sufficient space for it out of the wood with her jaws. We say _her_,
because the task in this instance, as in most others of solitary bees
and wasps, devolves solely upon the female, the male taking no concern
in the affair, and probably being altogether ignorant that such a work
is going forward. It is, at least, certain that the male is never
seen giving his assistance, and he seldom, if ever, approaches the
neighbourhood. The female carpenter-bee has a task to perform no less
arduous than the mason-bee; for though the wood may be tolerably soft,
she can only cut out a very small portion at a time. The successive
portions which she gnaws off may be readily ascertained by an observer,
as she carries them away from the place. In giving the history of a
mason-wasp (_Odynerus_), at page 22, we remarked the care with which
she carried to a distance little fragments of brick, which she
detached in the progress of excavation. We have recently watched a
precisely similar procedure in the instance of a carpenter-bee forming
a cell in a wooden post. (J. R.) The only difference was, that the bee
did not fly so far away with her fragments of wood as the wasp did; but
she varied the direction of her flight every time: and we could observe
that, after dropping, the chip of wood which she had carried off, she
did not return in a direct line to her nest, but made a circuit of some
extent before wheeling round to go back.
On observing the proceedings of this carpenter-bee next day, we found
her coming in with balls of pollen on her thighs; and on tracing her
from the nest into the adjacent garden, we saw her visiting every
flower which was likely to yield her a supply of pollen for her future
progeny. This was not all; we subsequently saw her taking the direction
of the clay quarry frequented by the mason-bees, as we have mentioned
in page 41, where we recognised her loading herself with a pellet of
clay, and carrying it into her cell in the wooden post. We observed
her alternating this labour for several days, at one time carrying
clay, and at another pollen; till at length she completed her task, and
closed the entrance with a barricade of clay, to prevent the intrusion
of any insectivorous depredator, who might make prey of her young; or
of some prying parasite, who might introduce its own eggs into the nest
she had taken so much trouble to construct.
Some days after it was finished, we cut into the post, and exposed this
nest to view. It consisted of six cells of a somewhat square shape, the
wood forming the lateral walls; and each was separated from the one
adjacent by a partition of clay, of the thickness of a playing card.
The wood was not lined with any extraneous substance, but was worked as
smooth as if it had been chiseled by a joiner. There were five cells,
arranged in a very singular manner--two being almost horizontal, two
perpendicular, and one oblique.
The depth to which the wood was excavated in this instance was
considerably less than what we have observed in other species which dig
perpendicular galleries several inches deep in posts and garden-seats;
and they are inferior in ingenuity to the carpentry of a bee described
by Réaumur (_Xylocopa violacea_), which has not been ascertained to be
a native of Britain, though a single indigenous species of the genus
has been doubtingly mentioned, and is figured by Kirby and Spence, in
their valuable 'Monographia.' If it ever be found here, its large size
and beautiful violet-coloured wings will render mistakes impossible.
[Illustration: Cells of Carpenter-Bees, excavated in an old post.
In fig. A the cells contain the young grubs; in fig. B the cells are
empty. Both figures are shown in section, and about half their natural
size.]
The violet carpenter-bee usually selects an upright piece of wood,
into which she bores obliquely for about an inch; and then, changing
the direction, works perpendicularly, and parallel to the sides of
the wood, from twelve or fifteen inches, and half an inch in breadth.
Sometimes the bee is contented with one or two of these excavations; at
other times, when the wood is adapted to it, she scoops out three or
four--a task which sometimes requires several weeks of incessant labour.
[Illustration: A represents a part of an espalier prop, tunnelled in
several places by the violet Carpenter-Bee: the stick is split, and
shows the nests and passages by which they are approached. B, a portion
of the prop, half the natural size. C, a piece of thin stick, pierced
by the Carpenter-Bee, and split, to show the nests. D, perspective view
of one of the partitions. E, Carpenter-Bee (_Xylocopa violacea_). F,
Teeth of the Carpenter-Bee, greatly magnified; _a_, the upper side;
_b_, the lower side.]
The tunnel in the wood, however, is only one part of the work; for
the little architect has afterwards to divide the whole into cells,
somewhat less than an inch in depth. It is necessary, for the proper
growth of her progeny, that each should be separated from the other,
and be provided with adequate food. She knows, most exactly, the
quantity of food which each grub will require during its growth; and
she therefore does not hesitate to cut it off from any additional
supply. In constructing her cells, she does not employ clay, like the
bee which we have mentioned above, but the sawdust, if we may call
it so, which she has collected in gnawing out the gallery. It would
not, therefore, have suited her design to scatter this about, as our
carpenter-bee did. The violet-bee, on the contrary, collects her
gnawings into a little store-heap for future use, at a short distance
from her nest. She proceeds thus:--At the bottom of her excavation she
deposits an egg, and over it fills a space nearly an inch high with
the pollen of flowers, made into a paste with honey. She then covers
this over with a ceiling composed of cemented sawdust, which also
serves for the floor of the next chamber above it. For this purpose she
cements round a wall a ring of wood-chips taken from her store-heap;
and within this ring forms another, gradually contracting the diameter
till she has constructed a circular plate, about the thickness of
a crown-piece, and of considerable hardness. This plate of course
exhibits concentric circles, somewhat similar to the annual circles
in the cross section of a tree. In the same manner she proceeds till
she has completed ten or twelve cells; and then she closes the main
entrance with a barrier of similar materials.
Let us compare the progress of this little joiner with a human
artisan--one who has been long practised in his trade, and has the most
perfect and complicated tools for his assistance. The bee has learnt
nothing by practice; she makes her nest but once in her life, but it is
then as complete and finished as if she had made a thousand. She has
no pattern before her--but the Architect of all things has impressed a
plan upon her mind, which she can realize without scale or compasses.
Her two sharp teeth are the only tools with which she is provided for
her laborious work; and yet she bores a tunnel, twelve times the length
of her own body, with greater ease than the workman who bores into the
earth for water, with his apparatus of augurs adapted to every soil.
Her tunnel is clean and regular; she leaves no chips at the bottom,
for she is provident of her materials. Further, she has an exquisite
piece of joinery to perform when her ruder labour is accomplished. The
patient bee works her rings from the circumference to the centre, and
she produces a shelf, united with such care with her natural glue, that
a number of fragments are as solid as one piece.
The violet carpenter-bee, as may be expected, occupies several weeks
in these complicated labours; and during that period she is gradually
depositing her eggs, each of which is successively to become a grub,
a pupa, and a perfect bee. It is obvious, therefore, as she does not
lay all her eggs in the same place--as each is separated from the
other by a laborious process--that the egg which is first laid will be
the earliest hatched; and that the first perfect insect, being older
than its fellows in the same tunnel, will strive to make its escape
sooner, and so on of the rest. The careful mother provides for this
contingency. She makes a lateral opening at the bottom of the cells;
for the teeth of the young bees would not be strong enough to pierce
the outer wood, though they can remove the cemented rings of sawdust in
the interior. Réaumur observed these holes, in several cases; and he
further noticed another external opening opposite to the middle cell,
which he supposed was formed, in the first instance, to shorten the
distance for the removal of the fragments of wood in the lower half of
the building.
* * * * *
That bees of similar habits, if not the same species as the violet-bee,
are indigenous to this country, is proved by Grew, who mentions, in his
'Rarities of Gresham College,' having found a series of such cells in
the middle of the pith of an elder branch, in which they were placed
lengthwise, one after another, with a thin boundary between each. As he
does not, however, tell us that he was acquainted with the insect which
constructed these, it might as probably be allied to the _Ceratina
albilabris_, of which Spinola has given so interesting an account in
the 'Annales du Muséum d'Histoire Naturelle' (x. 236). This noble and
learned naturalist tells us, that one evening he perceived a female
ceratina alight on the branch of a bramble, partly withered, and of
which the extremity had been broken; and, after resting a moment,
suddenly disappear. On detaching the branch, he found that it was
perforated, and that the insect was in the very act of excavating a
nidus for her eggs. He forthwith gathered a bundle of branches, both
of the bramble and the wild-rose, similarly perforated, and took them
home to examine them at leisure. Upon inspection, he found that the
nests were furnished like those of the same tribe, with balls of pollen
kneaded with honey, as a provision for the grubs.
The female ceratina selects a branch of the bramble or wild-rose which
has been accidentally broken, and digs into the pith only, leaving the
wood and bark untouched. Her mandibles, indeed, are not adapted for
gnawing wood; and, accordingly, he found instances in which she could
not finish her nest in branches of the wild-rose, where the pith was
not of sufficient diameter.
The insect usually makes her perforation a foot in depth, and divides
this into eight, nine, or even twelve cells, each about five lines
long, and separated by partitions formed by the gnawings of the pith,
cemented by honey, or some similar glutinous fluid, much in the same
manner with the _Xylocopa violacea_, which we have already described.
[This species is probably _Ceratina cærulea_, as the second species,
_C. albilabris_, seems to have little claim to be considered as a
British insect. It is plentiful in spots where it resides, but is very
local. It can best be found by collecting all the specimens of bramble
branches that have holes bored into the pith.
Mr. F. Smith says of this tiny bee, "Some years ago I observed a small
bee most industriously employed in excavating a dead bramble stick. My
attention was directed to the circumstance from observing some of the
fallen pieces of pith on the ground immediately beneath. Occasionally
fresh quantities of dust were pushed out. At length, the little
creature came out of the stick as if to rest, and after sunning itself
for a few minutes, it re-entered, and again commenced its labours.
Later in the day, after stopping up the entrance, I cut off the branch
and found in it a male and female ceratina."
The ceratina is only the sixth of an inch in length, and is deep
shining blue in colour.
There are many other species of British bees which frequent the stems
of bramble and other trees. One of them is known as _Prosopis signata_.
The cells made by the bees of this genus are lined with a membrane, and
are stocked with liquid honey. Some species will not take the trouble
of boring a tunnel for themselves, but will make use of hollow stones,
or similar localities, and place in them the silk-covered cocoons.
There are species of that versatile genus _Osmia_ (_O. leucomelana_),
in the habit of burrowing into dead bramble branches. The mother
insect bores a hole some six inches in length, throwing the pieces of
pith away, and then, depositing at the bottom an egg and a supply of
food, she forms a cell by fixing across the burrow a stopper made of
masticated leaves.
The stopper retains its place firmly, because the bee does not eat
away the whole of the pith, but alternately widens and contracts the
diameter of the burrow, each contracted portion being the termination
of a cell. The perfect insect appears in the early summer of the
following year.]
Carpenter-Wasps.
[Illustration: A, B, represent sections of old wooden posts, with
the cells of the Carpenter-Wasp. In fig. A the young grubs are shown
feeding on the insects placed there for their support by the parent
wasp. The cells in fig. B contain cocoons. C, Carpenter-Wasp, natural
size. D, cocoon of a Carpenter-Wasp, composed of sawdust and wings of
insects.]
As there are mason-wasps similar in economy to mason-bees, so are there
solitary carpenter-wasps which dig galleries in timber, and partition
them out into several cells by means of the gnawings of the wood which
they have detached. This sort of wasp is of the genus _Eumenes_. The
wood selected is generally such as is soft, or in a state of decay; and
the hole which is dug in it is much less neat and regular than that of
the carpenter-bees, while the division of the chambers is nothing more
than the rubbish produced during the excavation.
The provision which is made for the grub consists of flies or gnats
piled into the chamber, but without the nice order remarkable in
the spiral columns of green caterpillars provided by the mason-wasp
(_Odynerus murarius_). The most remarkable circumstance is, that in
some of the species, when the grub is about to go into the pupa state,
it spins a case (a cocoon), into which it interweaves the wings of the
flies whose bodies it has previously devoured. In other species, the
gnawings of the wood are employed in a similar manner.
