73 
or urged it, but becoming impatient at its poor response, she 
backed down into the burrow at an opportune moment and, 
always facing her prey, stung it instantly and rushed out. The 
act of entering the hole appeared deliberate if quick, and the 
stinging was done with a sort of jumbling speed. 
October 7, 8 a. m.: A fresh beetle larva was placed in a 
shallow hole in the tumbler which contained the larger Methoca. 
The latter vibrated her antennae before it, but the larva was 
uncomfortable in its short and well-illuminated tunnel and started 
to crawl out. The wasp, as if standing on her hind legs, bent 
her abdomen forward so as to have her sting in position, much as 
do braconid parasites, etc., in stinging caterpillars, and stung the 
cicindelid during a vigorous scuffle of less than a second while 
on the surface of the ground. I replaced the helpless larva in the 
tunnel, but Methoca, her possessive instinct at its height, would 
not be driven away from her prey, which I gently essayed to do 
with a pair of forceps. By the way of further experiment | 
grasped the jaws of the larva with the forceps and, pulling up, 
caused it to move; at this, Methoca again curled her abdomen as 
if to sting, but she evidently felt sure of her previous work and 
soon walked about her booty. 
October 9, p. m.: A tiger-beetle larva had plugged up its 
burrow for one and one-half inches and rested at the bottom of 
the tumbler. None the less, the smaller wasp located this plugged 
tunnel and, after a little preliminary caution, commenced digging 
out a passage through and in it. But being such a slender insect, 
with legs hardly fitted for digging, she accomplished little, pene- 
trating a half inch in about twenty minutes. She soon aban- 
doned the work. 
October 14: The larger wasp slid down into a burrow and 
alongside the cicindelid larva, which promptly seized her amid- 
ships in her jaws, but was immediately and fatally stung for her 
pains. ‘The released wasp was apparently unhurt. 
October 23, p. m.: The larger wasp became engrossed in a 
recently inserted fee and leaned inquiringly over its burrow. 
She grew impatient at the inactivity of the occupant, and at a 
movement from the latter deliberately lowered herself down, 
tail-first. At her entry the larva retreated further down, but 
Methoca appeared to be doing her best to place herself in a posi- 
tion to be seized. I was not able to clearly witness the ensuing 
struggle, but the doomed larva squirmed about violently and 
took many minutes to succumb. 
October 24, a. m.: The larger wasp attacked a larva, which 
for a brief instant held her in its sickle-like jaws. The released 
