DIPTERA OF MINNESOTA. 



115 



of "skipping"' which characterizes 

 the cheese mite larva is performed 

 by the maggot seizing the posterior 

 part of its body, with its mouth 

 armature, pulHng hard and sudden- 

 ly releasing its hold. In this way 

 it can "jump" quite a distance. 

 This insect has caused packers pe- 

 cuniary loss by infesting bacon and 

 ham. The adults of this family 

 dre active flies, both when using 

 their legs and in flight. Aldrich 



(1904) gives 29 species as occurring in North America. 



Taken in Minnesota: Sepsis violacea, Meig. ; Themira putris, 



Linne. ; Piophila casci. Tvinn., So. Dak. 



MICROPEZIDAE. 



Fig. 109. Piophila casei, fly which produces 

 the Cheese Mite or "Skipper." Original. 



Fig. 110. Calobata antennipes. Lugger. 



