male _Anthophora_ comes within reach, two
or three of them catch hold of him and climb on to his thorax. They
maintain themselves there by clinging to the hairs. At the moment of
fertilisation the male, thus burdened, comes in contact with the
female; the coleopterous larvae then pass on to her, so that, according
to Fabre's expression, the meeting of the sexes brings death and life
to the eggs at the same time. Henceforth fixed on this laying insect,
the little _Sitaris_ remain quiet, and have only to wait; their future
is assured. The _Anthophora_ has made her chambers, and with the
greatest care has filled each of them with honey. Then in the midst
she deposits an egg, which remains floating on the surface like a
little boat; when her task is accomplished, the mother passes to a new
cell to confide to it another of her descendants. During this time the
parasite larva hastily descends the abdominal hairs and allows itself
to fall on the egg of the _Anthophora_, to be then borne upon it as
upon a raft; its fall must take place at the precise instant which
will enable it to embark without falling into the honey, in which just
now it would be glued fast, and perish. This series of circumstances
results only in the introduction of a single _Sitaris_ into a chamber;
the moment which must be profited by is too short for many of them to
seize. If the female _Anthophora_ carries others hidden in her hairs,
they are obliged to await a new hatching to let themselves glide off.
Thus enclosed with the egg of the _Anthophora_ and its provision of
honey, the larva has no other rival to fear, and may alone utilise the
whole store. This parasitism has to such an extent become a habit with
the species, that the larva's organisation has become modified by it.
At the moment when it falls into the cell it cannot feed on honey. It
is indispensable for its development that it should first devour the
egg on which it floats; it can at this period be nourished by no other
food. In acting in this way it also frees itself from a voracious
being who would require much food. This first repast lasts about eight
days, at the end of which it undergoes a moult, takes another form,
and begins to float on the honey, gradually devouring it, for at this
stage it becomes able to assimilate honey. Slowly its development is
completed, with extremely interesting details with which we need not
now concern ourselves. The larva of _Sitaris_ is then in conditions