INSECT FAUNA OF HUMAN EXCREMENT 575 



he found dying squash plants with the stems honeycombed be- 

 low the ground by a white maggot. From these maggots he 

 reared Mnscina stabidans. Coquillett (' Insect Life,' vii, pp. 

 338, 339) determines this insect as Cyrtoncura casia and doubts 

 the vegetable-feeding habit. In this case the eggs were prob- 

 *ably to be found in the manure which was placed about the 

 plants, or else the heavy manuring 

 attracted the flies. In 1891 the fly 

 was reared upon masses of the 

 larvae and pupa of the imported 

 elm-leaf beetle which had congre- 

 gated about the roots of trees upon 

 the grounds of the U. S. Depart- 

 ment of Agriculture (see Annual 

 Report of Department of Agricul- 

 ture for 1892, page 167). Sep- 

 tember 26, 1900, it was reared by 



Mr. Chittenden of this office from 



, 1 • 1 , J 1 . Fig. 25. Dluscina stabulans — 



a rotten squash which had been m- . ,, . . ., 

 ^ _ enlarged (original). 



fested with the pickle worm {Ma7'- 



garonia nitidalis). It thus seems to be an insect of somewhat 



variable habits, attracted, however, as a rule, to foul animal 



matter. 



In May, 1899, ^^ ^^^ captured at Washington upon human 

 excreta exposed for six hours. This same thing occurred on 

 six different exposures during this month. A typical case 

 which may be described was that of observations on a mass of 

 excrement found in an alleyway back of Tenth Street in south- 

 west Washington, on June 6. It was a hot, summer day with 

 a temperature of 92° F., and the small houses had kitchens 

 practically opening on the alley. The writer and Mr. Pratt 

 collected, that morning, on this excremental mass, Mnscina 

 stabulans^ Lucilia ccesar, Phormta terrcsnovce^ Call/'pkora ery- 

 throcephala, Limosina albipennts, Phorbia cinerella, and seven 

 specimens of Musca domesttca, the common house fly. This is 

 a typical case, illustrating the ready transfer of diseases of the 

 alimentary tract to food in the poorer and dirtier parts of the 

 city. Suppose, for example, that the excrement in question had 