[Some of the solitary wasps are also carpenters, and the genus _Crabro_
has several species which are classed under this head. There is, for
example, _Crabro clavipes_, a little black insect with red and black
abdomen, that burrows into dead bramble sticks, boring out the pith,
and forming a series of cells in the narrow tube thus made. Sometimes
this insect bores into decaying wood, but its general home is the
bramble-stick. The same habits are common to several other British
species of this genus, and the reader will find that old, decaying
willow trees are chiefly visited by these pretty little insects. Their
store of food, which they lay up for their young, mostly consists of
dipterous insects, and various species of gnats are used for this
purpose.
Another of the carpenter-wasps (_Pemphredon lugubris_) is really a
useful insect. It makes its burrows in posts, rails, and similar
localities, and provides its future young with a large stock of
aphides. It has been seen to settle on a rose-bush, scrape off the
branches a number of aphides, form them into a ball, and carry them off
between its head and front legs.
The colour of this insect is dull black, from which circumstance it
derives its name of _lugubris._ The head is large, and squared, and the
abdomen is attached to the thorax by a large footstalk. Its length is
about half an inch. It is a very common insect, and is believed to be
the only British representation of its genus.
Several species do not take the trouble to form a burrow for
themselves, but content themselves with building in holes ready made
for them. Straws are favourite resorts of such insects, and in thatched
buildings the straws of the roof are often filled with their cells.
One of these insects is a very little species, barely a quarter of an
inch in length. Its colour is black, with some silver white hair on
the face, and the legs are paler than the body. The abdomen has a long
footstalk. Its scientific name is _Psen pallipes_. Like the insect
which has just been described, it provisions its young with aphides.]
Upholsterer-Bees.
In another part of this volume we shall see how certain caterpillars
construct abodes for themselves, by cutting off portions of the
leaves or bark of plants, and uniting them by means of silk into a
uniform and compact texture; but this scarcely appears so wonderful
as the prospective labours of some species of bees for the lodgment
of their progeny. We allude to the solitary bees, known by the name
of the leaf-cutting bees, but which may be denominated more generally
_upholsterer-bees_, as there are some of them which use other materials
beside leaves.
One species of our little upholsterers has been called the poppy-bee
(_Osmia papaveris_, Latr.), from its selecting the scarlet petals of
the poppy as tapestry for its cells. Kirby and Spence express their
doubts whether it is indigenous to this country: we are almost certain
that we have seen the nests in Scotland. (J. R.) At Largs, in Ayrshire,
a beautiful sea-bathing village on the Firth of Clyde, in July, 1814,
we found in a footpath a great number of the cylindrical perforations
of the poppy-bee. [In his catalogue of British Hymenoptera, Mr. F.
Smith makes the following remarks with regard to this insect. "The
poppy-bee, _Anthocopa papaveris_, is closely allied to this genus
(_Osmia_), and may indeed be placed before it as a connecting link
with the _Osmia_. This interesting insect (_l'abeille Tapissiere_),
of Réaumur, has been supposed to inhabit this country, specimens
having been placed in the collection at the British Museum. But it was
with much regret that I discovered, when engaged upon the catalogue
of British bees for the Museum, and had occasion to examine each
individual specimen with care, that in the first place there was no
satisfactory evidence of the locality, and that in the next place, all
the males associated with the series were those of _Osmia adunca_, of
Panzear." For these reasons, this species has been excluded from the
list of British bees.] Réaumur remarked that the cells of this bee
which he found at Bercy, were situated in a northern exposure, contrary
to what he had remarked in the mason-bee, which prefers the south. The
cells at Largs, however, were on an elevated bank, facing the south,
near Sir Thomas Brisbane's observatory. With respect to exposure,
indeed, no certain rule seems applicable; for the nests of mason-bees
which we found on the wall of Greenwich Park faced the north-east, and
we have often found carpenter-bees make choice of a similar situation.
In one instance, we found carpenter-bees working indifferently on the
north-east and south-west side of the same post.
As we did not perceive any heaps of earth near the holes at Largs,
we concluded that it must either have been carried off piecemeal
when they were dug, or that they were old holes re-occupied (a
circumstance common with bees), and that the rubbish had been trodden
down by passengers. Réaumur, who so minutely describes the subsequent
operations of the bee, says nothing respecting its excavations. One
of these holes is about three inches deep, gradually widening as it
descends, till it assumes the form of a small Florence flask. The
interior of this is rendered smooth, uniform, and polished, in order
to adapt it to the tapestry with which it is intended to be hung, and
which is the next step in the process.
The material used for tapestry by the insect upholsterer is supplied
by the flower-leaves of the scarlet field-poppy, from which she
successively cuts off small pieces of an oval shape, seizes them
between her legs, and conveys them to the nest. She begins her work at
the bottom, which she overlays with three or four leaves in thickness,
and the sides have never less than two. When she finds that the piece
she has brought is too large to fit the place intended, she cuts off
what is superfluous, and carries away the shreds. By cutting the
fresh petal of a poppy with a pair of scissors, we may perceive the
difficulty of keeping the piece free from wrinkles and shrivelling;
but the bee knows how to spread the pieces which she uses as smooth as
glass.
When she has in this manner hung the little chamber all around with
this splendid scarlet tapestry, of which she is not sparing, but
extends it even beyond the entrance, she then fills it with the pollen
of flowers mixed with honey, to the height of about half an inch. In
this magazine of provisions for her future progeny she lays an egg, and
over it folds down the tapestry of poppy-petals from above. The upper
part is then filled in with earth; but Latreille says he has observed
more than one cell constructed in a single excavation. This may account
for Réaumur's describing them as sometimes seven inches deep; a
circumstance which Latreille, however, thinks very surprising.
It will, perhaps, be impossible ever to ascertain, beyond a doubt,
whether the tapestry-bee is led to select the brilliant petals of the
poppy from their colour, or from any other quality they may possess, of
softness or of warmth, for instance. Réaumur thinks that the largeness,
united with the flexibility of the poppy-leaves, determines her
choice. Yet it is not improbable that her eye may be gratified by the
appearance of her nest; that she may possess a feeling of the beautiful
in colour, and may look with complacency upon the delicate hangings
of the apartment which she destines for her offspring. Why should not
an insect be supposed to have a glimmering of the value of ornament?
How can we pronounce, from our limited notion of the mode in which the
inferior animals think and act, that their gratifications are wholly
bounded by the positive utility of the objects which surround them? Why
does a dog howl at the sound of a bugle, but because it offends his
organ of hearing?--and why, therefore, may not a bee feel gladness in
the brilliant hues of her scarlet drapery, because they are grateful to
her organs of sight? All these little creatures work, probably, with
more neatness and finish than is absolutely essential for comfort; and
this circumstance alone would imply that they have something of taste
to exhibit, which produces to them a pleasurable emotion.
The tapestry-bee is, however, content with ornamenting the interior
only of the nest which she forms for her progeny. She does not
misplace her embellishments with the error of some human artists. She
desires security as well as elegance; and, therefore, she leaves no
external traces of her operations. Hers is not a mansion rich with
columns and friezes without, but cold and unfurnished within, like the
desolate palaces of Venice. She covers her tapestry quite round with
the common earth; and leaves her eggs enclosed in their poppy-case
with a certainty that the outward show of her labours will attract no
plunderer.
The poppy-bee may be known by its being rather more than a third of
an inch long, of a black colour, studded on the head and back with
reddish-grey hairs; the belly being grey and silky, and the rings
margined with grey above, the second and third having an impressed
transversal line.
* * * * *
A species of solitary bee (_Anthidium manicatum_, Fabricius), by no
means uncommon with us, forms a nest of a peculiarly interesting
structure. Kirby and Spence say, that it does not excavate holes, but
makes choice of the cavities of old trees, key-holes, and similar
localities; yet it is highly probable, we think, that it may sometimes
scoop out a suitable cavity when it cannot find one; for its mandibles
seem equally capable of this, with those of any of the carpenter or
mason-bees.
Be this as it may, the bee in question having selected a place suitably
sheltered from the weather, and from the intrusion of depredators,
proceeds to form her nest, the exterior walls of which she forms of the
wool of pubescent plants, such as rose-campion (_Lychnis coronaria_),
the quince (_Pyrus cydonia_), cats-ears (_Stachys lunata_), &c. "It
is very pleasant," says Mr. White, of Selborne, "to see with what
address this insect strips off the down, running from the top to the
bottom of the branch, and shaving it bare with all the dexterity of
a hoop-shaver. When it has got a vast bundle, almost as large as
itself, it flies away, holding it secure between its chin and its
fore-legs."[Q] The material is rolled up like a ribbon; and we possess
a specimen in which one of these rolls still adheres to a rose-campion
stem, the bee having been scared away before obtaining her load.
The manner in which the cells of the nest are made seems not to be
very clearly understood. M. Latreille says, that, after constructing
her nest of the down of quince-leaves, she deposits her eggs, together
with a store of paste, formed of the pollen of flowers, for nourishing
the grubs. Kirby and Spence, on the other hand, tell us, that "the
parent bee, _after_ having constructed her cells, laid an egg in each,
and filled them with a store of suitable food, plasters them with a
covering of vermiform masses, apparently composed of honey and pollen;
and having done this, aware, long before Count Rumford's experiments,
what materials conduct heat most slowly," she collects the down from
woolly plants, and "sticks it upon the plaster that covers her cells,
and thus closely envelops them with a warm coating of down, impervious
to every change of temperature." "From later observations," however,
they are "inclined to think that these cells may possibly, as in the
case of the humble-bee, be in fact formed by the larva previously to
becoming a pupa, after having eaten the provision of pollen and honey
with which the parent bee had surrounded it. The vermicular shape,
however, of the masses with which the cases are surrounded, does not
seem easily reconcilable with this supposition, unless they are
considered as the excrement of the larva."[R]
Whether or not this second explanation is the true one, we have not
the means of ascertaining; but we are almost certain the first is
incorrect, as it is contrary to the regular procedure of insects to
begin with the interior part of any structure, and work outwards. We
should imagine, then, that the down is first spread out into the form
required, and afterwards plastered on the inside to keep it in form,
when probably the grub spins the vermicular cells previous to its
metamorphosis.
It might prove interesting to investigate this more minutely; and as
the bee is by no means scarce in the neighbourhood of London, it might
not be difficult for a careful observer to witness all the details
of this singular architecture. Yet we have repeatedly endeavoured,
but without success, to watch the bees, when loaded with down, to
their nests. The bee may be readily known from its congeners, by its
being about the size of the hive-bee, but more broad and flattened,
blackish-brown above, with a row of six yellow or white spots along
each side of the rings, very like the rose-leaf cutter, and having the
belly covered with yellowish-brown hair, and the legs fringed with long
hairs of a rather lighter colour.
* * * * *
[This bee does not bore a tunnel for herself, but occupies that of some
other insect. The nests of this insect are generally to be obtained
from old willows, because these trees are so largely bored by the
goat-moth caterpillar, and afford ample space for the larva. The woolly
substance obtained from the plant is pressed against the sides of the
burrow, so as to form a lining. She then makes a series of cells of a
similar material, and the young larva, when it is about to change into
the pupa state, envelops itself in a silken covering of a brown colour.
It is a curious fact, that the male of this insect is considerably
larger than the female, thus reversing the usual order of things among
insects. Only one species of this bee is known in England.]
