she allow the larva, her mess-mate, to take
advantage of the remains and afterwards to shift for itself as best it
can? But no: the Mason-bee's offspring must needs be stupidly sacrificed
on the top of provisions which will only grow mouldy and useless! I
should be reduced to the gloomy lucubrations of a Schopenhauer if I once
let myself begin on parasitism.

Such is a brief sketch of the two parasites of the Chalicodoma of the
Pebbles, true parasites, consumers of provisions hoarded on behalf
of others. Their crimes are not the bitterest tribulations of the
Mason-bee. If the first starves the Mason's grub to death, if the second
makes it perish in the egg, there are others who have a more pitiable
ending in store for the worker's family. When the Bee's grub, all plump
and fat and greasy, has finished its provisions and spun its cocoon
wherein to sleep the slumber akin to death, the necessary period of
preparation for its future life, these other enemies hasten to the nests
whose fortifications are powerless against their hideously ingenious
methods. Soon on the sleeper's body lies a nascent grub which feasts in
all security on the luscious fare. The traitors who attack the larvae
in their lethargy are three in number: an Anthrax, a Leucopsis and a
microscopic dagger-wearer. (Monodontomerus cupreus. For this and the
Anthrax, cf. "The Life of the Fly": chapters 2 and 3. The Leucopsis is
a Hymenopteron, the essay upon whom forms the concluding chapter of the
present volume.--Translator's Note.) Their story deserves to be told
without reticence; and I shall tell it later. For the moment, I merely
mention the names of the three exterminators.

The provisions are stolen, the egg is destroyed. The young grub dies of
hunger, the larva is devoured. Is that all? Not yet. The worker must
be exploited thoroughly, in her work as well as in her family. Here are
some now who covet her dwelling. When the Mason is constructing a new
edifice on a pebble, her almost constant presence is enough to keep the
aspirants to free lodgings at a distance; her strength and vigilance
overawe whoso would annex her masonry. If, in her absence, one greatly
daring thinks of visiting the building, the owner soon appears upon the
scene and ousts her with the most discouraging animosity. She has no
need then to fear the entrance of unwelcome tenants while the house is
new. But the Bee of the Pebbles also uses old dwellings for her laying,
as long as they