of her family, to
introduce herself as a parasite into the wasp's home, she resorts, they
tell us, to trickery and craftily dons her victim's livery. Once inside
the wasps' nest, she is taken for one of the inhabitants and attends
quietly to her business.

The simplicity of the wasp, duped by a very clumsy imitation of her
garb, and the depravity of the fly, concealing her identity under a
counterfeit presentment, exceed the limits of my credulity. The wasp
is not so silly nor the Volucella so clever as we are assured. If the
latter really meant to deceive the Wasp by her appearance, we must
admit that her disguise is none too successful. Yellow sashes round the
abdomen do not make a wasp. It would need more than that and, above all,
a slender figure and a nimble carriage; and the Volucella is thickset
and corpulent and sedate in her movements. Never will the wasp take that
unwieldy insect for one of her own kind. The difference is too great.

Poor Volucella, mimesis has not taught you enough. You ought--this is
the essential point--to have adopted a wasp's shape; and that you forgot
to do: you remained a fat fly, easily recognizable. Nevertheless, you
penetrate into the terrible cavern; you are able to stay there for a
long time, without danger, as the eggs profusely strewn on the wrapper
of the wasps' nest show. How do you set about it?

Let us, first of all, remember that the bumblebee fly does not enter the
enclosure in which the combs are heaped: she keeps to the outer surface
of the paper rampart and there lays her eggs. Let us, on the other hand,
recall the Polistes [a tree nesting wasp] placed in the company of the
wasps in my vivarium. Here of a surety is one who need not have recourse
to mimicry to find acceptance. She belongs to the guild, she is a wasp
herself. Any of us that had not the trained eye of the entomologist
would confuse the two species. Well, this stranger, as long as she does
not become too importunate, is quite readily tolerated by the caged
wasps. None seeks to pick a quarrel with her. She is even admitted to
the table, the strip of paper smeared with honey. But she is doomed if
she inadvertently sets foot upon the combs. Her costume, her shape, her
size, which tally almost exactly with the costume, shape and size of
the wasp, do not save her from her fate. She is at once recognized as a
stranger and attacked and slaughtered with the same vigor as the larvae
of the Hylotoma sawfly and the S