308 CALIFORNIA ACADEMY OF SCIENCES [Pkoc. 4th Ser. 



Family MUSCID^ 



Fig. 35. Pollenia rudis (Fabr.) 



Small to medium sized, short, and usually hairy flies. The 

 antennal arista is usually plumose to the tip, the first pos- 

 terior cell narrowed or closed and the squamas are large. 

 They are disease carriers and very important economically. 

 The common house-fly, or typhoid-fly as it might better be 

 called, is found all over the world. The blow-flies and blue- 

 bottle flies are also widely distributed. 



The Stomoxyinae include blood-sucking species. In this 

 group are the horn-flies, stable-flies and tsetse flies. 



706. Pollenia rudis (Fabr.) 



Medford, VIII-15; Corvallis, IX-4. The cluster-fly is 

 known to be parasitic in earthworms. 



707. Cynomyia cadaverina Desv. 

 Corvallis, IV-10 to VII-10. 



708. Calliphora erythrocephala (Meig.) 

 Common III to XII. This is the common blow fly. 



709. Lucilia caesar (Linn.) 



Common everywhere. Breeds in excrement, garbage and 

 carrion. 



