To illustrate the methods of those who batten on others' goods, the
plunderers who know no rest till they have wrought the destruction of
the worker, it would be difficult to find a better instance than the
tribulations suffered by the Chalicodoma of the Walls. The Mason
who builds on the pebbles may fairly boast of being an industrious
workwoman. Throughout the month of May, we see her black squads, in the
full heat of the sun, digging with busy teeth in the mortar-quarry of
the road hard by. So great is her zeal that she hardly moves out of
the way of the passer-by; more than one allows herself to be crushed
underfoot, absorbed as she is in collecting her cement.
The hardest and driest spots, which still retain the compactness
imparted by the steam-roller, are the favourite veins; and the work of
making the pellet is slow and painful. It is scraped up atom by atom;
and, by means of saliva, turned into mortar then and there. When it is
all well kneaded and there is enough to make a load, the Mason sets off
with an impetuous flight, in a straight line, and makes for her pebble,
a few hundred paces away. The trowel of fresh mortar is soon spent,
either in adding another storey to the turret-shaped edifice, or in
cementing into the wall lumps of gravel that give it greater solidity.
The journeys in search of cement are renewed until the structure attains
the regulation height. Without a moment's rest, the Bee returns a
hundred times to the stone-yard, always to the one spot recognized as
excellent.
The victuals are now collected: honey and flower-dust. If there is a
pink carpet of sainfoin anywhere in the neighbourhood, 'tis there that
the Mason goes plundering by preference, though it cost her a four
hundred yards' journey every time. Her crop swells with honeyed
exudations, her belly is floured with pollen. Back to the cell, which
slowly fills; and back straightway to the harvest-field. And all day
long, with not a sign of weariness, the same activity is maintained as
long as the sun is high enough. When it is late, if the house is not
yet closed, the Bee retires to her cell to spend the night there,
head downwards, tip of her abdomen outside, a habit foreign to the
Chalicodoma of the Sheds. Then and then alone the Mason rests; but it
is a rest that is in a sense equivalent to work, for, thus placed, she
blocks the entrance to the honey-store and defends her treasure against
twilight or night marauders.
Being anxious to form some estimate of the total distance covered by the
Bee in the construction and provisioning of a single cell, I counted the
number of steps from a nest to the road where the mortar was mixed and
from the same nest to the sainfoin-field where the harvest was gathered.
I took such note as my patience permitted of the journeys made in both
directions; and, completing these data with a comparison between the
work done and that which remained to do, I arrived at nine and a half
miles as the result of the total travelling. Of course, I give this
figure only as a rough calculation; greater precision would have
demanded more perseverance than I can boast.
Such as it is, the result, which is probably under the actual figure in
many cases, is of a kind that gives us a vivid idea of the Mason-bee's
activity. The complete nest will comprise about fifteen cells. Moreover,
the heap of cells will be coated at the end with a layer of cement a
good finger's-breadth thick. This massive fortification, which is less
finished than the rest of the work but more expensive in materials,
represents perhaps in itself one half of the complete task, so that,
to establish her dome, Chalicodoma muraria, coming and going across the
arid table-land, traverses altogether a distance of 275 miles, which
is nearly half of the greatest dimension of France from north to south.
Afterwards, when, worn out with all this fatigue, the Bee retires to a
hiding-place to languish in solitude and die, she is surely entitled to
say:
'I have laboured, I have done my duty!'
Yes, certainly, the Mason has toiled with a vengeance. To ensure the
future of her offspring, she has spent her own life without reserve, her
long life of five or six weeks' duration; and now she breathes her last,
contented because everything is in order in the beloved house: copious
rations of the first quality; a shelter against the winter frosts;
ramparts against incursions of the enemy. Everything is in order,
at least so she thinks; but, alas, what a mistake the poor mother is
making! Here the hateful fatality stands revealed, aspera fata, which
ruins the producer to provide a living for the drone; here we see the
stupid and ferocious law that sacrifices the worker for the idler's
benefit. What have we done, we and the insects, to be ground with
sovran indifference under the mill-stone of such wretchedness? Oh, what
terrible, what heart-rending questions the Mason-bee's misfortunes would
bring to my lips, if I gave free scope to my sombre thoughts! But let
us avoid these useless whys and keep within the province of the mere
recorder.
