1910] Girault and Sanders — Chalcidoid Parasites 9 
THE CHALCIDOID PARASITES OF THE COMMON HOUSE 
OR TYPHOID FLY (MUSCA DOMESTICA LINN.) 
AND ITS ALLIES.! 
By A. A. GrRAULT AND GEORGE ETHELBERT SANDERS. 
The University of Illinois. 
Habits in General and Biology. 
A. Oviposition. ‘This appears to be the only function of the 
female. When thus engaged she is not easily disturbed and the 
function is normally performed even in small capsules or vials, and 
in the insectary at various times, females were often observed attempt- 
ing to gain entrance to breeding-cages containing their hosts; in the 
case of large cages they were quite often successful and under certain 
conditions it was impossible to keep them out. ‘The following detailed, 
though fragmentary observations were made on ovipositing females. 
(1) - Sept. 12, 1908.— The female often faces towards the caudal 
end of the host puparium when engaged in ovipositing — on this date, 
in the cases of 8 host puparia (Phormia regina), apparent oviposition 
was observed once in four cases and twice in the other four — the 
times of these ovipositions were between 9:55 A. M. and 1:20 P. M. 
and the time required to deposit a single egg varied from 14 minutes 
to 16, averaging 74 minutes; the particular spot on the host puparium 
into which the ovipositor of the female was inserted was usually in the 
region of the 4th and 5th segments, but varied to the 6th and 7th or 7th 
and 8th. The hole made by the ovipositor was not distinct afterwards, 
but in many cases it became covered with a white mycelium-like 
growth the nature of which we have not determined. (2) On Sept. 
29, 1908, at 11:30 A. M., in the case of three virgin females ovipositing 
into the puparia of Phormia regina, the ovipositor was inserted for its 
full length for 3, 7 and 8 minutes respectively. (8) On Sept. 13, 
1908, a female was watched while ovipositing into a hard puparium 
of the Phormia. ‘The puparium was pierced by rotating the ovipositor 
and pressing it down, the force of the pressure often causing the organ 
to bend, when the rotary motion was more easily seen; this continued 


1Continued from Vol. XVI, p. 132, 
