326 KANSAS UNIVERSITY SCIENCE BULLETIN. 



causing them to let go their holds on the rocks and drift into 

 the quiet slow-running water, I was unable to detect any in- 

 crease in the number of larvaj in the small narrow ripple be- 

 low. However, after a rain which caused a swifter current 

 between the ripples, I could sometimes find more larvae than 

 usual in the lower ripple. Ordinarily the current was sluggish 

 between the ripples. 



From our observations, there are three principal broods of 

 S. vittatuvi each year. One occurs in early spring, the fore 

 part of April; one in mid-summer, from the middle to the 

 latter part of July ; and one in mid-autumn, the latter part of 

 October, the time for these broods varying with the earliness 

 or lateness of the seasons. The general time for the spring 

 and fall broods seems to be at the heavy frost-line period. This 

 period varies with different species and in different states. 



Mr. Otto Lugger, the state entomologist of Minnesota, in 

 his report of 1896, pages 201 and 203, says in part on Simu- 

 lins flies: "The first species seen and felt occurs early in the 

 spring soon after the snow disappears. This species (name 

 not given) flies from May 13 to June 1. A little later in the 

 season, but chiefly during June and July, a somewhat larger 

 species, S. decorum Walker (.synonymous with vittatmn Zet- 

 terstedt, according to Coquillett) becomes numerous." Mr. 

 C. V. Riley, in the report of the United States Entomologist 

 for 1886, pages 342 and 343, refers to Mrs. Sara J. McBride, 

 of Mumford, N. Y., as stating in one of her articles that "the 

 perfect flies issued about April 1st." In the American Journal 

 of Science, volume I, 1913, under the heading, "A Destructive 

 Insect," mention is made that, "Contrary to the custom of 

 other insects, it {S. pecuarum) always appears when cold 

 weather commences in December, and as invariably disappears 

 on the approach of warm weather, which is about April 1 

 (Choctaw county, Mississippi), and continued to return at the 

 same season from year to year." 



In the report of the Commissioners of Agriculture for 1886, 

 Entomologist C. V. Riley says, in speaking of the southern 

 buffalo gnat (S. pecvarum) , as to its time of appearance: 

 "The first swarms were observed last year in Louisiana on 

 March 11, in Mississippi and Tennessee May 1, and in Indiana 

 and Illinois May 12. Small local swarms may appear some- 

 what earlier or later in the neighborhood of their breeding 