There are some ten of them plotting the ruin of the peaceable and
industrious Bee; and I do not know them all. Each has her own tricks,
her own art of injury, her own exterminating tactics, so that no part of
the Mason's work may escape destruction. Some seize upon the victuals,
others feed on the larvae, others again convert the dwelling to their
own use. Everything has to submit: cell, provisions, scarce-weaned
nurselings.
The stealers of food are the Stelis-wasp (Stelis nasuta) and the
Dioxys-bee (Dioxys cincta). I have already said how, in the Mason's
absence, the Stelis perforates the dome of cell after cell, lays her
eggs there and afterwards repairs the breach with a mortar made of red
earth, which at once betrays the parasite's presence to a watchful eye.
The Stelis, who is much smaller than the Chalicodoma, finds enough food
in a single cell for the rearing of several of her grubs. The mother
lays a number of eggs, which I have seen vary between the extremes of
two and twelve, on the surface, next to the Mason's egg, which itself
undergoes no outrage whatever.
Things do not go so badly at first. The feasters swim--it is the
only word--in the midst of plenty; they eat and digest like brothers.
Presently, times become hard for the hostess' son; the food decreases,
dearth sets in; and at length not an atom remains, although the Mason's
larva has attained at most a quarter of its growth. The others, more
expeditious feeders, have exhausted the victuals long before the victim
has finished his normal repast. The swindled grub shrivels up and dies,
while the gorged larvae of the Stelis begin to spin their strong little
brown cocoons, pressed close together and lumped into one mass, so as
to make the best use of the scanty space in the crowded dwelling. Should
you inspect the cell later, you will find, between the heaped cocoons
on the wall, a little dried-up corpse. It is the larva that was such an
object of care to the mother Mason. The efforts of the most laborious of
lives have ended in this lamentable relic. It has happened to me just
as often, when examining the secrets of the cell which is at once cradle
and tomb, not to come upon the deceased grub at all. I picture the
Stelis, before laying her own eggs, destroying the Chalicodoma's egg
and eating it, as the Osmiae do among themselves; or I picture the dying
thing, an irksome mass for the numerous spinners at work in a narrow
habitation, being cut to pieces to make room for the medley of cocoons.
But to so many deeds of darkness I would not like to add another by an
oversight; and I prefer to admit that I failed to perceive the grub that
died of hunger.
Let us now show up the Dioxys. At the time when the work of construction
is in progress, she is an impudent visitor of the nests, exploiting with
the same effrontery the enormous cities of the Mason-bee of the Sheds
and the solitary cupolas of the Mason-bee of the Pebbles. An innumerable
population, coming and going, humming and buzzing, strikes her with no
awe. On the tiles hanging from the walls of my porch I see her, with
her red scarf round her body, stalking with sublime assurance over the
ridged expanse of nests. Her black schemes leave the swarm profoundly
indifferent; not one of the workers dreams of chasing her off, unless
she should come bothering too closely. Even then, all that happens is
a few signs of impatience on the part of the hustled Bee. There is no
serious excitement, no eager pursuits such as the presence of a mortal
enemy might lead us to suspect. They are there in their thousands,
each armed with her dagger; any one of them is capable of slaying the
traitress; and not one attacks her. The danger is not suspected.
Meanwhile, she inspects the workyard, moves freely among the ranks of
the Masons and bides her time. If the owner be absent, I see her diving
into a cell, coming out again a moment later with her mouth smeared with
pollen. She has been to try the provisions. A dainty connoisseur, she
goes from one store to another, taking a mouthful of honey. Is it a
tithe for her personal maintenance, or a sample tested for the benefit
of her coming grub? I should not like to say. What I do know is that,
after a certain number of these tastings, I catch her stopping in a
cell, with her abdomen at the bottom and her head at the orifice. This
is the moment of laying, unless I am much mistaken.
