450 
DISCURSIVE NOTES ON THE 
The bearers of aposematic colouring may always be known 
by their bold demeanour : such an insect, instead of taking 
to flight, flaunts itself before you ; or, if unable to fly, will 
not get out of the way, but displays to the utmost the 
characteristic signal of inedibility or the possession of an 
efficient means of defence. 
Now, one family of the Fossors — although all the Fossors 
possess stings — is particularly interesting from the point of 
view of aposemes — namely, the Pompilidce. Their flashing 
blue-black bodies and wings, often associated with canary- 
yellow legs and antennse, make them most conspicuous as 
they sail by, or run over the ground ; their stings are very 
painful, and they advertise to the eye very plainly that they 
had better be left alone. To the eye, I said, but also to the 
ear ; and this is why the Pompilidce are particularly interesting, 
for they have evolved a method of appealing to more senses 
than one. Many of the larger species make such a loud rattling 
noise as they fly that one’s attention is irresistibly attracted — 
for they are often heard before they are seen — the noise being 
like the rattling of a particularly badly-made clockwork toy. 
It is obvious that to an edible insect such a noisy flight could 
be only the means of hastening its end : on the other hand, an 
enemy whose attention has been thus called to a particularly 
conspicuous insect leaves it severely alone. I have actually 
seen this with pet monkeys, tied up by a long cord : they have 
heard an approaching Pompilid, and watch it with suspicious 
care, and are very anxious not to interfere with it. I may say, 
in passing, that, for all their noise and unpleasant appearance, 
no Pompilid will interfere with you unless you interfere with 
it ; and you can securely watch a most ferocious-looking 
species that would give you cause to regret it if you seized 
hold of it. 
I know of no insects, save the Pompilidce, that make what 
may be termed an aposematic sound. Many beetles, and ants 
such as Megaponera foetens, and some Hemiptera, will make a 
stridulating noise when handled ; but this is more of the nature 
of an intimidating sound, and not an advertisement made 
continually while the insect goes about its ordinary affairs. 
It is rather interesting that the exact contrary may also 