A common bee belonging to the family of upholsterers is called the
rose-leaf cutter (_Megachile centuncularis_, Latr.). The singularly
ingenious habits of this bee have long attracted the attention of
naturalists; but the most interesting description is given by Réaumur.
So extraordinary does the construction of their nests appear, that a
French gardener having dug up some, and believing them to be the work
of a magician, who had placed them in his garden with evil intent,
sent them to Paris to his master, for advice as to what should be done
by way of exorcism. On applying to the Abbé Nollet, the owner of the
garden was soon persuaded that the nests in question were the work of
insects; and M. Réaumur, to whom they were subsequently sent, found
them to be the nests of one of the upholsterer-bees, and probably of
the rose-leaf cutter, though the nests in question were made of the
leaves of the mountain ash (_Pyrus aucuparia_).
The rose-leaf cutter makes a cylindrical hole in a beaten pathway,
for the sake of more consolidated earth (or in the cavities of walls
or decayed wood), from six to ten inches deep, and does not throw
the earth dug out from it into a heap, like the Andrenæ.[S] In this
she constructs several cells about an inch in length, shaped like a
thimble, and made of cuttings of leaves (not petals), neatly folded
together, the bottom of one thimble-shaped cell being inserted into the
mouth of the one below it, and so on in succession.
[Illustration: Rose-leaf cutter Bees, and Nest lined with rose-leaves.]
It is interesting to observe the manner in which this bee procures
the materials for forming the tapestry of her cells. The leaf of the
rose-tree seems to be that which she prefers, though she sometimes
takes other sorts of leaves, particularly those with serrated margins,
such as the birch, the perennial mercury (_Mercurialis perennis_),
mountain-ash, &c. She places herself upon the outer edge of the
leaf which she has selected, so that its margin may pass between her
legs. Turning her head towards the point, she commences near the
footstalk, and with her mandibles cuts out a circular piece with as
much expedition as we could do with a pair of scissors, and with more
accuracy and neatness than could easily be done by us. As she proceeds,
she keeps the cut portion between her legs, so as not to impede her
progress; and using her body for a _trammel_, as a carpenter would
say, she cuts in a regular curved line. As she supports herself during
the operation upon the portion of the leaf which she is detaching,
it must be obvious, when it is nearly cut off, that the weight of
her body might tear it away, so as to injure the accuracy of its
curvilineal shape. To prevent any accident of this kind, as soon as
she suspects that her weight might tear it, she poises herself on
her wings, till she has completed the incision. It has been said, by
naturalists, that this manoeuvre of poising herself on the wing, is to
prevent her falling to the ground, when the piece gives way; but as no
winged insect requires to take any such precaution, our explanation is
probably the true one.
With the piece which she has thus cut out, held in a bent position
perpendicularly to her body, she flies off to her nest, and fits it
into the interior with the utmost neatness and ingenuity; and, without
employing any paste or glue, she trusts, as Réaumur ascertained, to
the spring the leaf takes in drying, to retain it in its position. It
requires from nine to ten pieces of leaf to form one cell, as they
are not always of precisely the same thickness. The interior surface
of each cell consists of three pieces of leaf, of equal size, narrow
at one end, but gradually widening at the other, where the width
equals half the length. One side of each of the pieces is the serrated
margin of the leaf from which it was cut, and this margin is always
placed outermost, and the cut margin innermost. Like most insects, she
begins with the exterior, commencing with a layer of tapestry, which
is composed of three or four oval pieces, larger in dimensions than
the rest, adding a second and a third layer proportionately smaller.
In forming these, she is careful not to place a joining opposite to a
joining, but with all the skill of a consummate artificer, lays the
middle of each piece of leaf over the margins of the others, so as by
this means both to cover and strengthen the junctions. By repeating
this process, she sometimes forms a fourth or a fifth layer of leaves,
taking care to bend the leaves at the narrow extremity or closed end of
the cell, so as to bring them into a convex shape.
When she has in this manner completed a cell, her next business is to
replenish it with a store of honey and pollen, which, being chiefly
collected from thistles, forms a beautiful rose-coloured conserve. In
this she deposits a single egg, and then covers in the opening with
three pieces of leaf, so exactly circular, that a pair of compasses
could not define their margin with more accuracy. In this manner the
industrious and ingenious upholsterer proceeds till the whole gallery
is filled, the convex extremity of the one fitting into the open end of
the next, and serving both as a basis and as the means of strengthening
it. If, by any accident, the labour of these insects is interrupted or
the edifice deranged, they exhibit astonishing perseverance in setting
it again to rights. Insects, indeed, are not easily forced to abandon
any work which they may have begun.
The monkish legends tell us that St. Francis Xavier, walking one day
in a garden, and seeing an insect, of the _Mantis_ genus, moving along
in its solemn way, holding up its two fore legs, as in the act of
devotion, desired it to sing the praises of God. The legend adds that
the saint immediately heard the insect carol a fine canticle with a
loud emphasis. We want no miraculous voice to record the wonders of the
Almighty hand, when we regard the insect world. The little rose-leaf
cutter, pursuing her work with the nicest mathematical art--using no
artificial instruments to form her ovals and her circles--knowing
that the elastic property of the leaves will retain them in their
position--making her nest of equal strength throughout, by the most
rational adjustment of each distinct part--demands from us something
more than mere wonder; for such an exercise of instinctive ingenuity
at once directs our admiration to the great Contriver, who has so
admirably proportioned her knowledge to her necessities.
_CHAPTER IV._
CARDER-BEES; HUMBLE-BEES; SOCIAL-WASPS.
The bees and wasps, whose ingenious architecture we have already
examined, are solitary in their labours. Those we are about to describe
live in society. The perfection of the social state among this class of
insects is certainly that of the hive-bees. They are the inhabitants of
a large city, where the arts are carried to a higher excellence than
in small districts enjoying little communication of intelligence. But
the bees of the villages, if we may follow up the parallel, are not
without their interest. Such are those which are called carder-bees and
humble-bees.
Carder-Bees.
The nests of the bees which Réaumur denominates carders (_Bombus
muscorum_, Latr.) are by no means uncommon, and are well worth the
study of the naturalist. During the hay harvest, they are frequently
met with by mowers in the open fields and meadows; but they may
sometimes be discovered in hedge-banks, the borders of copses, or among
moss-grown stones. The description of the mode of building adopted
by this bee has been copied by most of our writers on insects from
Réaumur; though he is not a little severe on those who write without
having ever had a single nest in their possession. We have been able to
avoid such a reproach; for we have now before us a very complete nest
of carder-bees, which differs from those described by Réaumur, in being
made not of moss, but withered grass. With this exception, we find that
his account agrees accurately with our own observations. (J. R.)
[Illustration: Fig. A represents two Carder-Bees heckling moss for
their Nests; B, exterior view of the Nest of the Carder-Bee.]
The carder-bees select for their nest a shallow excavation about
half a foot in diameter; but when they cannot find one to suit their
purpose, they undertake the Herculean task of digging one themselves.
They cover this hollow with a dome of moss--sometimes, as we have
ascertained, of withered grass. They make use, indeed, of whatever
materials may be within their reach; for they do not attempt to bring
anything from a distance, not even when they are deprived of the
greater portion by an experimental naturalist. Their only method of
transporting materials to the building is by pushing them along the
ground--the bee, for that purpose, working backwards, with its head
turned from the nest. If there is only one bee engaged in this labour,
as usually happens in the early spring, when a nest is founded by a
solitary female who has outlived the winter, she transports her little
bundles of moss or grass by successive backward pushes, till she gets
them home.
In the latter part of the season, when the hive is populous and can
afford more hands, there is an ingenious division of this labour. A
file of bees, to the number sometimes of half a dozen, is established,
from the nest to the moss or grass which they intend to use, the heads
of all the file of bees being turned from the nest and towards the
material. The last bee of the file lays hold of some of the moss with
her mandibles, disentangles it from the rest, and having _carded_ it
with her fore legs into a sort of felt or small bundle, she pushes it
under her body to the next bee, who passes it in the same manner to the
next, and so on till it is brought to the border of the nest,--in the
same way as we sometimes see sugar-loaves conveyed from a cart to a
warehouse, by a file of porters throwing them from one to another.
The elevation of the dome, which is all built from the interior, is
from four to six inches above the level of the field. Beside the moss
or grass, they frequently employ coarse wax to form the ceiling of the
vault, for the purpose of keeping out rain, and preventing high winds
from destroying it. Before this finishing is given to the nest, we have
remarked, that on a fine sunshiny day the upper portion of the dome was
opened to the extent of more than an inch, in order, we suppose, to
forward the hatching of the eggs in the interior; but on the approach
of night this was carefully covered in again. It was remarkable that
the opening which we have just mentioned was never used by the bees for
either their entrance or their exit from the nest, though they were all
at work there, and, of course, would have found it the readiest and
easiest passage; but they invariably made their exit and their entrance
through the covert-way or gallery which opens at the bottom of the
nest, and, in some nests, is about a foot long and half an inch wide.
This is, no doubt, intended for concealment from field-mice, polecats,
wasps, and other depredators.
On removing a portion of the dome and bringing the interior of the
structure into view, we find little of the architectural regularity
so conspicuous in the combs of a common bee-hive: instead of this
symmetry, there are only a few egg-shaped, dark-coloured cells, placed
somewhat irregularly, but approaching more to the horizontal than to
the vertical position, and connected together with small amorphous[T]
columns of brown wax. Sometimes there are two or three of these oval
cells placed one above another, without anything to unite them.
These cells are not, however, the workmanship of the old bees, but of
their young grubs, who spin them when they are about to change into
nymphs. But, from these cases, when they are spun, the enclosed insects
have no means of escaping, and they depend for their liberation on the
old bees gnawing off the covering, as is done also by ants in the same
circumstances. The instinct with which they know the precise time when
it is proper to do this is truly wonderful. It is no less so, that
these cocoons are by no means useless when thus untenanted, for they
subsequently serve for honey-pots, and are indeed the only store-cells
in the nest. For this purpose the edge of the cell is repaired and
strengthened with a ring of wax.
[Illustration: Breeding-Cells.]
The true breeding-cells are contained in several amorphous masses of
brown-coloured wax, varying in dimensions, but of a somewhat flat and
globular shape. On opening any of these, a number of eggs or grubs are
found, on whose account the mother bee has collected the masses of
wax, which also contain a supply of pollen moistened with honey, for
their subsistence.
The number of eggs or grubs found in one spheroid of wax varies from
three to thirty, and the bees in a whole nest seldom exceed sixty.
There are three sizes of bees, of which the females are the largest;
but neither these nor the males are, as in the case of the hive-bee,
exempt from labour, the females, indeed, always found the nests, since
they alone survive the winter, all the rest perishing with cold. In
each nest, also, are several females, that live in harmony together.
[Illustration: Interior views of Carder-Bee's Nest.]
The carder-bees may be easily distinguished from their congeners (of
the same genus), by being not unlike the colour of the withered moss
with which they build their nests, having the fore part of their
back a dull orange, and hinder part ringed with different shades of
greyish yellow. They are not so large as the common humble-bee (_Bombus
terrestris_, Latr.), but rather shorter and thicker in the body than
the common hive-bee (_Apis mellifica_).
Lapidary-Bees.
A bee still more common, perhaps, than the carder is the orange-tailed
bee, or lapidary (_Bombus lapidaria_), readily known by its general
black colour and reddish orange tail. It builds its nest sometimes
in stony ground, but prefers a heap of stones such as are gathered
off grass fields or are piled up near quarries. Unlike the carder,
the lapidary carries to its nest bits of moss, which are very neatly
arranged into a regular oval. These insects associate in their labours;
and they make honey with great industry. The individuals of a nest
are more numerous than the carders, and likewise more pertinaciously
vindictive. About two years ago we discovered a nest of these bees at
Compton-Bassett, in Wiltshire, in the centre of a heap of limestone
rubbish; but owing to the brisk defensive warfare of their legionaries,
we could not obtain a view of the interior. It was not even safe to
approach within many yards of the place; and we do not exaggerate when
we say that several of them pursued us most pertinaciously about a
quarter of a mile. (J. R.)