When the parasite is gone, I inspect the home. I see nothing abnormal
on the surface of the mass. The sharper eye of the owner, when she gets
back, sees nothing either, for she continues the victualling without
betraying the least uneasiness. A strange egg, laid on the provisions,
would not escape her. I know how clean she keeps her warehouse; I know
how scrupulously she casts out anything introduced by my agency: an egg
that is not hers, a bit of straw, a grain of dust. So, according to
my evidence and that of the Chalicodoma, which is more conclusive, the
Dioxys's egg, if it is really laid then, is not placed on the surface.
I suspect, without having yet verified my suspicion--and I reproach
myself for the neglect--I suspect that the egg is buried in the heap of
pollen-dust. When I see the Dioxys come out of a cell with her mouth
all over yellow flour, perhaps she has been surveying the ground and
preparing a hiding-place for her egg. What I take for a mere tasting
might well be a more serious act. Thus concealed, the egg escapes the
eagle eye of the Bee, whereas, if left uncovered, it would inevitably
perish, would be flung on the rubbish heap at once by the owner of
the nest. When the Spotted Sapyga lays her egg on that of the
Bramble-dwelling Osmia, she does the deed under cover of darkness,
in the gloom of a deep well to which not the least ray of light can
penetrate; and the mother, returning with her pellet of green putty
to build the closing partition, does not see the usurping germ and is
ignorant of the danger. But here everything happens in broad daylight;
and this demands more cunning in the method of installation.
Besides, it is the one favourable moment for the Dioxys. If she waits
for the Mason-bee to lay, it is too late, for the parasite is not able
to break down doors, as the Stelis does. As soon as her egg is laid, the
Mason-bee of the Sheds comes out of her cell and at once turns round and
proceeds to close it up with the pellet of mortar which she holds ready
in her mandibles. The material is employed with such method that the
actual sealing is done in a moment: the other pellets, the object of
repeated journeys, will serve merely to increase the thickness of the
lid. The chamber is inaccessible to the Dioxys from the first touch of
the trowel. Hence it is absolutely necessary for her to see to her
egg before the Mason-bee of the Sheds has disposed of hers and no less
necessary to conceal it from the Mason's watchful eye.
The difficulties are not so great in the nests of the Mason-bee of the
Pebbles. After this Bee has laid her egg, she leaves it for a time to go
in search of the cement needed for closing the cell; or, if she already
holds a pellet in her mandibles, this is not enough to seal it properly,
as the orifice is larger. More pellets are needed to wall up the
entrance entirely. The Dioxys would have time to strike her blow during
the mother's absences; but everything seems to suggest that she behaves
on the pebbles as she does on the tiles. She steals a march by hiding
the egg in the mass of pollen and honey.
What becomes of the Mason's egg confined in the same cell with the egg
of the Dioxys? In vain have I opened nests at every season; I have never
found a vestige of the egg nor of the grub of either Chalicodoma. The
Dioxys, whether as a larva on the honey, or enclosed in its cocoon,
or as the perfect insect, was always alone. The rival had disappeared
without a trace. A suspicion thereupon suggests itself; and the facts
are so compelling that the suspicion is almost equal to a certainty. The
parasitic grub, which hatches earlier than the other, emerges from its
hiding-place, from the midst of the honey, comes to the surface and,
with its first bite, destroys the egg of the Mason-bee, as the Sapyga
does the egg of the Osmia. It is an odious, but a supremely efficacious
method. Nor must we cry out too loudly against such foul play on the
part of a new born infant: we shall meet with even more heinous tactics
later. The criminal records of life are full of these horrors which we
dare not search too deeply. An infinitesimal creature, a barely-visible
grub, with the swaddling-clothes of its egg still clinging to it, is led
by instinct, at its first inspiration, to exterminate whatever is in its
way.
