Every one knows the wasps as a race of dangerous brigands which live by
rapine, are incessantly fighting battles, and which exist only to do
harm. However, wasps, like Figaro, are better than they are reputed to
be. Their societies are admirably organised; their nests are models of
industry and artistic fancy. They have even certain domestic virtues
which deserve our esteem; only they are an excitable race it is well not
to cross. If great heat adds to their natural irritability, they
savagely attack those who annoy them, and pursue them to a distance. No
one, indeed, is ignorant that their sting is very painful. In cold
weather, and towards night, they are less vivacious and less to be
dreaded.
[Illustration: Fig. 344.--Wasp's Nest.]
The wasps are distinguished from the bees by a decided characteristic.
In a state of repose they fold together their upper wings, which then
seem very narrow, only spreading them out when they are about to fly;
whilst the latter when at rest keep their upper wings spread out.
Wasps live in companies, which last only a year, and are composed of
males, females, and workers. But the female wasp does not pass her
entire life in idleness as a queen, like the mother hive bee. She
occupies herself in making the nest and in taking care of the young,
like the mother humble bee. The males have also their duties. They
watch over the cleanliness of the habitation, and are the sanitary
commissioners and undertakers to the city. These are easily recognised
by their oblong bodies, having so slight a connection with the thorax,
as it were by a thread.
[Illustration: Fig. 345.--Common Wasp (_Vespa vulgaris_).]
[Illustration: Fig. 346.--Bush Wasp (_Vespa norvegica_).]
Their sting is larger than that of the bees, and is supplied with
poison from a pouch placed at its base. The males have no sting. Wasps
do not secrete wax. With their mandibles they scrape wood and plants,
the fragments of which they agglutinate together in such a way as to
form a tough cardboard. Thus, they invented the manufacture of paper
long before men. Charles de Geer, in his celebrated work, sums up the
habits of these insects in the following manner:--"Wasps," says he,
"are, like bees, fond of sweets and honey, although they rarely seek
them in flowers; but their principal food consists in matters of quite
a different kind, such as fruits of all kinds, raw flesh, and live
insects, which they seize and devour. They sometimes do dreadful
damage in bee-hives, devouring the honey, and killing the bees. They
do not gather wax; their nests and their combs are composed of a
matter resembling grey paper, which they get from rotten wood, and
which they scrape off with their jaws; they make a sort of paste of
these scrapings by moistening them with a certain liquid which they
disgorge. The cells in the combs are hexagonal, and very regular, like
those of bees."[99]
[99] "Mémoires pour servir à l'Histoire des Insectes," tome
ii., p. 765. In 4to. Stockholm, 1771.
[Illustration: Fig. 347.--The Hornet (_Vespa crabro_).]
Wasps collect the materials with which they build near the place where
they have chosen to establish their domicile. These materials are
ligneous fibre, mixed up with saliva, with the aid of which these
insects prepare the paper-like substance, which is very tough, and
destined to form the walls of the cells and their exterior covering.
The greater number make their habitation in the ground. Of these is
our Common Wasp (_Vespa vulgaris_), which is black, agreeably
contrasted with bright yellow. The Bush Wasp (_Vespa norvegica_),
which inhabits woods, constructs its nest between the branches of
shrubs or bushes. It is smaller than the common species. The Hornet is
the largest European species of the family of the _Vespidæ_. The
substance of its nest is yellowish, and very fragile, and is
constructed under a roof, in a loft, or in the hole of an old wall,
but most often in the hollow of a decayed tree. Another species of
this family (_Polistes gallica_, Fig. 348) fixes its little nest by a
footstalk to the stem of some plant.
[Illustration: Fig. 348.--Polistes gallica.]
Wasps begin laying in spring, and go on laying all the summer. Each
cell receives one single egg, and, as with bees, the workers' eggs are
the first laid. Eight days after the laying, there comes out of each
egg a larva without feet, and already provided with two mandibles.