Humble-Bees.
The common humble-bee (_Bombus terrestris_) is precisely similar in
its economy to the two preceding species, with this difference, that
it forms its nest underground like the common wasp, in an excavated
chamber, to which a winding passage leads, of from one to two feet, and
of a diameter sufficient to allow of two bees passing. The cells have
no covering beside the vault of the excavation and patches of coarse
wax similar to that of the carder-bee.
[The accompanying illustration represents a group of cells made by this
species. As may be seen by reference to the engraving, they are not
placed with any regularity, but seem to be tossed about at random.
[Illustration]
Some of the cells contain larvæ, in others, those closely sealed, lie
the pupæ in different stages of development, and some of the cells
are filled with a very fragrant and sweet honey, which, however, is
injurious to many persons, giving them severe and persistent headaches,
even though taken in small quantities.]
Social-Wasps.
The nest of the common wasp (_Vespa vulgaris_) attracts more or less
the attention of everybody; but its interior architecture is not so
well known as it deserves to be, for its singular ingenuity, in which
it rivals even that of the hive-bee (_Apis mellifica_). In their
general economy the social or republican wasps closely resemble the
humble-bee (_Bombus_), every colony being founded by a single female
who has survived the winter, to the rigours of which all her summer
associates of males and working wasps uniformly fall victims. Nay, out
of three hundred females which may be found in one vespiary, or wasp's
nest, towards the close of autumn, scarcely ten or a dozen survive till
the ensuing spring, at which season they awake from their hibernal
lethargy, and begin with ardour the labours of colonization.
It may be interesting to follow one of these mother wasps through her
several operations, in which she merits more the praise of industry
than the queen of a bee-hive, who does nothing, and never moves without
a numerous train of obedient retainers, always ready to execute her
commands and to do her homage. The mother wasp, on the contrary, is
at first alone, and is obliged to perform every species of drudgery
herself.
Her first care, after being roused to activity by the returning warmth
of the season, is to discover a place suitable for her intended colony;
and, accordingly, in the spring, wasps may be seen prying into every
hole of a hedge-bank, particularly where field-mice have burrowed.
Some authors report that she is partial to the forsaken galleries of
the mole; but this does not accord with our observations, as we have
never met with a single vespiary in any situation likely to have been
frequented by moles. But though we cannot assert the fact, we think it
highly probable that the deserted nest of the field-mouse, which is
not uncommon in hedge-banks, may be sometimes appropriated by a mother
wasp as an excavation convenient for her purpose. Yet, if she does make
choice of the burrow of a field-mouse, it requires to be afterwards
considerably enlarged in the interior chamber, and the entrance gallery
very much narrowed.
The desire of the wasp to save herself the labour of excavation, by
forming her nest where other animals have burrowed, is not without
a parallel in the actions of quadrupeds, and even of birds. In the
splendid continuation of Wilson's American Ornithology, by Charles L.
Bonaparte (whose scientific pursuits have thrown around that name
a beneficent lustre, pleasingly contrasted with his uncle's glory),
there is an interesting example of this instinctive adoption of the
labours of others. "In the trans-Mississippian territories of the
United States, the burrowing-owl resides exclusively in the villages
of the marmot, or prairie-dog, whose excavations are so commodious as
to render it unnecessary that the owl should dig for himself, as he is
said to do where no burrowing animals exist.[U] The villages of the
prairie-dog are very numerous and variable in their extent,--sometimes
covering only a few acres, and at others spreading over the surface of
the country for miles together. They are composed of slightly-elevated
mounds, having the form of a truncated cone, about two feet in width
at the base, and seldom rising as high as eighteen inches from the
surface of the soil. The entrance is placed either at the top or on
the side, and the whole mound is beaten down externally, especially
at the summit, resembling a much-used footpath. From the entrance,
the passage into the mound descends vertically for one or two feet,
and is thence continued obliquely downwards until it terminates in an
apartment, within which the industrious prairie-dog constructs, on the
approach of cold weather, a comfortable cell for his winter's sleep.
The cell, which is composed of fine dry grass, is globular in form,
with an opening at top, capable of admitting the finger; and the whole
is so firmly compacted, that it might without injury be rolled over the
floor."[V]
In case of need the wasp is abundantly furnished by nature with
instruments for excavating a burrow out of the solid ground, as she no
doubt most commonly does--digging the earth with her strong mandibles,
and carrying it off or pushing it out as she proceeds. The entrance
gallery is about an inch or less in diameter, and usually runs in a
winding or zig-zag direction, from one to two feet in depth. In the
chamber to which this gallery leads, and which, when completed, is from
one to two feet in diameter, the mother wasp lays the foundations of
her city, beginning with the walls.
The building materials employed by wasps were long a matter of
conjecture to scientific inquirers; for the bluish-grey papery
substance of the whole structure has no resemblance to any sort of wax
employed by bees for a similar purpose. Now that the discovery has
been made, we can with difficulty bring ourselves to believe that a
naturalist so acute and indefatigable as M. Réaumur, should have, for
twenty years, as he tells us, endeavoured, without success, to find
out the secret. At length, however, his perseverance was rewarded. He
remarked a female wasp alight on the sash of his window, and begin to
gnaw the wood with her mandibles; and it struck him at once that she
was procuring materials for building. He saw her detach from the wood a
bundle of fibres about a tenth of an inch in length, and finer than a
hair; and as she did not swallow these, but gathered them into a mass
with her feet, he could not doubt that his first idea was correct. In
a short time she shifted to another part of the window-frame, carrying
with her the fibres she had collected, and to which she continued to
add, when he caught her, in order to examine the nature of her bundle;
and he found that it was not yet moistened nor rolled into a ball, as
is always done before employing it in building. In every other respect
it had precisely the same colour and fibrous texture as the walls of a
vespiary. It struck him as remarkable that it bore no resemblance to
wood gnawed by other insects, such as the goat-moth caterpillar, which
is granular like sawdust. This would not have suited the design of the
wasp, who was well aware that fibres of some length form a stronger
texture. He even discovered, that before detaching the fibres, she
bruised them (_les charpissoit_) into a sort of lint (_charpie_) with
her mandibles. All this the careful naturalist imitated by bruising
and paring the same wood of the window-sash with his penknife, till
he succeeded in making a little bundle of fibres scarcely to be
distinguished from that collected by the wasp.
We have ourselves frequently seen wasps employed in procuring their
materials in this manner, and have always observed that they shift
from one part to another more than once in preparing a single load--a
circumstance which we ascribe entirely to the restless temper peculiar
to the whole order of hymenopterous insects. Réaumur found that
the wood which they preferred was such as had been long exposed to
the weather, and is old and dry. White of Selborne, and Kirby and
Spence, on the contrary, maintain that wasps obtain their paper from
sound timber, hornets only from that which is decayed.[W] Our own
observations, however, confirm the statement of Réaumur with respect
to wasps, as, in every instance which has fallen under our notice, the
wood selected was very much weathered; and in one case, an old oak post
in a garden at Lee, in Kent, half destroyed by dry-rot, was seemingly
the resort of all the wasps in the vicinity. In another case, the deal
bond in a brick wall, which had been built thirty years, is at this
moment (June, 1829) literally striped with the gnawings of wasps, which
we have watched at the work for hours together. (J. R.)
[Different species of wasps use different materials for their nest.
_Vespa vulgaris_ always uses decayed wood, while _V. germanica_ and
other species use sound wood. Owing to the colour, the distinction
between the nests of these insects is evident at a glance.
The bundles of ligneous fibres thus detached are moistened before being
used, with a glutinous liquid, which causes them to adhere together,
and are then kneaded into a sort of paste, or _papier maché_.
The method employed by the wasp in making its nest has been so
admirably described by Mr. S. Stone, that we cannot do better than copy
his description, which appeared in "Beeton's Annual" of 1865.
"Having found a place suitable--the deserted burrows of the field-mice
being perhaps more generally selected than any other by the underground
species, the chamber formed by that animal for its nest being exactly
the kind of place required by the insect--it proceeds to attach its web
to the centre of the roof of the chamber. This consists, in the first
instance, of a pedicle, or footstalk, about half an inch in length,
at the extremity of which a single cell is formed, which is presently
surrounded by others.
"Simultaneously with the formation of these cells, an umbrella-shaped
covering is prepared above them. More cells are added, an egg being
deposited in each of them as soon as formed, while constant additions
are made to the covering until it has assumed a globular form, with
only an aperture sufficiently large for the insect to pass in and out.
Before the completion of the first covering, a second, just large
enough to enclose it, is begun, and while this is in progress a third
is commenced, and then a fourth, and so on. When young wasps have
been produced in sufficient numbers to carry on the work without the
assistance of the parent, an event which usually takes place in about
six weeks from the commencement of the nest, she does not again leave
home, but occupies herself solely in the task of depositing eggs as
fast as cells can be formed by the workers for their reception.
"There are two methods by which the nests are enlarged by the workers
after the queen has given up the task of building; some species
choosing one, some adopting the other. One consists in forming a series
of regular sheets or layers, which are made to overlap each other like
the slates or tiles on the roof of a building, in the same way as is
pursued by the queen of every species so long as she continues to be
the architect. When a few of these sheets have been completed, that
is, when they have been made to assume a spherical form, with only a
small aperture for ingress and egress, each internal sheet is cut away,
nearly but not quite, as fast as additional ones are formed externally,
the shell or covering therefore slightly increasing in thickness as
the nest increases in size. Thus architects among the human race are
careful to proportion the thickness, and consequently the strength of
the walls to the magnitude of the building designed to be erected.
"The other method consists in forming hollow pieces, or raising, as it
were, blisters all over the plain surface which the queen has left;
and upon these other blisters, and so on continually; cutting away,
as in the former case, the under skin on the formation of the outer
one. The latter method is adopted by the workers of _V. crabro_, _V.
vulgaris_, and _V. germanica_; the former by _V. Norvegica_, _V.
sylvestris_, _V. rufa_, and probably by _V. arborea_. Cutting away the
inner portions of the coverings is a necessary process in order to make
room for the increased size of the comb or combs. The material cut away
is not thrown by as useless, but is worked up afresh; indeed this is
effected in, and by, the very act of removing it; it is then either
used in enlarging the combs or it is brought out and employed in making
additions to the outside.
"As the nest increases in size, it is obvious that the cavity in which
it is placed must be proportionably enlarged; accordingly, each wasp,
as it emerges from the aperture, may be observed to bring out with
it a small lump of earth which it has scraped from the walls of the
chamber, care being taken to keep a clear space of about a quarter of
an inch between the covering of the nest, and the walls of the chamber.
About the same space also occurs between the combs, which are placed
horizontally, with the mouth of the cells downwards; supporting columns
or pillars being constructed at regular intervals so as to keep them at
a proper distance apart, thus allowing the insects room to pass between
them for the purpose of feeding the grubs. Supporting columns or
pillars are also placed between the roof of the chamber and the crown
of the nest, connecting the one with the other; and these supports are
constantly strengthened as the increasing weight of the nest renders
such a precaution necessary.
