90 THE HOUSE FLY—DISEASE CARRIER 
puparia of Musca domestica in January, 1911, in order 
to ascertain what proportion of the pupae were living, 
was surprised when a fully formed and active adult 
black Spalangia crawled immediately from the opening 
made by his dissecting needle. This will be described 
by Girault as Spalangia miisccc. A certain proportion 
of the house fly puparia are affected by this parasite in 
precisely the same way as are the puparia in Europe 
by Spalangia niger as described by Bouche. Mr. San¬ 
ford’s observation shows that the adults may be fully 
formed and ready to emerge at a very early date. 
Another European Pteromalid parasite, namely, Ste- 
nomalus muscarum, is recorded as being a parasite of 
the house fly pupa. 
Much attention has been given to the Chalcidoid 
parasites of the typhoid fly by A. A. Girault and G. E. 
Sanders, of the University of Illinois. In their first 
paper ( Psyche, December, 1909, pp. 119-132) they 
described an interesting form under the name Nasonia 
brevicornis from a series of 640 specimens, nearly all 
reared from puparia of various flies in the Office of the 
State Entomologist of Illinois at Urbana during 1908. 
They came from various decomposing materials, from 
which several species of flies were reared, but a num¬ 
ber undoubtedly came from Musca domestica. 
It is a minute, dark, metallic, brassy-green fly with 
clear wings and rather stolid and serious temperament. 
Girault and Sanders state that it heeds external influ¬ 
ences very slightly, and quietly and persistently gives 
its whole attention to reproduction. They found that 
