574 HOWARD 



June 14 from miscellaneous faeces collected on the 13th. The 

 same species was also captured and bred at Travilah, Maryland, 

 and was captured at Snickers Gap, Virginia, on exposed fceces, 



Fig. 24. Morellia micatis : broken puparium at right — enlarged (original). 



and at Leesburg, Virginia, in a privy. It seems, in fact, to be 

 one of the most abundant of the true breeders in human excre- 

 ment and one of the most specific. It apparently hibernates in 

 larval and pupal states, entering the ground just below the ex- 

 crement on which it has fed. 



Muscina stabulans Fallen. 

 This fly is com.mon throughout Europe and occurs also in 

 North America. The larvas usually feed upon decaying vege- 

 table substances, fungi, etc., but it is recorded in Europe as 

 feeding upon the larvas of Lepidoptera and bees. Schiner also 

 states that it breeds in cow dung, while Megnin records its 

 puparia as having been found upon the mummified bodies of 

 children. In the course of the cotton worm investigation by 

 this office it was found to prey upon the pupa of the cotton 

 caterpillar. It was at first considered as a parasite, but Riley 

 decided that it feeds on rotten chrysalids only. During the 

 work of the Gypsy Moth Committee, the same species was reared 

 from the pupa of the gypsy motli, possibly under similar con- 

 ditions, i. e., from pupae which were alread}' dead before the 

 eggs of the fly were deposited. Gillette, in Bulletin 19 of the 

 Colorado Agricultural Experiment Station, records the fact that 