"The material of which the wasps' nests are composed is a sort of
paper manufactured chiefly from wood by the insects themselves; one
species using sound wood for the purpose, another that which has become
decayed. This they scrape by means of their jaws from posts, rails,
gates, hurdles, &c., in which act it becomes mixed with some peculiar
fluid with which they are provided; it then possesses nearly the same
properties as the pulp from which paper is made, but is of firmer
consistence. This is gathered in a small lump under the chest, to which
it adheres, and in that way is carried to the nest.
"The operators having, after the exhibition of a considerable amount of
fickleness in the choice, fixed upon a suitable place for commencing,
or recommencing operations--for these remarks have reference to a nest
already somewhat advanced in the building--place themselves along the
edge of a yet unfinished piece, then walking slowly backward, spread
the material as they go, along this edge, where it forms a thick
streak; they then go forward to the point at which they began to spread
the composition, again marching slowly backward, press this streak
between their jaws, which acts as a pair of pincers, thus thinning it
out throughout its whole length. They then go forward a second time,
pressing it still thinner, and then a third, and so on, until they
have rendered it sufficiently thin. Before this is accomplished, the
operators have generally to go five or six times over their work. They
do not return to the same spot with their next burden, but seek a fresh
one, and thus allow the work they recently executed to become dry and
firm, previous to making further additions to it. Possibly the material
first 'used up' was from wood of a dark colour; the next may be from
light-coloured wood, and the next from that of an intermediate colour;
and this it is which gives so much beauty to the coverings of the nests
of these insects.
"_Vespa crabro_ and _V. vulgaris_ are the only species which use
decayed wood or touchwood in the fabrication of their nests; the other
species employ sound wood, varied occasionally by sound vegetable fibre
obtained from plants of different kinds.
"From the upper combs in a nest, workers are produced; from the lower
ones, queens or females; and from the intermediate ones, males. Workers
become developed early in the season, males not till an advanced
period; and young females or queens not until towards the close of the
season.
"The nests of _V. crabro_, _V. vulgaris_, and _V. germanica_, when
of full size, measure not unfrequently twelve inches in diameter,
the communities working on, in a favourable season, until the month
of November; while the labours of the other species close, and the
communities break up towards the end of August; their nests scarcely
attaining to half the size of those above mentioned."
The accompanying illustration exhibits the nest of the common wasp in
an early stage. The first cover has been completed, and a second is in
course of progress. We have now before us a beautiful series of wasps'
nests, in their various stages, prepared by Mr. Stone, in order to show
the progressive enlargement of the edifice.
[Illustration: Nest of Wasp in an early stage.]
First, there is the single cell attached to a small part that had
penetrated the roof of the burrow. Next comes a more advanced stage, in
which three cells are made, and the roof is just begun, being not quite
half an inch in diameter. Then come five cells, and a tolerably large
roof; and then twelve cells, with a complete roof.
The next stage is that which is represented in the illustration, where
the group of cells is seen suspended from its slender footstalk, and
a second covering is in progress. By degrees the nest enlarges until
the second layer or tier of cells is begun, while the first tier is
occupied in the centre by the pupæ, sheltered by their little silk
doors, and on the circumference by the larvæ, whose cells are still
open in order to allow themselves to be fed by the nurse-wasps.
[Illustration: Section of the same Nest, showing the first tier of
Cells.]
In these nests, the difference between the homes of _Vespa vulgaris_
and those of _V. germanica_ is very strongly marked, the former being
yellowish brown, and the latter grey. One nest of _V. germanica_, is
remarkable for being thickly studded with the long, white eggs of some
insect, probably a parasite, which has gained admittance to the burrow,
in spite of the care of its guardians. It may be here mentioned, that
_V. germanica_ is by far the most common species of wasp in England.
The illustration at p. 90 represents a completed nest of _V.
germanica_. The rough, thick covering is seen outside, and within
are the tiers of cells, each layer being supported by pillars from
the layer immediately above. These pillars are always formed at the
angle where these cells touch each other, so as to obtain as strong a
foundation as possible. Only a very small space is left between the
combs, just enough room, in fact, for the nurse-wasps to pass as they
feed the young. The reader will remember that the young wasps all hang
with their heads downwards, being held in their places by a sort of
clasper at the end of the tail.]
When the foundress-wasp has completed a certain number of cells, and
deposited eggs in them, she soon intermits her building operations,
in order to procure food for the young grubs, which now require all
her care. In a few weeks these become perfect wasps, and lend their
assistance in the extension of the edifice; enlarging the original
coping of the foundress by side walls, and forming another platform of
cells, suspended to the first by columns, as that had been suspended to
the ceiling.
[Illustration: Section of the Social-Wasp's Nest.
_a a_, the external wall; _b_, _c c_, five small terraces of cells for
the neuter wasps, _d d_, _e e_, three rows of larger cells for the
males and females.]
In this manner several platforms of combs are constructed, the outer
walls being extended at the same time; and, by the end of the summer,
there is generally from twelve to fifteen platforms of cells. Each
contains about 1060 cells--forty-nine being contained in an inch and a
half square, and, of course, making the enormous number of about 16,000
cells in one colony. Réaumur, upon these data, calculates that one
vespiary may produce every year more than 30,000 wasps, reckoning only
10,000 cells, and each serving successively for the cradle of three
generations. But, although the whole structure is built at the expense
of so much labour and ingenuity, it has scarcely been finished before
the winter sets in, when it becomes nearly useless, and serves only for
the abode of a few benumbed females, who abandon it on the approach of
spring, and never return; for wasps do not, like mason-bees, ever make
use of the same nest for more than one season.
[Illustration: A, represents one of the rods from which the terraces
are suspended. B, a portion of the external crust.]
Both Réaumur and the younger Huber studied the proceedings of the
common wasp in the manner which has been so successful in observing
bees--by means of glazed hives, and other contrivances. In this, these
naturalists were greatly aided by the extreme affection of wasps for
their young; for though their nest is carried off, or even cut in
various directions, and exposed to the light, they never desert it, nor
relax their attention to their progeny. When a wasp's nest is removed
from its natural situation, and covered with a glass hive, the first
operation of the inhabitants is to repair the injuries it has suffered.
They carry off with surprising activity all the earth or other matters
which have fallen by accident into the nest; and when they have got it
thoroughly cleared of everything extraneous, they begin to secure it
from further derangement, by fixing it to the glass with papyraceous
columns, similar to those which we have already described. The
breaches which the nest may have suffered are then repaired, and the
thickness of the walls is augmented, with the design, perhaps, of more
effectually excluding the light.
* * * * *
The nest of the hornet is nearly the same in structure with that of
the wasp; but the materials are considerably coarser, and the columns
to which the platforms of cells are suspended are larger and stronger,
the middle one being twice as thick as any of the others. The hornet,
also, does not build underground, but in the cavities of trees, or in
the thatch or under the eaves of barns. Réaumur once found upon a wall
a hornet's nest which had not been long begun, and had it transferred
to the outside of his study-window; but in consequence, as he imagined,
of the absence of the foundress-hornet at the time it was removed, he
could not get the other five hornets, of which the colony consisted,
either to add to the building or repair the damages which it had
sustained.
[Illustration: Hornet's Nest in its first stage.]
M. Réaumur differs from our English naturalists, White, and Kirby
and Spence, with respect to the materials employed by the hornet for
building. The latter say that it employs decayed wood; the former, that
it uses the bark of the ash-tree, but takes less pains to split it
into fine fibres than wasps do; not, however, because it is destitute
of skill; for in constructing the suspensory columns of the platforms,
a paste is prepared little inferior to that made by wasps. We cannot,
from our own observations, decide which of the above statements is
correct, as we have only once seen a hornet procuring materials, at
Compton-Bassett, in Wiltshire; and in that case it gnawed the inner
bark of an elm which had been felled for several months, and was,
consequently, dry and tough. Such materials as this would account for
the common yellowish-brown colour of a hornet's nest. (J. R.)
[Illustration]
[The accompanying figure represents a completed hornet's nest as it
appears when suspended from a beam. Hornets often choose for their
home the space between the roof and the ceiling of summer-houses,
and the nests that are made in such localities are mostly large and
handsome. The reader should notice the blisters by means of which the
insect enlarges its habitation.]
When hornets make choice of a tree for their domicile, they select one
which is in a state of decay, and already partly hollowed; but they
possess the means, in their sharp and strong mandibles, of extending
the excavation to suit their purposes; and Réaumur frequently witnessed
their operations in mining into a decayed tree, and carrying off what
they had gnawed. He observed, also, that in such cases they did not
make use of the large hole of the tree for an entrance, but went to
the trouble of digging a gallery, sufficient for the passage of the
largest hornet in the nest, through the living and undecayed portion of
the tree. As this is perforated in a winding direction, it is no doubt
intended for the purpose of protecting the nest from the intrusion of
depredators, who could more easily effect an entrance if there were not
such a tortuous way to pass through.
[Illustration: Hornet's Nest in a hollow tree.]
[Here is an illustration of a hornet's nest as it appears in the hollow
of a tree. Industrious as is this insect, it never takes needless
trouble, and alters its nest according to circumstances. As has already
been seen, the combs are defended by a complete cover when the nest is
placed in an open situation. But when it is built in the hollow of a
tree there is no cover at all, the insect evidently knowing that the
wooden wall with which the cells are surrounded, affords a sufficient
protection. In cases where a cover is made, the hornets do not form
only a single entrance, as is the case with the wasp, but have a large
number of small entrances in different parts of the wall. Some of these
entrances can be seen in the illustration on page 93.
Hornets are in one sense more industrious than wasps. When night falls,
the wasps betake themselves to their home, and sleep throughout the
night. But, if the moon be up, the hornet is sure to work throughout
the entire night, and will often do so, even when no moon is visible.]
* * * * *
One of the most remarkable of our native social wasps is the tree-wasp
(_Vespa Britannica_), which is not uncommon in the northern, but is
seldom to be met with in the southern parts of the island. Instead of
burrowing in the ground like the common wasp (_Vespa vulgaris_), or
in the hollows of trees like the hornet (_Vespa crabro_), it boldly
swings its nest from the extremity of a branch, where it exhibits
some resemblance, in size and colour, to a Welsh wig hung out to
dry. We have seen more than one of these nests on the same tree, at
Catrine, in Ayrshire, and at Wemyss Bay, in Renfrewshire. The tree
which the Britannic wasp prefers is the silver fir, whose broad flat
branch serves as a protection to the suspended nest both from the
sun and the rain. We have also known a wasp's nest of this kind in a
gooseberry-bush, at Red-house Castle, East Lothian. The materials and
structure are nearly the same as those employed by the common wasp, and
which we have already described. (J. R.)
[We have before us a beautiful example of a nest made by this species
of wasp. There are no less than three consecutive coverings quite
entire, while another is about three-fourths completed, and a fifth is
just begun. The illustration exhibits a very perfect specimen.]
[Illustration]
A singular nest of a species of wasp is figured by Réaumur, but is
apparently rare in this country, as Kirby and Spence mention only a
single nest of similar construction, found in a garden at East-Dale.
This nest is of a flattened globular figure, and composed of a great
number of envelopes, so as to assume a considerable resemblance to a
half-expanded Provence rose. The British specimen mentioned by Kirby
and Spence had only one platform of cells; Réaumur had two; but there
was a large vacant space, which would probably have been filled with
cells, had the nest not been taken away as a specimen. The whole nest
was not much larger than a rose, and was composed of paper exactly
similar to that employed by the common ground-wasp.[X]
[This is probably the nest of _V. rufa_. We possess several specimens
of the nest, one of which corresponds tolerably closely with the
edifice described in the work.]
[Illustration: Wasp's Nest.]