So the Mason's egg is exterminated. Was it really necessary in the
Dioxys' interest? Not in the least. The hoard of provisions is too large
for its requirements in a cell of the Chalicodoma of the Sheds; how
much more so in a cell of the Chalicodoma of the Pebbles! She eats not
a half, hardly a third of it. The rest remains as it was, untouched. We
see here, in the destruction of the Mason's egg, a flagrant waste which
aggravates the crime. Hunger excuses many things; for lack of food, the
survivors on the raft of the Medusa indulged in a little cannibalism;
but here there is enough food and to spare. When there is more than she
needs, what earthly motive impels the Dioxys to destroy a rival in
the germ stage? Why cannot 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 are not too much dilapidated. In the early stages of
the work, neighbours compete for these with an eagerness which shows
the value attached to them. Face to face, at times with their mandibles
interlocked, now both rising into the air, now coming down again, then
touching ground and rolling over each other, next flying up again, for
hours on end they will wage battle for the property at issue.
A ready-made nest, a family heirloom which needs but a little restoring,
is a precious thing for the Mason, ever sparing of her time. We find so
many of the old homes repaired and restocked that I suspect the Bee of
laying new foundations only when there are no secondhand nests to be
had. To have the chambers of a dome occupied by a stranger therefore
means a serious privation.
Now several Bees, however industrious in gathering honey, building
party-walls and contriving receptacles for provisions, are less clever
at preparing the resorts in which the cells are to be stacked. The
abandoned chambers of the Chalicodoma, now larger than they were
originally, through the addition of the hall of exit, are first-rate
acquisitions for them. The great thing is to occupy these chambers
first, for here possession is nine parts of the law. Once established,
the Mason is not disturbed in her home, while she, in her turn, does not
disturb the stranger who has settled down before her in an old nest,
the patrimony of her family. The disinherited one leaves the Bohemian to
enjoy the ruined manor in peace and goes to another pebble to establish
herself at fresh expense.
In the first rank of these free tenants, I will place an Osmia (Osmia
cyanoxantha, PEREZ) and a Megachile, or Leaf-cutting Bee (Megachile
apicalis, SPIN.) (Cf. "Bramble-dwellers and Others": chapter
8.--Translator's Note.), both of whom work in May, at the same time as
the Mason, while both are small enough to lodge from five to eight
cells in a single chamber of the Chalicodoma, a chamber increased by
the addition of an outer hall. The Osmia subdivides this space into
very irregular compartments by means of slanting, upright or curved
partitions, subject to the dictates of space. There is no art,
consequently, in the accumulation of little cells; the architect's
only task is to use the breadth at her disposal in a frugal manner. The
material employed for the partitions is a green, vegetable putty, which
the Osmia must obtain by chewing the shredded leaves of a plant whose
nature is still uncertain. The same green paste serves for the thick
plug that closes the abode. But in this case the insect does not use it
unadulterated. To give greater power of resistance to the work, it mixes
a number of bits of gravel with the vegetable cement. These materials,
which are easily picked up, are lavishly employed, as though the mother
feared lest she should not fortify sufficiently the entrance to her
dwelling. They form a sort of coarse stucco, on the more or less smooth
cupola of the Chalicodoma; and this unevenness, as well as the green
colouring of its mortar of masticated leaves, at once betrays the
Osmia's nest. In course of time, under the prolonged action of the air,
the vegetable putty turns brown and assumes a dead-leaf tint, especially
on the outside of the plug; and it would then be difficult for any one
who had not seen them when freshly made to recognize their nature.
The old nests on the pebbles seem to suit other Osmiae. My notes
mention Osmia Morawitzi, PEREZ, and Osmia cyanea, KIRB., as having been
recognized in these dwellings, although they are not very assiduous
visitors. Lastly, to complete the enumeration of the Bees known to me
as making their homes in the Mason's cupolas, I must add Megachile
apicalis, who piles in each cell a half-dozen or more honey-pots
constructed with disks cut from the leaves of the wild rose, and an
Anthidium whose species I cannot state, having seen nothing of her but
her white cotton sacks.
The Mason-bee of the Sheds, on the other hand, supplies free lodgings
to two species of Osmiae, Osmia tricornis, LATR., and Osmia Latreillii,
SPIN., both of whom are quite common. The Three-horned Osmia frequents
by preference the habitations of the Bees that build their nests
in populous colonies, such as the Chalicodoma of the Sheds and the
Hairy-footed Anthophora. Latreille's Osmia is nearly always found with
the Three-horned Osmia at the Chalicodoma's.
