139 
Although undoubtedly a good digger, Liris appears to rely 
somewhat upon pre-existing excavations for her nest; this is 
accordingly situated in the burrow of some small animal, deserted 
termite cavity, or other suitable place. Of the few nests that I 
have tried to dig out—until my enthusiasm was exhausted—all 
were profound affairs, perhaps three feet or more in depth, nor 
did I reach any of the wasp’s cells. 
The prey consists of crickets (Gryllidae), which are carried, 
usually in flight, beneath the wasp’s body. The victims were 
found to be of two species, commonly immature; in one instance 
observed the cricket proved so heavy a burden that Liris had to 
drag it along, venter down, to her burrow 150 feet away. The 
wasp plunges headfirst into the tunnel, carrying the cricket be- 
neath her, and this agility secures her prey in some measure 
against parasitic flies that often hang about the entrance to the 
nest. In one case Liris deposited her burden before the tunnel 
and made a short running dash at a watchful little grey tachinid 
parasite perched nearby on a blade of grass and tried to seize 
the fly in her mandibles. It evaded her, however, and so, after 
looking around for this enemy, the wasp resumed her storing. 
Solenopsis ¢ gemminata is another enemy to be reckoned w ith; 
such ants often occur about the burrow’s entrance, but the wasp’s 
cells are so far underground and in so moist a clay that they 
probably do not investigate to a dangerous depth. 
We sometimes see two or three female Liris using the same 
tunnel ; this gives the insect the appearance of being social, which, 
however, is not the case—far underground each wasp has her 
own cells. 
Liris, in common with some other sphecoid wasps, 1s pos- 
sessed of a very good eyesight, for, seeing you at a distance of 
25 feet, she will turn about to face you, and rearing the anterior 
part of her body well free of the ‘ground will sway it rapidly 
from side to side; this action may improve the facetted or 
mosaic vision by making the object of gaze a moving thing. 
In the dark recesses of the earth, however, Liris uses some other 
sense than vision. 


Tachytes banoensis Rohwer. 
Length 15 mm.; black; stout and bee-like ; tawny pubescence and 
silvery pile. 
I found two species of this genus at Los Banos, both stout in- 
sects, the larger a forest form possessing an exceedingly swift 
flight ; the smaller, common in the fields, much recalling 7. man- 
dibularis Patton of the United States. 