There is another species of social-wasp (_Epipone nidulans_, Latr.)
meriting attention from the singular construction of its nest. It forms
one or more terraces of cells, similar to those of the common wasp,
but without the protection of an outer wall, and quite exposed to the
weather. Swammerdam found a nest of this description attached to the
stem of a nettle. Réaumur says that they are sometimes attached to the
branch of a thorn or other shrub, or to stalks of grass;--peculiarities
which prove that there are several species of these wasps.
[Illustration: Wasps' Cells attached to a Branch.]
The most remarkable circumstance in the architecture of this species
of vespiary is, that it is not horizontal, like those formerly
described, but nearly vertical. The reason appears to be, that if it
had been horizontal, the cells must have been frequently filled with
rain; whereas, in the position in which it is placed, the rain runs
off without lodging. It is, besides, invariably placed so as to face
the north or the east, and consequently is less exposed to rains,
which most frequently come with southerly or westerly winds. It is
another remarkable peculiarity, that, unlike the nests of other wasps,
it is covered with a shining coat of varnish, to prevent moisture
from soaking into the texture of the wasp's paper. The laying on
this varnish, indeed, forms a considerable portion of the labour of
the colony, and individuals may be seen employed for hours together
spreading it on with their tongues.
[Illustration: Comb of Polistes.]
[There is a genus of foreign hymenoptera, called _Polistes_, which
is remarkable for the building powers possessed by its members. The
accompanying illustration is taken from a nest in the British Museum,
and is given of the natural size. The cells are not hexagonal, like
those of the _Epipone_, but are roundish in form. Those in the centre
assume a roughly hexagonal form by pressure, but those which form the
circumference of the cell-group are nearly round, especially on their
outer sides. The cells are not of uniform width, but are narrower at
the base than at the mouth, thus causing the group to assume the form
which is seen in the illustration. This curious group of cells was
brought from Bareilly, in the East Indies, and in the same collection
there are several other specimens, varying considerably both in shape
and size.]
Few circumstances are more striking, with regard to insects, as Kirby
and Spence justly remark, than the great and incessant labour which
maternal affection for their progeny leads them to undergo. Some of
these exertions are so disproportionate to the size of the insect,
that nothing short of ocular conviction could attribute them to such
an agent. A wild bee, or a wasp, for instance, as we have seen, will
dig a hole in a hard bank of earth some inches deep, and five or six
times its own size, labouring unremittingly at this arduous task for
several days in succession, and scarcely allowing itself a moment for
eating or repose. It will then occupy as much time in searching for a
store of food; and no sooner is this finished, than it will set about
repeating the process, and, before it dies, will have completed five or
six similar cells, or even more.
We shall have occasion more particularly to dwell upon the geometrical
arrangement of the cells, both of the wasp and of the social-bee,
in our description of those interesting operations, which have long
attracted the notice, and commanded the admiration of mathematicians
and naturalists. A few observations may here be properly bestowed upon
the _material_ with which the wasp-family construct the interior of
their nests.
The wasp is a paper-maker, and a most perfect and intelligent one.
While mankind were arriving, by slow degrees, at the art of fabricating
this valuable substance, the wasp was making it before their eyes, by
very much the same process as that by which human hands now manufacture
it with the best aid of chemistry and machinery. While some nations
carved their records on wood, and stone, and brass, and leaden
tablets,--others, more advanced, wrote with a style on wax,--others
employed the inner bark of trees, and others the skins of animals
rudely prepared,--the wasp was manufacturing a firm and durable paper.
Even when the papyrus was rendered more fit, by a process of art, for
the transmission of ideas in writing, the wasp was a better artisan
than the Egyptians; for the early attempts at paper-making were so
rude, that the substance produced was almost useless, from being
extremely friable. The paper of the papyrus was formed of the leaves
of the plant, dried, pressed, and polished; the wasp alone knew how
to reduce vegetable fibres to a pulp, and then unite them by a size
or glue, spreading the substance out into a smooth and delicate leaf.
This is exactly the process of paper-making. It would seem that the
wasp knows, as the modern paper-makers now know, that the fibres of
rags, whether linen or cotton, are not the only materials that can be
used in the formation of paper; she employs other vegetable matters,
converting them into a proper consistency by her assiduous exertions.
In some respects she is more skilful even than our paper-makers, for
she takes care to retain her fibres of sufficient length, by which she
renders her paper as strong as she requires. Many manufacturers of
the present day cut their material into small bits, and thus produce
a rotten article. One great distinction between good and bad paper is
its toughness; and this difference is invariably produced by the fibre
of which it is composed being long, and therefore tough; or short, and
therefore friable.
The wasp has been labouring at her manufacture of paper from her first
creation, with precisely the same instruments and the same materials;
and her success has been unvarying. Her machinery is very simple,
and therefore it is never out of order. She learns nothing, and she
forgets nothing. Men, from time to time, lose their excellence in
particular arts, and they are slow in finding out real improvements.
Such improvements are often the effect of accident. Paper is now
manufactured very extensively by machinery in all its stages; and
thus, instead of a single sheet being made by hand, a stream of
paper is poured out, which would form a roll large enough to extend
round the globe, if such a length were desirable. The inventors of
this machinery, Messrs. Fourdrinier, it is said, spent the enormous
sum of 40,000_l._. in vain attempts to render the machine capable
of determining with precision the width of the roll; and, at last,
accomplished their object, at the suggestion of a bystander, by
a strap revolving upon an axis, at a cost of three shillings and
sixpence. Such is the difference between the workings of human
knowledge and experience, and those of animal instinct. We proceed
slowly and in the dark, but our course is not bounded by a narrow
line, for it seems difficult to say what is the perfection of any art;
animals go clearly to a given point--but they can go no further. We
may, however, learn something from their perfect knowledge of what is
within their range. It is not improbable that if man had attended in an
earlier state of society to the labours of wasps, he would have sooner
known how to make paper. We are still behind in our arts and sciences,
because we have not always been observers. If we had watched the
operations of insects, and the structure of insects in general, with
more care, we might have been far advanced in the knowledge of many
arts which are yet in their infancy, for nature has given us abundance
of patterns. We have learnt to perfect some instruments of sound by
examining the structure of the human ear; and the mechanism of an eye
has suggested some valuable improvements in achromatic glasses.
Réaumur has given a very interesting account of the wasps of Cayenne
(_Chartergus nidulans_), which hang their nests in trees.[Y] Like
the bird of Africa called the social grosbeak (_Loxia socia_), they
fabricate a perfect house, capable of containing many hundreds of
their community, and suspend it on high out of the reach of attack.
But the Cayenne wasp is a more expert artist than the bird. He is
a pasteboard-maker;--and the card with which he forms the exterior
covering of his abode is so smooth, so strong, so uniform in its
texture, and so white, that the most skilful manufacturer of this
substance might be proud of the work. It takes ink admirably.
The nest of the pasteboard-making wasp is impervious to water. It hangs
upon the branch of a tree, as represented in the engraving; and those
rain-drops which penetrate through the leaves never rest upon its hard
and polished surface. A small opening for the entrance of the insects
terminates its funnel-shaped bottom. It is impossible to unite more
perfectly the qualities of lightness and strength.
[Illustration: Nest of the Pasteboard-maker Wasp, with part removed to
show the arrangement of the Cells.]
In the specimen from which we take our description, the length of
which is nine inches, six stout circular platforms stretch internally
across, like so many floors, and fixed all round to the walls of the
nest. They are smooth above, with hexagonal cells on the under surface.
These platforms are not quite flat, but rather concave above, like a
watch-glass reversed; the centre of each platform is perforated for
the admission of the wasps, at the extremity of a short funnel-like
projection, and through this access is gained from story to story. On
each platform, therefore, can the wasps walk leisurely about attending
to the pupæ secured in the cells, which, with the mouths downward,
cover the ceiling above their heads--the height of the latter being
just convenient for their work.
[Unlike the habitations made by the British wasps, and which are
vacated annually, this nest is permanent, and serves for several
successive seasons. Of course, it must be enlarged continually, so
as to accommodate an ever-increasing number of inhabitants. The mode
of enlarging is sufficiently curious. The British wasps enlarge
their nests either by making a larger covering and then removing the
smaller, or by raising blisters on the outside, and eating away beneath
them. But the pendulous wasp of Brazil proceeds on just the opposite
principle, making new cells first, and covering them afterwards. The
new tier of cells is set on the bottom of the nest, which thus becomes
the floor of that tier, and a new bottom is then made beneath these new
cells.]
Pendent wasps' nests of enormous size are found in Ceylon, suspended
often in the talipot-tree at the height of seventy feet. The appearance
of these nests thus elevated, with the larger leaves of the tree,
used by the natives as umbrellas and tents, waving over them, is very
singular. Though no species of European wasp is a storer of honey,
yet this rule does not apply to certain species of South America. In
the 'Annals and Magazine of Natural History' for June, 1841, will be
found a detailed account, with a figure, of the pendent nest of a
species termed by Mr. A. White _Myrapetra scutellaris_. The external
case consists of stout cardboard covered with conical knobs of various
sizes. The entrances are artfully protected by pent-roofs from the
weather and heavy rains; and are tortuous, so as to render the ingress
of a moth or other large insect difficult. Internally are fourteen
combs, exclusive of a globular mass, the nucleus of several circular
combs, which are succeeded by others of an arched form--that is,
constituting segments of circles. Many of the uppermost combs were
found to have the cells filled with honey of a brownish-red colour, but
which had lost its flavour. After entering into some minute details,
Mr. A. White makes the following interesting observations:--"Azara,
in the account of his residence in various parts of South America,
mentions the fact of _several wasps_ of these countries collecting
honey. The Baron Walchenaer, who edited the French translation of
this work, published in 1809, thought that the Spanish traveller, who
was unskilled in entomology, had made some mistake with regard to
the insects, and regarded the so-called _wasps_ as belonging to some
_bee_ of the genus of which _Apis amalthea_ is the type (_Melipona_).
Latreille (who afterwards corrected his mistake) also believed that
they must be referred to the genera _Melipona_ or _Trigona_--insects
which in South America take the place of our honey-bee. These authors
were afterwards clearly convinced of the correctness of Azara's
observations, by the circumstance of M. Auguste de St. Hilaire finding
near the river Uruguay an oval grey-coloured nest of a papery
consistence, like that of the European wasps, suspended from the
branches of a small shrub about a foot from the ground: he and two
other attendants partook of some honey (contained in its cells) and
found it of an agreeable sweetness, free from the pharmaceutic taste
which so frequently accompanies European honey. He gives a detailed
account of its poisonous effects on himself and his two men. Afterwards
he procured specimens of the wasp, which was described by Latreille
under the name of _Polistes Lecheguana_."
[Illustration: Nest of Myrapetra.]
[The accompanying illustration shows this remarkable nest, both as it
appears externally, and when divided vertically.
The material is probably the dung of the Capincha, an animal allied
to the guinea-pig and the agouti. The natives, at all events, state
that such is the case, and the aspect of the nest as seen through a
magnifying glass carries out this assertion. The nest is hung to a
branch, and is seldom more than four feet from the ground. The insect
is a very little one in comparison with the size of the nest, which is
sixteen inches in length, and twelve in width. The largest specimens of
this insect are only one third of an inch long, while the generality
scarcely exceed a quarter of an inch. Its colour is brown.
In the section is shown the very peculiar shape of the combs. At the
upper part is seen the globular centre, surrounded with a comb that
completely encircles it. Other combs follow in order, but are less
curved as they approach the bottom of the nest. The insects obtain
admission to the several tiers by means of apertures which are left
between the extremities of the comb and the wall of the nest. The combs
are made of the same material as the outer wall, but are very thin and
paper-like. This nest may be seen in the British Museum.]
