S. Bar Harbor ; Green Mt. ; S. W. Harbor, July 

 7-Aug-. 20. 



S. DAXA 0. S. S. W. Harbor; Bar Harbor; Salisbury Cove, 

 June 21-Sept. 11. 



S. NiTENS Zett. ' Narrows, ' Aug. 13. 



Si JOHNSONi Curr. Bar Harbor, June 22-23. 



S. LiMATUS Hine. Bar Harbor, June 13, 1931. 



S. VENUSTUS Meig. Bar Harbor ; Salisbury Cove ; S. W. Har- 

 bor, June 9-22. 



E. EMARGiNATus Say. Bar Harbor, June 15- Aug. 14. 



S. FELIX 0. S. Echo Lake, July 17. 



S. TORVus O. S. Common, June 15-Sept. 22. During the first 

 warm days in spring, the adults emerge and eggs are laid 

 on the first colonies of aphids appearing on the shoots of 

 various plants, and they continue through the summer liv- 

 ing on various forms of aphids and undoubtedly destroy 

 many of the sexual females in September. Taken as late 

 as September 22nd. Owing to an open winter, there was a 

 large aphid population in the spring of 1937, and by the 

 first of July these flies were in enormous quantities and 

 would rise in swarms, while at the same time the numbers in 

 the other species in the genus remained the same as other 

 years. 



Baccha Fabricius 



B. coGisTATA Loew. Bar Harbor; Echo Lake; N. E. Harbor 

 (Minot), June 11-Aug. 25. 