These larvæ receive their food in the form of balls, which the
females or the workers knead up with their mandibles and their legs
before presenting to their nurslings, very nearly in the same way as
birds give their beak full of food to their little ones. At the end of
three weeks the larvæ cease to take food, and begin to shut themselves
up in their cells, the interior of which they line with a coating of
silk. In this they change their form, and assume the appearance of the
perfect insect, with its six legs and its wings, but motionless, and
contracted together. A sort of bag keeps all the organs swathed up
together (Fig. 349). This pupa state lasts for eight or nine days, at
the end of which time the insect is fully developed; it casts its
skin, breaks the door of its prison, and launches itself into the air.
A cell is no sooner abandoned than a worker visits, cleans it, and
puts it in a fit state to receive another egg.
[Illustration: Fig. 349.--Pupa of the common wasp.]
During the summer the female wasp remains constantly in the nest,
absorbed with family cares. She is occupied in laying eggs and in
feeding her progeny, with the active assistance of the workers, or
mules, as Réaumur and Charles de Geer call them, because they are
unfruitful.
In the interior of the nests you generally find the most perfectly
good understanding existing, and the most perfect order, in spite of
the warlike instincts of these insects. It is only on rare occasions
that this domestic peace is disturbed by the quarrels of male with
male or worker with worker; but these combats are not deadly. Never,
moreover, has one nest of wasps been known to declare war against
another for the purpose of robbing it. "The government of wasps," says
M. Victor Rendu, "explains very well the gentleness of their public
conduct. Amongst them there are no despots; no one either reigns or
governs; each one lives at liberty in a free city, on the sole
condition of never being a burden to the state. They all act in
concert, without privileges or monopolies, under the influence of a
common law--the great law of the public good, from which no one is
exempted."[100]
[100] "L'Intelligence des Bêtes." In 18mo. Paris, 1864.
But this model republic is fatally doomed to early destruction. At the
approach of winter all the workers, as also the males, perish. Some
pregnant females alone hold out against the cold, and get through the
winter, to propagate and perpetuate their species. Before dying, these
insects destroy all the larvæ which are not hatched at the first
approach of cold weather. In spring the females revive, and begin
alone the construction of a new nest. They then lay workers' eggs,
which are not long in furnishing them a whole regiment of devoted and
active assistants. These traits are pretty nearly the same for the
different species of wasps, the only difference being in the way in
which they build their nests.
[Illustration: Fig. 350.--Exterior of a Wasp's Nest on a branch of a
tree.]
We have already said that the common wasp makes its nest in the
ground. A gallery, of about an inch and a half in diameter, leads to
the nest, situated at a depth which varies from six inches to two
feet. "It is," says Réaumur, "a small subterranean town, which is not
built in the style of ours, but which has a symmetry of its own. The
streets and the dwelling-places are regularly distributed. It is even
surrounded with walls on all sides. I do not give this name to the
side of the hollow in which it is situated; the walls I allude to are
only walls of paper, but strong enough, nevertheless, for the uses for
which they are intended." Generally, the shape of the outside of a
wasp's nest is spherical or oval, sometimes conical. Its diameter is
about from twelve to sixteen inches, its surface, which resembles a
mass of bivalve shells, has one hole for entrance, and another for
exit, just large enough to allow of one single wasp passing in or out
at the same time (Fig. 350).
[Illustration: Fig. 351.--Interior of a Wasp's Nest, after Réaumur.]
The wasps' nest is composed, in the interior, of fifteen or sixteen
horizontal galleries, arranged in storeys, and supported by numerous
pillars of separation. We give here (Fig. 351) a section and view of
the interior, drawn from memory by Réaumur.[101] The cakes forming the
combs are composed of hexagonal cells, which are always used as
cradles, never as storehouses. They open below. The exterior envelope
of the nest is made with leaves of a sort of greyish, very gummy
paper, which is applied layer by layer. Réaumur has given a very
detailed account of the way in which these insects construct their
nests.[102] They collect fibres of wood--which are their raw
material--make them into a sort of coarse lint, which they reduce to
balls, and carry between their legs to the nest. These balls are next
stuck on to the work already begun. Then the insect stretches them
out, flattens them, and draws them into thin layers, as a bricklayer
spreads mortar with his trowel. The wasp works with extreme quickness,
always backwards, so that it may have incessantly before its eyes the
work it has done: the movement of its mandibles is even quicker than
that of its legs.
