162 
through human agency, and while there is still ample room in the 
cell for both mother and young, the former can no longer turn 
about therein, though she may attempt it, and so holding her 
wings close to the body, she backs in. 
The mature larva is quite stout, 
with the head rather small. When it 
is full-fed the mother closes up the 
mouth of the cell with leaf-bits, and 
while the inner side of this plug is 
rather crude, the outer face, which is 
slightly concave, is quite neat. The 
occupant can hardly be said to spin 
silk, though it elaborates a thin leath- 
ery partition (Fig. 94) some 6 mm., 
Fig. 94. Vertical section more or less, below the leaf partition 
through 4. cyanopterus and extends it slightly «down the cell 
cell containing a pupa and Ba Ope : 
showing the two dises Walls. The remainder of the walls is 
closing the c2ll, X 3/4. thinly coated with a larval juice of 
some sort. 
The pupa (Fig. 94) as it lies in its bent attitude is about 22 
mim. long. Ina rather advanced stage it is creamy yellow. 
When first freed from the pupal envelope, the adult is quite 
feeble in its humped attitude, and the wings not yet longitudinally 
folded, are bent apically. Some time must elapse before it ac- 
quires sufficient strength to bite its way to freedom through the 
two doors of the cell. 
Unless there is an emergence from another cell before the last 
is sealed up, the wasp may set about making another cell. She 
is therefore at first compelled to forego the comforts of a bed- 
chamber and spends the night out of doors, or partly so, using 
the commenced cell as a shelter. Otherwise a cell from which 
an adult has issued is cleared out for another brood. But prob- 
ably this process is not often repeated. 
The Zethus nest in the hibiscus bush I observed almost daily 
for a period of 127 days (December 24, 1916-April 22, 1917), 
and when I first found this nest, its proprietress had commenced 
to build the third of what proved to be a 4-celled nest, and so 
on December 24 it must have been at least two weeks old. 
The male wasp (Fig. 88) may linger about the nest for sev- 
eral Gays, and he was noted resting on or near it at night. But the 
progeny does not appear to stay around the old homestead. 
What enemies does the mother Zethus strive to guard 

