THE MOUNT DESERT REGION 385 



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

 .June 21-Sept. 11. 



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



S. nitens Zett. ''Narrows," Aug. 13. 



S. pomus Curr. Bar Harbor, Aug. 



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

 7-Aug. 20. 



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



S. RiBEsn var. vittafrons Shan. Bar Harbor ; Long Pond ; 

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



S. torvus 0. 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. 



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

 bor, June 9-22. 



S. wiedemaxnt Johns. Bar Harbor; " Narrows," June 9- 

 Aug. 13. 



Epistrophe Walker 



E. arcticus Zett. Bar Harbor, Sept. 11, 1922. 



E. diversipes Macq. Common, June 8- Aug. 11. 



E. fisheri Walt. S. W. Harbor, Aug. 22.^ Station F263. 



E. geniculatus Macq. S. W. Harbor; Green Mt. ; Bar Har- 

 bor, June 22-Sept, 11. 



E. genualis Will. Bar Harbor ; Salisbury Cove ; S. W. Har- 

 bor, June 7-21. 



E. grossulariae Meig. Bar Harbor; Green Mt., July 22-25. 

 Station F265. 



