24 NEW YORK STATE MUSEUM 
The typhoid or house fly and disease 
Musca domestica Linn. 
The house fly is such an extremely common species that de- 
scription appears unnecessary. Dr Howard’s investigations show 
that fully 98% of the flies in houses are ordinary house flies. A 
few others are associated with this dominant species. The stable 
fly, Stomoxys calcitrans Linn. may be rather abundant 
about houses in the fall and is responsible for the persistent belief. 
that under certain conditions the house fly bites. Invariably the 
offender is this last named species, a form which presents an ex- 
tremely close general resemblance to the house fly and may be dis- 

Fic. tr Typhoid or house fly: a, male, seen from above; b, proboscis and palpus frem 
the side; c, tip of the antenna; d, head of female; e, puparium; f, the anterior breathing- 
pore or spiracle, all enlarged. (After Howard & Marlatt, U. S. Dep’t Agric. Div. Ent, 
Bul. 4. n. s. 1896) 
tinguished therefrom at once by its bite. It occurs, as a rule, about 
the stable. Another fly liable to be abundant about houses in the 
fall is the cluster fly, Pollenia rudis Fabr., a species some- 
what larger than the house fly and easily recognized by the 
yellowish hairs upon the thorax. The small, yellowish fruit fly, 
Drosophila ampelophia Loew, only about 1% inch 
long, is sometimes rather abundant in houses and is invariably 
found in association with overripe or decaying fruit. These 
