402 



NORTH AMERICAN DIPTERA 



Family Metopiidae— The Flesh Flies 



Sarcophaga sarraceniae. 



Flies of medium to moderately small size, the abdomen usually dark 

 and tessellate or metallic green or blue. 



Front in both sexes broad, usually somewhat narrowed in the males, 

 rarely very narrow; face variable; vibrissa present; antennse long or 

 short, the arista plumose, pubescent or bare. Abdomen composed of four 

 segments in the males, the fifth short in the females; abdominal bristles 

 usually strong, at least on the apical segments. Hypopleura with a row 

 of bristles; postscutellum developed only in MescinbrineUa. Apical cell 

 usually open, rarely closed and petiolate, usually ending far before the 

 apex of the wing. 



As here considered this family comprises the Sarcophagidfe, part of 

 the MuscidaB and part of the Taehinidae of Williston's Manual. The 

 absence of the postscutellum distinguishes it from the Tachinidiig while 

 the presence of hypopleural bristles separates it from the Muscidcc and 

 the well developed mouth parts from the (Estridae. A study of pupal 

 and larval characters indicates that the association of the genera now 

 included in the family is a natural one, although the genus 3Iesem- 

 hrinella is a doubtful member. 



Insofar as known the larvae are flesh feeders, parasites or scaven- 

 gers on excrement and all have the posterior spiracles situated within 

 a deep depression. 



