2 University of Michigan 



omnipresent. So obnoxious and persistent are some of the 

 pests that the cattle are forced to feed largely at night, and 

 are kept shut up in dark sheds during the day when the flies 

 are active. On account of a general lack of flowers and 

 flowering shrubs from July 2 to 15, 1913, the Syrphidse were 

 not present in much variety of species. A small patch of 

 raspberry bushes in flower made a center of attraction for 

 many Diptera, and a number of species were collected about 

 these bushes that would otherwise have been overlooked. 

 From July 18 to August 2, 1914, conditions were rather better 

 as regards flowering vegetation, and many species of flies 

 were taken on the blossoms of spiraea, tansy, dewberry, etc. 



The conditions observed lead to the conclusion that the 

 optimum of the collecting season for Diptera in the region is 

 from August i to 15, although of course some species have 

 disappeared by that time and others probably have not ap- 

 peared. Without doubt a professional dipterist would find 

 Whitefish Point an excellent region in which to collect, and 

 on account of the variety of conditions, with the diverse flora 

 and the relatively short and rapidly succeeding seasons, sev- 

 eral summers' work would undoubtedly be well repaid. 



The following list does not pretend to be complete in any 

 sense, but the paucity of investigations that have been made 

 in the region seem to afford a reason for its publication. All 

 specimens represent time taken from the writer's coleoptera 

 studies with the hope of stimulating further research in the 

 region. 



The writer wishes to express his indebtedness to Mr. H. S. 

 Harbeck of Philadelphia for the determination of the majority 

 of the forms. The list is arranged according to Prof. J. M. 

 Aldrich's "Catalogue of North American Diptera" (Miscl. 

 Pub., Smith Inst., vol. 46). 



