153 
tect is a good deal longer than the biggest cell dimension. We 
may first see her perched in the muddy road gathering moist 
clay in her month, and when she has accumulated a ball as large 
or larger than her head, she takes wing, holding her load in her 
mouth and probably also partly supported by the base of her 
forelegs. In building the cell walls she uses her long mandi- 
bles and her antennae for in- 
side, and her two forelegs for 
outside work, the antennae 
seeming to be measurers of 
some kind. The forelegs are 
opposers to the trowel work 
of the mandibles, and spread- 
ers and distributers of the 
large lump of mud.* She tops 
off the cell with a narrow cir- 
cular lip, which she makes 
flare out by flattening down 
on all sides with her mouth 
parts. Two hours and three- 
quarters were required to 
build the second cell to her 
nest. As soon as it was com- 
pleted the wasp walked on top 
of the cell and proceeded to 
livanvecouin at. “ihe aper- 
ture of the jug was but 3mm. Fig. 82. Ewmenes curvata, 2, X 2. 
in diameter, while the bulbous 
portion of the wasp’s abdomen measured very much more, but, 
thanks to the flaring mouth of the cell, Ewmenes, by sitting on top 
of the mouth and bending her body somewhat, was able to insert 
it perhaps 3 mm. into this opening and to suspend her egg to the 
ceiling of the cell. 
The next job on hand is the immediate gathering of caterpil- 
lars and storing them in the cell. She flies to the field or forest 
and finally secures a suitable larva, occasionally one of the Noc- 
tuidae or Notodontidae, but more commonly a measuring worm 
(Geometridae). One nest of this species contained several larvae 

* This mode of work is very different from that used by the architect spider 
wasps (Pseudagenia, etc.). Eumenes deposits her ball of mud all at once and 
uses her mandibles and forelegs to manipuate it; Pseudagenia usually uses only 
a portion of her load of mud at one time, spreading this on with the dorsal tip 
of the abdomen (Fig. 45), and is constantly working up the mud in her jaws, 
doing the mixing and spreading simultaneously. 