The real builder of the city and the exploiter of the labour of others
work together, at the same period, form a common swarm and live in
perfect harmony, each Bee of the two species attending to her business
in peace. They share and share alike, as though by tacit agreement. Is
the Osmia discreet enough not to put upon the good-natured Mason and
to utilize only abandoned passages and waste cells? Or does she take
possession of the home of which the real owners could themselves have
made use? I lean in favour of usurpation, for it is not rare to see the
Chalicodoma of the Sheds clearing out old cells and using them as does
her sister of the Pebbles. Be this as it may, all this little busy world
lives without strife, some building anew, others dividing up the old
dwelling.
Those Osmiae, on the contrary, who are the self-invited guests of the
Mason-bee of the Pebbles are the sole occupants of the dome. The cause
of this isolation lies in the unsociable temper of the proprietress. The
old nest does not suit her from the moment that she sees it occupied
by another. Instead of going shares, she prefers to seek elsewhere a
dwelling where she can work in solitude. Her gracious surrender of a
most excellent lodging in favour of a stranger who would be incapable
of offering the least resistance if a dispute arose proves the great
immunity enjoyed by the Osmia in the home of the worker whom she
exploits. The common and peaceful swarming of the Mason-bee of the Sheds
and the two cell-borrowing Osmiae proves it in a still more positive
fashion. There is never a fight for the acquisition of another's goods
or the defence of one's own property; never a brawl between Osmiae and
Chalicodomae. Robber and robbed live on the most neighbourly terms. The
Osmia considers herself at home; and the other does nothing to undeceive
her. If the parasites, so deadly to the workers, move about in their
very ranks with impunity, without arousing the faintest excitement, an
equally complete indifference must be shown by the dispossessed owners
to the presence of the usurpers in their old homes. I should be greatly
put to it if I were asked to reconcile this calmness on the part of the
expropriated one with the ruthless competition that is said to sway the
world. Fashioned so as to instal herself in the Mason's property, the
Osmia meets with a peaceful reception from her. My feeble eyes can see
no further.
I have named the provision-thieves, the grub-murderers and the
house-grabbers who levy tribute on the Mason-bee. Does that end the
list? Not at all. The old nests are cities of the dead. They contain
Bees who, on achieving the perfect state, were unable to open the
exit-door through the cement and who withered in their cells; they
contain dead larvae, turned into black, brittle cylinders; untouched
provisions, both mouldy and fresh, on which the egg has come to grief;
tattered cocoons; shreds of skins; relics of the transformation.
If we remove the nest of the Chalicodoma of the Sheds from its tile--a
nest sometimes quite eight inches thick--we find live inhabitants
only in a thin outer layer. All the remainder, the catacombs of past
generations, is but a horrible heap of dead, shrivelled, ruined,
decomposed things. Into this sub-stratum of the ancient city the
unreleased Bees, the untransformed larvae fall as dust; here the
honey-stores of old go sour, here the uneaten provisions are reduced to
mould.
Three undertakers, all members of the Beetle tribe, a Clerus, a Ptinus
and an Anthrenus, batten on these remains. The larvae of the Anthrenus
and the Ptinus gnaw the ashes of the corpses; the larva of the Clerus,
with the black head and the rest of its body a pretty pink, appeared to
me to be breaking into the old jam-pots filled with rancid honey. The
perfect insect itself, garbed in vermilion with blue ornaments, is
fairly common on the surface of the clay slabs during the working
season, strolling leisurely through the yard to taste here and there the
drops of honey oozing from some cracked pot. Notwithstanding his showy
livery, so unlike the workers' sombre frieze, the Chalicodomae leave him
in peace, as though they recognized in him the scavenger whose duty it
is to keep the sewers wholesome.
Ravaged by the passing years, the Mason's home at last falls into ruin
and becomes a hovel. Exposed as it is to the direct action of wind and
weather, the dome built upon a pebble chips and cracks. To repair it
would be too irksome, nor would that restore the original solidity of
the shaky foundation. Better protected by the covering of a roof, the
city of the sheds resists longer, without however escaping eventual
decay. The storeys which each generation adds to those in which it was
born increase the thickness and the weight of the edifice in alarming
proportions. The moisture of the tile filters into the oldest layers,
wrecks the foundations and threatens the nest with a speedy fall. It is
time to abandon for good the house with its cracks and rents.
