CHAPTER XVI 



THE STABLE FLY, STOMOXVS CALCITRANS LINN. (fig. 80) 



Owing to a general resemblance which this species bears to 

 Miisca domestica, and to the fact that it is a blood-sucking species, 

 it is frequently mistaken for Musca domestica, which is supposed 

 to " bite " under certain conditions. This has led to the popular 

 but obviously inaccurate idea that house-flies bite. The biting 

 fly is usually Stomoxys calcitrans. It is naturally an out-door 

 species and loves the sunlight, coming indoors usually on the 

 approach of rain when the sky is dull, hence it has been named 

 the "Storm-fly," and this fact, namely, the presence of *S^. calcitrans 

 indoors during dull weather, has led to the popular misconception 

 that house-flies bite during such meteorological conditions. 



In England and Canada I have found this species common 

 and widely distributed, occurring especially in the country from 

 July to October. In the United States it appears to be abundant 

 during the same period. During these months it may be often 

 found in houses, although Hamer's observations (1908) appear to 

 indicate that the presence of cowsheds in which they occur in 

 large numbers, does not affect their numbers in houses. In 

 England I have found S. calcitrans in large numbers in the 

 windows of a country house in March and April, and it may 

 be found frequently out-of-doors on a sunny day in May and 

 throughout the ensuing summer months. It occurs occasionally 

 in-doors in November and is commonly found in cowsheds and 

 stables throughout the winter months. Its association with the 

 cowsheds and stables has given it the name of stable fly, by which 

 it is now generally known. 



