24 



Ni:\V YORK STATH MUSKUM 



The typhoid or house fly and disease 



M ttsca (Ju)ncstica Linn. 

 The house fly is sucli an extremely common species that de- 

 scription ai)pcars unnecessary. Dr Howard's investigations show 

 tliat fully 98;^ of the flies in houses are ordinary house flies. A 

 f ( \v others are associated with lliis dominant species. The staljlc 

 ll\, Stomoxys c a Ic i I r a n s Linn, may lie rather ahundant 

 ahout houses in the fall and is responsihle for the persistent helief 

 tliat under certain conditions the house fly bites. Invariably the 

 offender is this last named species, a form Avhich presents an ex- 

 tremely close g-eneral resemblance to the house fly and may be dis- 



FlG. II Typhoid or house fly: a, male, seen from above; b, proboscis and palpus frcm 

 the side; c. tip of the antenna; d, head of female; e. puparium; /. the anterior breathins- 

 pore or spiracle, all enlarged. (After Howard & Marlait, U. S. Dep't Agric. Div. Ent, 

 Bui. 4. n. s. 1896) 



tiuiruished 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. P o 1 1 e n i a r u d i s Fabr., a species some- 

 wliat larger than the house fly and easily recognized by the 

 ^ello^vish hairs upon the thorax. The small, yellowish fruit fly, 

 D r o s o p h i 1 a a m p e 1 o p h i a Loew, only about % inch 

 long, is sometimes rather abundant in houses and is invariably 

 found in association with overripe or decaying fruit. These 