It would seem that the nest described by Mr. White agrees with that
of a wasp termed _Chiguana_ by Azara (or _Lecheguana_), and is very
different to the slight papery nest of the _Polistes Lecheguana_ of
Latreille. We may add that M. Auguste de St. Hilaire speaks of two
species of wasps remarkable for storing honey in South America; the
honey of one is white, of the other reddish. That the habits of these
honey-wasps must differ considerably from those of any of our European
species we may at once admit; perhaps in some points of their economy
these insects may approach the bee.
[In the same country as is inhabited by the _Myrapetra_, and in
much the same localities, is sometimes found the nest of another
honey-making wasp, called _Nectarinia analis_, a small and plainly-clad
insect. It is hung to the branches of low trees and underwood, and
often includes both twigs and leaves in its structure. The combs of
this insect are greatly curved, in order to suit the shape of the
general covering, but are not arranged with that beautiful regularity
which distinguishes those of the _Myrapetra_. A specimen of this nest
may be seen in the British Museum, and as the outer covering has been
partially taken away, the observer will be enabled to note the general
form of the combs and the structure of the cells.
In the accompanying illustration are shown the habitations of two
remarkable insects, both belonging to the _Hymenoptera_. Indeed, the
greater number of pensile nests made by insects are formed by members
of this important order; and, if we were to exclude all the wasps,
bees, and ants, we should find that we had excluded about ninety per
cent. of the pensile architects.
The left-hand figure represents a nest made by a species of _Polybia_,
inhabiting Brazil. It is made of a papery kind of substance, of rather
slight texture, and is fixed to the stalk of a reed. The outside of the
nest is seen to be marked with a series of horizontal ribs. These show
the progressive stages of the nest, each rib marking a layer of paper
as it was spread by the insect builder. The combs extend throughout the
entire nest, the largest occupying the centre, and the smallest the
ends. Each comb is firmly supported by a footstalk, which is fixed, not
to the upper tier of cells, as is the case with the British wasps, but
to the reed on which the nest is built.
Other species of _Polybia_ build nests different in shape and
arrangement, though still of the pensile character. One species builds
a nearly globular nest, made in a rather curious manner. Carrying out
still farther the principle on which the cardboard wasp enlarges its
nest, the _Polybia_ entirely covers the outer wall with cells, and
then makes a new wall over them. When a nest has reached a tolerable
size, it is composed of a whole series of concentric combs, the roof of
each having been originally the outer wall of the nest. There are in
the British Museum some admirable specimens of these nests, in some of
which the process of enlargement can be very clearly traced. Patches of
new cells are seen upon the external covering, while a few breaches in
the structure show the concentric combs.
[Illustration: Nests of Polybia.]
One very curious point about these cells is, that they are not uniform
in their direction, as is generally the case with those of social
hymenoptera. The greater part, such as the various wasps, hornets, and
their kin, have the mouths of the cells downwards, while the cells of
the hive-bee are nearly horizontal. But the cells of this insect are
arranged without the least regard to their position, all the bases
pointing towards the centre of the nest, and all the mouths radiating
outwards.
[Illustration: Nests of Synæca and Polybia.]
There seems to be scarcely any bound to the variety which exists in the
nests of the social hymenoptera. The insect which makes the nest which
is represented in the illustration is a native of Brazil, and is known
to entomologists as _Synæca cyanea_. The first of these names is given
to it on account of its social habits, and the second, in reference to
the bluish colour of its body. It is rather larger than the preceding
insects, being about three quarters of an inch in length. Its wings are
brown.
The shape and size of the nest are exceedingly variable, but it is
almost invariably longer than wide, and is fixed to a branch or some
similar object. Sometimes it attains considerable dimensions, and has
been known to measure a full yard in length. Yet, however large it may
be, there is only a single comb, which is set upon the side of the nest
next the branch, and, in consequence, has almost all its cells placed
in a horizontal direction. In the illustration, the right-hand figure
represents the external appearance of the nest, and the central figure
shows the manner in which the single comb is set upon the branch. The
nest which occupies the left hand of the illustration is made by a
species of _Polybia_, and is here given in order to show a remarkable
example of similarity in the mode of building adopted by two different
insects. In the one case, however, the cells are all fastened by their
bases to the branch, but in the other the cells are attached to one
common base which is prolonged into a footstalk.
There have been lately discovered some very remarkable social nests.
Specimens of both these nests may be seen in the entomological
department of the museum at Oxford.
The first is formed very much like a rather flattened Florence flask,
and is hung by the neck from the branch of a tree. It is made of a
strong, parchment-like substance, formed by innumerable silken threads
woven and matted together into a kind of felt. When it was cut open a
most singular sight was exhibited. Nearly the whole of the interior
was covered with the pupæ of some butterfly, all hanging by their
tails, and many of them suspended to a twig which projected downwards
into the nest. Although the nest is barely eight inches in length, a
great proportion of which is taken up by the neck, about one hundred
pupæ were found in it. At the bottom of the nest is a small and nearly
circular aperture, through which the insects could make their way as
soon as they escaped from the pupal envelope, and before their wings
became extended and hardened.
The butterfly which makes this singular nest is a native of Mexico, and
is named _Eucheira socialis_. The colour of its wings is dark brown,
with an ill-defined white band across them.
The second nest was brought from tropical Africa, and is remarkable
for another peculiarity. It is shaped much like a cushion, and its
measurements are, eight inches in length, five and a half in breadth,
and three in depth. Instead of having only one place of exit for the
inmates, it has thirteen or fourteen, all formed in the same manner. A
number of short, stiff, and almost bristly threads are set round the
apertures, their ends all projecting outwards, and converging to a
point, where they all meet and even slightly cross each other. Owing to
this structure, it is easy enough for any of the insects to pass out,
as the converging hairs yield to the pressure, whereas they form an
effectual barrier against any insect that wishes to creep into the nest.
The material of the nest is very strong and hard, and is formed of two
layers, the inner being made of smooth brown silk, and the outer of
harsher and stronger orange silk threads.]
_CHAPTER V._
ARCHITECTURE OF THE HIVE-BEE.
[Illustration: Part of a Honeycomb, and Bees at work.]
Although the hive-bee (_Apis mellifica_) has engaged the attention
of the curious from the earliest ages, recent discoveries prove that
we are yet only beginning to arrive at a correct knowledge of its
wonderful proceedings. Pliny informs us that Astromachus, of Soles, in
Cilicia, devoted fifty-eight years to the study; and that Philiscus the
Thracian spent his whole life in forests for the purpose of observing
them. But in consequence (as we may naturally infer) of the imperfect
methods of research, assuming that what they did discover was known to
Aristotle, Columella, and Pliny, we are justified in pronouncing the
statements of these philosophers, as well as the embellished poetical
pictures of Virgil, to be nothing more than conjecture, almost in every
particular erroneous. It was not indeed till 1711, when glass hives
were invented by Maraldi, a mathematician of Nico, that what we may
call the in-door proceedings of bees could be observed. This important
invention was soon afterwards taken advantage of by M. Réaumur, who
laid the foundation of the more recent discoveries of John Hunter,
Schirach, and the Hubers. The admirable architecture which bees
exhibit in their miniature cities has, by these and other naturalists,
been investigated with great care and accuracy. We shall endeavour
to give as full an account of the wonderful structures as our limits
will allow. In this we shall chiefly follow M. Huber the elder, whose
researches appear almost miraculous when we consider that he was blind.
At the early age of seventeen this remarkable man lost his sight by
_gutta serena_, the "drop serene" of our own Milton. But though cut off
from the sight of Nature's works, he dedicated himself to their study.
He saw them through the eyes of the admirable woman whom he married;
his philosophical reasonings pointed out to her all that he wanted to
ascertain; and as she reported to him from time to time the results
of his ingenious experiments, he was enabled to complete, by diligent
investigation, one of the most accurate and satisfactory accounts of
the habits of bees which had ever been produced.
It had long been known that the bees of a hive consist of three sorts,
which was ascertained by M. Réaumur to be distinguished as workers or
neuters, constituting the bulk of the population; drones or males, the
least numerous class; and a single female, the queen and mother of
the colony. Schirach subsequently discovered the very extraordinary
fact, which Huber and others have proved beyond doubt, that when a
hive is accidentally deprived of a queen, the grub of a worker can be
and is fed in a particular manner so as to become a queen and supply
the loss.[Z] But another discovery of M. Huber is of more importance
to the subject of architecture now before us. By minute research he
ascertained that the workers which had been considered by former
naturalists to be all alike, are divided into two important classes,
nurse-bees and wax-makers.
The _nurse-bees_ are rather smaller than the wax-workers, and even
when gorged with honey their belly does not, as in the others, appear
distended. Their business is to collect honey, and impart it to their
companions; to feed and take care of the young grubs, and to complete
the combs and cells which have been founded by the others; but they are
not charged with provisioning the hive.
The _wax-workers_, on the other hand, are not only a little larger,
but their stomach, when gorged with honey, is capable of considerable
distension, as M. Huber proved by repeated experiments. He also
ascertained that neither of the varieties can alone fulfil all the
functions shared among the workers of a hive. He painted those of each
class with different colours, in order to study their proceedings,
and their labours were not interchanged. In another experiment, after
supplying a hive deprived of a queen with brood and pollen, he saw the
nurse-bees quickly occupied in the nutrition of the grubs, while those
of the wax-working class neglected them. When hives are full of combs,
the wax-workers disgorge their honey into the ordinary magazines,
making no wax; but if they want a reservoir for its reception, and if
their queen does not find cells ready made wherein to lay her eggs,
they retain the honey in the stomach, and in twenty-four hours they
produce wax. Then the labour of constructing combs begins.
It might perhaps be supposed that, when the country does not afford
honey, the wax-workers consume the provision stored up in the hive. But
they are not permitted to touch it. A portion of honey is carefully
preserved, and the cells containing it are protected by a waxen
covering, which is never removed except in case of extreme necessity,
and when honey is not to be otherwise procured. The cells are at
no time opened during summer; other reservoirs, always exposed,
contribute to the daily use of the community; each bee, however,
supplying itself from them with nothing but what is required for
present wants. Wax-workers appear with large bellies at the entrance of
their hive only when the country affords a copious collection of honey.
From this it may be concluded that the production of the waxy matter
depends on a concurrence of circumstances not invariably subsisting.
Nurse-bees also produce wax, but in a very inferior quantity to what
is elaborated by the real wax-workers. Another characteristic whereby
an attentive observer can determine the moment of bees collecting
sufficient honey to produce wax, is the strong odour of both these
substances from the hive, which is not equally intense at any other
time. From such data, it was easy for M. Huber to discover whether
the bees worked in wax in his own hives, and in those of the other
cultivators of the district.
There is still another sort of bee, first observed by Huber in 1809,
which appear to be only casual inmates of the hive, and which are
driven forth to starve, or are killed in conflict. They closely
resemble the ordinary workers, but are less hairy, and of a much darker
colour. These have been called _black bees_, and are supposed by Huber
to be defective bees;[AA] but Kirby and Spence conjecture that they are
toil-worn superannuated workers, of no further use, and are therefore
sacrificed, because burdensome to a community which tolerates no
unnecessary inmates.
Preparation of Wax.
In order to build the beautiful combs, which every one must
have repeatedly seen and admired, it is indispensable that the
architect-bees should be provided with the materials--with the wax,
in short, of which they are principally formed. Before we follow
them, therefore, to the operation of building, it may be necessary
to inquire how the wax itself is procured. Here the discoveries of
recent inquirers have been little less singular and unexpected than
in other departments of the history of these extraordinary insects.