Thereupon the crumbling apartments, on the pebble as well as on the
tile, become the home of a camp of gypsies who are not particular where
they find a shelter. The shapeless hovel, reduced to a fragment of a
wall, finds occupants, for the Mason's work must be exploited to the
utmost limits of possibility. In the blind alleys, all that remains of
the former cells, Spiders weave a white-satin screen, behind which they
lie in wait for the passing game. In nooks which they repair in
summary fashion with earthen embankments or clay partitions, Hunting
Wasps--Pompili and Tripoxyla--store up small members of the Spider
tribe, including sometimes the Weaving Spiders who live in the same
ruins.
I have said nothing yet of the Chalicodoma of the Shrubs. My silence
is not due to negligence, but to the circumstance that I am almost
destitute of facts relating to her parasites. Of the many nests which
I have opened in order to study their inhabitants, only one so far has
been invaded by strangers. This nest, the size of a large walnut, was
fixed on a pomegranate-branch. It comprised eight cells, of which seven
were occupied by the Chalicodoma, and the eighth by a little Chalcis,
the plague of a whole host of the Bee-tribe. Apart from this instance,
which was not a very serious case, I have seen nothing. In those
aerial nests, swinging at the end of a twig, not a Dioxys, a Stelis,
an Anthrax, a Leucopsis, those dread ravagers of the other two Masons;
never any Osmiae, Megachiles or Anthidia, those lodgers in the old
buildings.
The absence of the latter is easily explained. The Chalicodoma's masonry
does not last long on its frail support. The winter winds, when the
shelter of the foliage has disappeared, must easily break the twig,
which is little thicker than a straw and liable to give way by reason of
its heavy burden. Threatened with an early fall, if it is not already on
the ground, last year's dwelling is not restored to serve the needs of
the present generation. The same nest does not serve twice; and this
does away with the Osmiae and with their rivals in the art of utilizing
old cells.
The elucidation of this point does not remove the obscurity of the next.
I can see nothing to account for the absence or at least the extreme
rareness of usurpers of provisions and consumers of grubs, both of whom
are very indifferent to the new or old conditions of the nest, so long
as the cells are well stocked. Can it be that the lofty position of the
edifice and the shaky support of the twig arouse distrust in the Dioxys
and other malefactors? For lack of a better explanation, I will leave it
at that.
If my idea is not an empty fancy, we must admit that the Chalicodoma of
the Shrubs was singularly well-inspired in building in mid-air. You have
seen of what misfortunes the other two are victims. If I take a census
of the population of a tile, many a time I find the Dioxys and the
Mason-bee in almost equal proportions. The parasite has wiped out
half the colony. To complete the disaster, it is not unusual for the
grub-eaters, the Leucopsis and her rival, the pygmy Chalcis, to have
decimated the other half. I say nothing of Anthrax sinuata, whom I
sometimes see coming from the nests of the Chalicodoma of the Sheds; her
larva preys on the Three-horned Osmia, the Mason-bee's visitor.
All solitary though she be on her boulder, which would seem the proper
thing to keep away exploiters, the scourge of dense populations, the
Chalicodoma of the Pebbles is no less sorely tried. My notes abound in
cases such as the following: of the nine cells in one dome, three are
occupied by the Anthrax, two by the Leucopsis, two by the Stelis, one
by the Chalcis and the ninth by the Mason. It is as though the four
miscreants had joined forces for the massacre: the whole of the Bee's
family has disappeared, all but one young mother saved from the disaster
by her position in the centre of the citadel. I have sometimes stuffed
my pockets with nests removed from their pebbles without finding a
single one that has not been violated by one or other of the malefactors
and oftener still by several of them at a time. It is almost an event
for me to find a nest intact. After these funereal records, I am haunted
by a gloomy thought: the weal of one means the woe of another.