24 
mud-dauber nests, etc.). Some mud nests are rainproof, others 
are not, and so the latter are built in sheltered places; hence we 
find the nests of mud-daubers (Sceliphronini) often placed under 
eaves of houses, against ceilings and in other safe positions. Some 
mud architects cover their cells with tree gum and lichens (Pseu- 
dagenia sp.), or with debris of various sort (Podium). Macro- 
meris uses a clay-like material of composite ners Some of 
the more specialized solitary wasps (Zethus, Zethusculus) 
use leaves or moss for nest building, and the very elongate 
shade-loving Stenogaster, material much like, though more 
frail than used by the paper-making hornets. It seems, then, 
that the higher wasps very commonly make use of superior 
building materials—superior in that less of it is required in the 
construction of a cell than in mud-daubing wasps, for example. 
Space may be economized, but time does not appear to be. 
REE GG: 
The cell made or the victim secured, the egg is the next se- 
quence in wasp life. The queen hornet (Vespa) may in her 
lifetime of some months lay several thousand eggs; this is all out 
of proportion to the egg-laying powers of solitary wasps. Zethus 
cyanopterus, a highly “specialized solitary wasp, probably lays 
fewer than a dozen eggs. Tachytes, a locust wasp less highly de- 
veloped, may produce as many as fifty, and some of the Scoliidae 
probably somewhat exceed this number. The wasp eggs that I 
have studied ranged from less than a millimeter in length 
(Methoca, Epyris) to seven millimeters (Chlorion, Macromeris). 
They are whitish or yellowish in color, two or more times longer 
than thick, usually slightly arched and commonly a little thicker 
at the head than at the posterior extremity. They may be placed 
near the food or on its surface.* The Psammocharidae glue their 
eggs near the base of the spider’s abdomen; most Sphecidae that 
attack grasshoppers, crickets or locusts affix theirs under or partly 
alongside the thorax, while Wethoca and Scolia sp. place their egg 
on the underside of the abdomen of the beetle grub. The head 
end of the egg is often against some tender spot of the victim’s 
anatomy. In those cases where the prey is paralyzed so as to 
be incapable of motion, the wasp’s egg may be only lightly glued 
to it (Methoca sp., Sceliphron, Scolia sp., in Scolia ‘the : egg stands 
on its head as it were) ; but where the prey largely recovers 
from the wasp’s sting, it is more securely glued (Tiphia, Methoca 
sp.) or placed in a well-protected position on y (Larra, Noto- 
* A great many of the non-aculeates insert their eggs in the food, whether it be 
plant or insect tissue. 
