Packard.] 
INSECTS AS ARCHITECTS. 
319 
than the sand wasps. The different species of Crabro, with 
their large cubical heads, the Philanthus (Fig. 248) and 
Cerceris, refit old nail holes and tunnel rotten wood, filling 
their holes with aphides, caterpillars, beetles and spiders, etc. 
The European Pliilantlius apivorus has the unfortunate habit 
of provisioning its nest with honey bees ; so 
also with a species of Cerceris. The smaller, 
blackish species have the most interesting 
habits. In Europe, according to Prof. West- 
wood, the prey of a species of Oxybelus con¬ 
sists of flies, “which it has a peculiar mode Philanthus. 
of carrying by the hind legs the while it either opens the 
aperture of its burrow, or else forms a new one with its 
anterior pair.” 
A Trypoxylon wasp was detected in England frequenting 
the holes of a post preoccupied by a species of Odynerus, 
a solitary wasp closely allied to the social paper wasps, 
“ into which it conveyed a small round ball, or pellet, con¬ 
taining about fifty individuals of a species of Aphis ; this the 
Odynerus, upon her return, invariably turned out, flying out 
with it, held by her legs, to the distance of aboyt a foot from 
the aperture of her cell, where she hovered for a moment, 
and then let it fall; and this was constantly the case till the 
Trypoxylon had sufficient time to mortar up the orifice of 
the hole, and the Odynerus was then entirely excluded ; for 
although she would return to the spot repeatedly, she never 
endeavored to force the entrance, but flew off to seek another 
hole elsewhere.” The stems of the syringa, elder, black¬ 
berry and other pithy shrubs are also favorite nesting places 
of these wood wasps. Several species have been found by 
Mr. Angus nesting in the stems of the syringa; all their 
nests have a family resemblance, being simple tunnels, with¬ 
out any pretensions to architectural skill. 
The stems of the blackberry or syringa are often tenanted 
by the little green Ceratina bee. Figure 249 represents a 
31 
Fig. 248. 
