December, '13] BRUES: STOMOXYS DISTRIBUTION 465 



particularly if these are constructed of wood and painted. Even in 

 the summer they are attracted to such warm surfaces in the full glare 

 of the sun except during the middle of the hottest days; they then 

 migrate to places illuminated by more slanting sunshine. In this 

 way during a single day they will successively congregate upon such 

 portions of a barn as present the desired warmth and sunshine. By 

 October the activity of the flies is much diminished, and on cool 

 mornings they remain in a dormant condition. However, as soon 

 as the air becomes warmer, later in the day, they again become ac- 

 tive, and at this time of the year almost replace the house fly which 

 has decreased greatly in numbers. Even after a severe frost, they do 

 not disappear entirely if the weather again becomes warm. In warmed 

 stables thej' persist in greatly decreased numbers throughout the 

 winter in a semi-active state, and stable-men recall having been bit- 

 ten by them when sitting about heated stable stoves in the dead of 

 winter. 



There are a number of published references to the occurrence of 

 the stable fly in ^Massachusetts, but they do not add materially to 

 the above statement. It is interesting to note, however, that Harris ^ 

 as early as 1842 speaks of cattle and horses being much tormented 

 by the bites of these insects. 



Michigan. — Prof. R. H. Pettit informs me in a letter that the 

 stable fly is common throughout southern IMichigan and that he has 

 seen them extremeh' abundant in the northern part of the state a 

 short distance from Mackinaw. 



Minnesota. — Washburn - in his Diptera of Minnesota says that the 

 stable fly is found in large numbers about stables in Minnesota. 



Professor Washburn has also been so good as to inform me by 

 letter that his observations would indicate that the species is quite 

 common in the neighborhood of all the towns over the state. 



Missouri. — ^Mr. Leonard Haseman writes from Columbia, Mo., that 

 he has never seen the stable fly so abundant in any part of the United 

 States where he has been, as it is in Missouri. He says that it is a 

 great scourge of live stock and aside from the house fly and the horn 

 fly, the most abundant fly breeding in horse-manure in the region 

 about Columbia. 



Mississippi. — ^Bishopp ^ states that the stable fly occurs commonly 

 in Mississippi and sometimes becomes a considerable pest of live stock. 



Montana.— Mr. William :\I. Mann tells me that the stable fly is 

 a common insect in ^lontana. 



1 Insects Injurious to Vegetation, p. 412. 



2 Tenth Ann. Kept. Entom. Minnesota, p. 148 (1905—). 

 • Joum. Econ. Entom., Vol. 6, p. 115 (1913). 