Now that it has been proved that wax is secreted by bees, it is not a
little amusing to read the accounts given by our elder naturalists, of
its being collected from flowers. Our countryman, Thorley,[AB] appears
to have been the first who suspected the true origin of wax, and
Wildman (1769) seems also to have been aware of it; but Réaumur, and
particularly Bonnet, though both of them in general shrewd and accurate
observers, were partially deceived by appearances.
The bees, we are erroneously told, search for wax "upon all sorts of
trees and plants, but especially the rocket, the simple poppy, and
in general all kinds of flowers. They amass it with their hair, with
which their whole body is invested. It is something pleasant to see
them roll in the yellow dust which falls from the chives to the bottom
of the flowers, and then return covered with the same grains; but
their best method of gathering the wax, especially when it is not very
plentiful, is to carry away all the little particles of it with their
jaws and fore feet, to press the wax upon them into little pellets,
and slide them one at a time, with their middle feet, into a socket or
cavity, that opens at their hinder feet, and serves to keep the burthen
fixed and steady till they return home. They are sometimes exposed to
inconveniences in this work by the motion of the air, and the delicate
texture of the flowers, which bend under their feet and hinder them
from packing up their booty, on which occasions they fix themselves in
some steady place, where they press the wax into a mass, and wind it
round their legs, making frequent returns to the flowers; and when they
have stocked themselves with a sufficient quantity, they immediately
repair to their habitation. Two men, in the compass of a whole day,
could not amass so much as two little balls of wax; and yet they are no
more than the common burthen of a single bee, and the produce of one
journey. Those who are employed in collecting the wax from flowers
are assisted by their companions, who attend them at the door of the
hive, ease them of their load at their arrival, brush their feet, and
shake out the two balls of wax; upon which the others return to the
fields to gather new treasure, while those who disburthened them convey
their charge to the magazine. But some bees, again, when they have
brought their load home, carry it themselves to the lodge, and there
deliver it, laying hold of one end by their hinder feet, and with their
middle feet sliding it out of the cavity that contained it; but this
is evidently a work of supererogation which they are not obliged to
perform. The packets of wax continue a few moments in the lodge, till
a set of officers come, who are charged with a third commission, which
is to knead this wax with their feet, and spread it out into different
sheets, laid one above another. This is the unwrought wax, which is
easily distinguished to be the produce of different flowers, by the
variety of colours that appear on each sheet. When they afterwards
come to work, they knead it over again; they purify and whiten, and
then reduce it to a uniform colour. They use this wax with a wonderful
frugality; for it is easy to observe that the whole family is conducted
by prudence, and all their actions regulated by good government.
Everything is granted to necessity, but nothing to superfluity; not
the least grain of wax is neglected, and if they waste it, they are
frequently obliged to provide more; at those very times when they want
to get their provision of honey, they take off the wax that closed the
cells, and carry it to the magazine."[AC]
Réaumur hesitated in believing that this was a correct view of the
subject, from observing the great difference between wax and pollen;
but he was inclined to think the pollen might be swallowed, partially
digested, and disgorged in the form of a kind of paste. Schirach also
mentions, that it was remarked by a certain Lusatian, that wax comes
from the rings of the body, because, on withdrawing a bee while it is
at work, and extending its body, the wax may be seen there in the form
of scales.
The celebrated John Hunter shrewdly remarked that the pellets of pollen
seen on the thighs of bees are of different colours on different bees,
while the shade of the new-made comb is always uniform; and therefore
he concluded that pollen was not the origin of wax. Pollen also, he
observed, is collected with greater avidity for old hives, where the
comb is complete, than for those where it is only begun, which would
hardly be the case were it the material of wax. He found that when the
weather was cold and wet in June, so that a young swarm was prevented
from going abroad, as much comb was constructed as had been made in an
equal time when the weather was favourable and fine.
The pellets of pollen on the thighs being thence proved not to be
wax, he came to the conclusion that it was an external secretion,
originating between the plates of the belly. When he first observed
this, he felt not a little embarrassed to explain the phenomenon, and
doubted whether new plates were forming, or whether bees cast their old
ones as lobsters do their shell. By melting the scales, he ascertained
at least that they were wax; and his opinion was confirmed by the fact,
that the scales are only to be found during the season when the combs
are constructed. But he did not succeed in completing the discovery by
observing the bees actually detach the scales, though he conjectured
they might be taken up by others, if they were once shaken out from
between the rings.[AD]
We need not be so much surprised at mistakes committed upon this
subject, when we recollect that honey itself was believed by the
ancients to be an emanation of the air--a dew that descended upon
flowers, as if it had a limited commission to fall only on them. The
exposure and correction of error is one of the first steps to genuine
knowledge; and when we are aware of the stumbling-blocks which have
interrupted the progress of others, we can always travel more securely
in the way of truth.
That wax is secreted is proved both by the wax-pouches within the
rings of the abdomen, and by actual experiment. Huber and others fed
bees entirely upon honey or sugar, and, notwithstanding, wax was
produced and combs formed as if they had been at liberty to select
their food. "When bees were confined," says M. Huber, "for the purpose
of discovering whether honey was sufficient for the production of
wax, they supported their captivity patiently, and showed uncommon
perseverance in rebuilding their combs as we removed them. Our
experiments required the presence of grubs; honey and water had to be
provided; the bees were to be supplied with combs containing brood, and
at the same time it was necessary to confine them, that they might not
seek pollen abroad. Having a swarm by chance, which had become useless
from sterility of the queen, we devoted it for our investigation in one
of my leaf-hives, which was glazed on both sides. We removed the queen,
and substituted combs containing eggs and young grubs, but no cell with
farina; even the smallest particle of the substance which John Hunter
conjectured to be the basis of the nutriment of the young was taken
away.
"Nothing remarkable occurred during the first and second day: the bees
brooded over the young, and seemed to take an interest in them; but at
sunset on the third a loud noise was heard in the hive. Impatient to
discover the reason, we opened a shutter, and saw all in confusion;
the brood was abandoned, the workers ran in disorder over the combs,
thousands rushed towards the lower part of the hive, and those about
the entrance gnawed at its grating. Their design was not equivocal;
they wished to quit their prison. Some imperious necessity evidently
obliged them to seek elsewhere what they could not find in the hive;
and apprehensive that they might perish if I restrained them longer
from yielding to their instinct, I set them at liberty. The whole
swarm escaped, but the hour being unfavourable for their collections,
they flew around the hive, and did not depart far from it. Increasing
darkness and the coolness of the air compelled them very soon to
return. Probably these circumstances calmed their agitation; for
we observed them peaceably remounting their combs; order seemed
re-established, and we took advantage of this moment to close the hive.
"Next day, the 19th of July, we saw the rudiments of two royal cells,
which the bees had formed on one of the brood-combs. This evening, at
the same hour as on the preceding, we again heard a loud buzzing in
the closed hive; agitation and disorder rose to the highest degree,
and we were again obliged to let the swarm escape. The bees did not
remain long absent from their habitation; they quieted and returned
as before. We remarked on the 20th that the royal cells had not been
continued, as would have been the case in the ordinary state of
things. A great tumult took place in the evening; the bees appeared to
be in a delirium; we set them at liberty, and order was restored on
their return. Their captivity having endured five days, we thought it
needless to protract it farther; besides, we were desirous of knowing
whether the brood was in a suitable condition, and if it had made the
usual progress; and we wished also to try to discover what might be
the cause of the periodical agitation of the bees. M. Burnens (the
assistant of Huber), having exposed the two brood-combs, the royal
cells were immediately recognised; but it was obvious that they had
not been enlarged. Why should they? Neither eggs, grubs, nor that kind
of paste peculiar to the individuals of their species were there! The
other cells were vacant likewise; no brood, not an atom of paste, was
in them. Thus, the worms had died of hunger. Had we precluded the bees
from all means of sustenance by removing the farina? To decide this
point, it was necessary to confide other brood to the care of the
same insects, now giving them abundance of pollen. They had not been
enabled to make any collections while we examined their combs. On this
occasion they escaped in an apartment where the windows were shut; and
after substituting young worms for those they had allowed to perish,
we returned them to their prison. Next day we remarked that they had
resumed courage; they had consolidated the combs, and remained on the
brood. They were then provided with fragments of combs, where other
workers had stored up farina; and to be able to observe what they did
with it, we took this substance from some of their cells, and spread
it on the board of the hive. The bees soon discovered both the farina
in the combs and what we had exposed to them. They crowded to the
cells, and also descending to the bottom of the hives, took the pollen
grain by grain in their teeth, and conveyed it to their mouths. Those
that had eaten it most greedily mounted the combs before the rest,
and stopping on the cells of the young worms, inserted their heads,
and remained there for a certain time. M. Burnens opened one of the
divisions of the hive gently, and powdered the workers, for the purpose
of recognising them when they should ascend the combs. He observed them
during several hours, and by this means ascertained that they took
so great a quantity of pollen only to impart it to their young. Then
withdrawing the portions of comb which had been placed by us on the
board of the hive, we saw that the pollen had been sensibly diminished
in quantity. They were returned to the bees, to augment their provision
still further, for the purpose of extending the experiment. The royal,
as well as several common, cells were soon closed; and, on opening the
hive, all the worms were found to have prospered. Some still had their
food before them; the cells of others that had spun were shut with a
waxen covering.
"We witnessed these facts repeatedly, and always with equal interest.
They so decisively prove the regard of the bees towards the grubs which
they are intrusted with rearing, that we shall not seek for any other
explanation of their conduct. Another fact, no less extraordinary,
and much more difficult to be accounted for, was exhibited by bees
constrained to work in wax, several times successively, from the syrup
of sugar. Towards the close of the experiment they ceased to feed the
young, though in the beginning these had received the usual attention.
They even frequently dragged them from their cells, and carried them
out of the hive."[AE]
Mr. Wiston, of Germantown, in the United States, mentions a fact
conclusive on this subject. "I had," says he, "a late swarm last
summer, which, in consequence of the drought, filled only one box with
honey. As it was late in the season, and the food collected would not
enable the bees to subsist for the winter, I shut up the hive, and gave
them half-a-pint of honey every day. They immediately set to work,
filled the empty cells, and then constructed new cells enough to fill
another box, in which they deposited the remainder of the honey."
A more interesting proof is thus related by the same gentleman: "In the
summer of 1824, I traced some wild bees, which had been feeding on the
flowers in my meadow, to their home in the woods, and which I found in
the body of an oak-tree, exactly fifty feet above the ground. Having
caused the entrance to the hive to be closed by an expert climber,
the limbs were separated in detail, until the trunk alone was left
standing. To the upper extremity of this, a tackle-fall was attached so
as to connect it with an adjacent tree, and, a saw being applied below,
the naked trunk was cut through. When the immense weight was lowered
nearly to the earth, the ropes broke, and the mass fell with a violent
crash. The part of the tree which contained the hive, separated by the
saw, was conveyed to my garden, and placed in a vertical position. On
being released, the bees issued out by thousands, and though alarmed,
soon became reconciled to the change of situation. By removing a part
of the top of the block the interior of the hive was exposed to view,
and the comb itself, nearly six feet in height, was observed to have
fallen down two feet below the roof of the cavity. To repair the
damage was the first object of the labourers: in doing which, a large
part of their store of honey was expended, because it was at too late
a season to obtain materials from abroad. In the following February
these industrious but unfortunate insects issuing in a confused manner
from the hive, fell dead in thousands around its entrance, the victims
of a poverty created by their efforts to repair the ruins of their
habitation."[AF]