23 
well has been found by Bridwell (1918) parasitizing in its cocoon 
the larva of Car yoborus gonagra F abricius, one of the so-called 
bean-weevils. The genus Epyris, comprising some of the larger 
Bethylidae, prey on the larvae of tenebrionid beetles, which they 
often sting when underground. But where the victim is subdued 
on the surface of the ground this wasp proves equal to the emer- 
gency and buries it. So, too, with the Scoliidae, an extensive 
and useful family of thick-set wasps that prey on lamellicorn 
beetle grubs. The latter usually feed in decayed wood, compost 
heaps or underground at roots, and are there sought and para- 
sitized by the wasps and left without further ado. But there 
are a few records of Scoliids also burying these grubs. (Forbes, 
1908, p. 159.) The prey of some wasps of more advanced type 
live in well-defined burrows which are utilized as nest holes by 
these wasps. For example, Methoca, a genus placed sometimes 
in the Mutillidae, but more often with the Thynnidae, parasitizes 
the larvae of tiger-beetles, and if these, in their struggle for life, 
crawl out of their retreat, they are afterwards pulled in and 
buried. The Mutillidae or ‘velvet ants” mostly enter the nests 
of bees and other wasps and ees their young. Some of the 
Psammocharidae, also known as Pompilidae or “spider wasps,” 
use the burrows of their victims as a cell for their young. The 
Ampulicidae or cockroach hunters drag their subdued prey into 
some hole or other shelter. But a ‘large proportion of the 
ground wasps, sometimes also called “Fossores” or “digger 
wasps, are more advanced in development and thus fitted to dig 
burrows or construct other definite nests, of which there exist 
a great variety. For instance, Tachysphex and Priononyx, 
sphecid wasps, both hunters of Orthoptera (grasshoppers, 
roaches, etc.), quickly excavate and store their short burrows, 
which terminate in a single cell or enlargement. Liris, Cerceris 
and Tachytes are more extensive diggers and may require a 
week or more in which to dig and provision their tunnels of sev- 
eral cells.t. Many wasps are architects, building’ nests above 
ground ; fewer combine their architecture with burrows. Thus we 
have the mud nests of many Sphecidae, Pompilidae and Eument- 
dae, and then there are many Odynerus and some Masarids which 
dig holes, divide off the cells with a partition of clay, and with the 
same material build a delicate tube over the entrance to the bur- 
row. Trypoxrylon and some Pseudagenia, spider-wasps, fre- 
quently divide off cells in pre-existing hollows (bamboos, reeds, 

y The order of business in wasp life—mainly nesting activities—is not always 
the same. We have some species, as Priononyx, Dolichurus and some Psammo- 
charidae, which first secure their provisions and then dig a hole, while others, 
probably the majority, make their nests and then search for victims. 
