1917] Bishopp—Nose Fly and other Species of Gastrophilus 185 
preceding four or five years. In working northward and west- 
ward the dates set by farmers as the time of first appearance 
became earlier until Minot, N. D., was reached where a rather 
authoritative record was secured of the occurrence of the fly 
eighteen years before (1896). 
During the spring of 1915 and 1916 Mr. W. E. Dove and the 
writer made further inquiry into the distribution of this insect in 
parts of South Dakota and Minnesota, and Mr. Dove was located 
in this region and made further inquiry regarding the history of 
the spread of the insect during the summers of 1915 and 1916. 
His work largely substantiated the earlier findings. 
To supplement personal observations and questioning, a large 
number of letters of inquiry were sent to farmers and horse breeders 
in the region from Indiana to Washington, and Kansas to Can- 
ada. About 350 replies were received. One correspondent each 
in Colorado, Idaho, Utah and Oregon, and three in Washing- 
ton replied that the nose fly is present, but there is reason to be- 
lieve they were mistaken in the identity of the insect, except pos- 
sibly two in eastern Washington.! All reports from Indiana, 
Kansas and Missouri were negative. Three affirmative ones 
were received from Illinois and two from Wisconsin.! While 
neither was corroborated with specimens it is practically certain 
that infestations, possibly more or less local, occur in these states. 
Montana and North and South Dakota are generally infested at 
this time and central western Minnesota, northern Nebraska and 
northeast Wyoming undoubtedly so. It appears from replies and 
personal examinations that the insect is more or less scattered over 
Iowa, but probably not numerous except in the northwest part. 
In Canada we have learned through correspondents of the pres- 
ence of the nose fly in southern Manitoba and Saskatchewan. 
A very interesting discussion regarding the occurrence of the 
nose fly in Canada appeared in the Proceedings of the Entomologi- 
cal Society of Ontario for 1915. Professor Lochhead there pre- 
sents extracts from some correspondence from men in western 
Canada. It is my opinion that these correspondents, except one 
from Ontario, refer especially to G. hamorrhoidalis although one 
sent in specimens of G. nasalis, which is much more easily caught. 
1Since this article was submitted for publication the localities in Wisconsin and Washington 
have been visited. The nose fly is well established in western Wisconsin but its presence in 
central Wisconsin and eastern Washington could not be verified. 
