218 
Journal of Agricultural Research 
Vol. I, No. 3 
the tip of the abdomen of the male is curved down at one side of the 
abdomen of the female while he clings to her wings and body. 
oviposition 
Oviposition began in the cages about nine days after the emergence of 
the female. The stage of the host selected is the full-grown larva in its 
cocoon. In no case was any other stage attacked. 
The act of oviposition (PL XX, figs. 2 and 3) was observed many times. 
The insect first explores the surface of the cocoon carefully with her 
antennae. Then standing “on tiptoe” directly over the cocoon she 
raises the abdomen to a perpendicular position, at the same time lowering 
the ovipositor. Sometimes the ovipositor is lowered the entire distance 
free from the sheath, the latter remaining in line with the abdomen; 
but more frequently it is not released until it is at or below the horizontal, 
in which case the sheath bends downward, only the tip clasping the 
ovipositor. The sheath finally snaps back into position in line with the 
abdomen. 
When the lowering of the ovipositor is completed it lies along the 
ventral surface of the abdomen and extends down between the legs, while 
the tip of the abdomen is bent downward over the base of the ovipositor. 
The tip of the ovipositor, guided by the antennae, is placed against the 
surface of the cocoon. The antennae are then extended in front of the 
head and almost parallel with the surface on which the insect is stand¬ 
ing. The insect is now exactly analogous to a machine drill, the body 
and legs representing the machine and the ovipositor the drill. The 
bent-over tip of the abdomen is pressed against the base of the ovipositor, 
which bends forward against the ventral surface of the abdomen. With 
a more or less augurlike motion the ovipositor is forced through the 
cocoon. A few rapid jabs stir up the prospective host larva and it 
begins a desperate attack upon the ovipositor of its enemy, biting it and 
sometimes holding on with bulldog tenacity. In a number of cases the 
defense of the larva was so determined and powerful that the parasite 
was defeated and left the field minus a portion of her ovipositor, which 
had been bitten off by the larva. Usually, however, the parasite is suc¬ 
cessful in her efforts and finally thrusts her ovipositor into the larva, sting¬ 
ing it into insensibility. The stinging is usually repeated one or more 
times after intervals of rest. The subjugation of the host accomplished, 
the ovisitor is withdrawn from the host and thrust its entire length into 
the cocoon; then the parasite rests quietly for several minutes. In this 
position the abdomen is bent downward so that the tip is close to the 
base. The ovipositor sheath during all this time has retained its vertical 
position and is now in contact with the dorsal surface of the abdomen for 
about one-third of its length. In a few moments there begins a pulsation 
