FOSSOBIAL HYMENOPTER A 
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prey she is in need of, be it caterpillar or a grasshopper, cricket, 
or other member of the Orthoptera. She hurries about, 
antennae vibrating, wings flicking, examining every likely 
locality, until suddenly — Pounce ! She has found it ; there 
is a brief rough and tumble, and in a moment the prey has 
been stung, and the successful huntress starts to carry it back. 
This journey has, in one case, already been described. On 
arrival at the burrow, the Sphegid puts down her prey, dis- 
closes the mouth of the tunnel, and goes down to see that 
all is well, as has been described. This is the opportunity 
for which her enemies are waiting to hurry down and lay their 
own eggs on the prey which they do not get themselves. 
The prey having been safely bestowed, and an egg laid upon 
it, the Sphegid proceeds to close the burrow. Standing with 
her head away from it, she scratches loose earth backwards, 
with sure aim, so that it falls into the hole. But a mere 
accumulation of loose earth is not enough — it would soon 
sink and leave a hollow, revealing the existence of the burrow : 
it must be pressed down. 
This is an extremely interesting part of the performance, 
for reasons that will be seen later when the work of the Pom- 
pilidce is described. The Sphegid uses the front of her broad 
head as a battering-ram, and, getting a firm hold of the sides 
of the burrow with her last two pairs of limbs, launches herself 
down the burrow, pressing down the loose earth to the accom- 
paniment of a buzzing sound. Occasionally a small bit of 
stone is picked up in her mandibles, put down the burrow, and 
rammed home in the same way ; finally, loose earth is scratched 
over the surface, and, having thoroughly satisfied herself that 
the surface of the ground gives no indication of the treasure 
beneath, the Sphegid flies off to refresh herself on a neighbouring 
flower before repeating the whole laborious process. 
Lastly, mention must be made of the large family 
Pompilidce, whose habits in all essentials are similar to those 
just described. These Fossors have not the very long, narrow 
pedicle to the abdomen so often seen in Sphegidce and true 
wasps such as Belonogaster, and their legs are longer in pro- 
portion ; their clockwork flight and aposematic colouration 
have already been mentioned. So far as I know, they confine 
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