[101] "Mémoires," tome vi., planche 14, p. 167.
[102] _Ibid_, tome vi., p. 177.
Towards the end of summer the nest may contain 3,000 workers, and many
females, who live together in perfect harmony. The number of males
exceeds that of the females. A female weighs, by herself, as much as
three males or six workers. With the exception of those which are
occupied in building and in taking care of the eggs, all wasps go out
hunting during the day. They are carnivorous, and may be seen
attacking other insects, which they tear to pieces after having
killed, so as to carry the bits to their nests, where thousands of
mouths are clamouring for their food. The wasp pays great attention to
the vines. It penetrates also into the interior of our houses, and
infests the butchers' shops; but this the butchers do not much mind,
for the wasp drives away the flies which would lay their eggs on the
meat and thus contribute to its corruption.
As the winter approaches, the wasps go out less and less, and very
soon cease to do so at all. The greater number then die, huddled up in
their nest. A few females only, as we have said, get through the cold
season. They sleep with their wings and legs folded up, which gives
them the appearance of chrysalides. They can nevertheless sting in
this state, as M. Guérin-Méneville found out to his cost. The spring
wakes them up, and they then found new colonies. "It is at this
season," says M. Maurice Girard, in his book on the "Metamorphoses of
Insects," "that, with a little trouble, it would be easy to diminish
in a very perceptible degree the number of wasps, which are, later, so
destructive to the fruit, by catching in nets the females, which
might be attracted in quantities by means of the blossom of the black
currant." This is a useful hint to gardeners.
The Hornets are distinguished from other wasps by their great size.
They make their nests in the trunks of old trees, perforating the
sound wood to arrive at the heart, which is rotten, or hollowing for
themselves a hole, which they clear out by the gallery which leads to
it. In this hole they construct first a dome suspended to the top by a
footstalk; then a series of combs composed of cells, hanging the first
to this dome, the second to the first, and so on, by stalks or pillars
of a paper-like substance. When fixed under roofs, these insects have
often the form of an elongated pear. Fig. 352 represents one of these
nests, after Réaumur. The societies of hornets contain fewer members
than those of the common wasp; at most 200 insects.
[Illustration: Fig. 352.--Hanging Hornet's Nest.]
The _Polistes_ are a peculiar kind of wasp, smaller than the others,
slender, with the abdomen tapering towards the base. The construction
of their nests is more simple, having no envelopes, as shown in Fig.
353. They attach them to the stems of broom, furze, or other shrubs,
by a footstalk, or pedicle. They are like little paper bouquets,
composed of from twenty to thirty cells, grouped in circle.
[Illustration: Fig. 353.--Nest of _Polistes gallica_.]
[Illustration: Fig. 354.--The Card-making Wasp (_Chartergus
nidulans_).]
The Card-making Wasp of Cayenne (_Chartergus nidulans_, Fig. 354) is a
consummate artist. Its nest represents a sort of box or bag, made of a
substance resembling cardboard, so fine and so white that the best
worker in that material would be deceived by it. This nest has only
one single hole at its base; each of the combs it contains is likewise
pierced by a hole in its centre, to afford a passage to the wasps. In
an architectural point of view, the card-making wasp is almost
superior to the bee, for the latter does not _build_ its house, it
only _furnishes_ it, as Latreille remarks with truth. The Brazilian
species of _Chartergus_, which the inhabitants call Lecheguana,[103]
manufactures a honey, the use of which is not without danger, as it
occasions vertigo and sharp pains in the stomach. The naturalist,
Auguste Saint-Hilaire, during his sojourn in Brazil, himself
experienced ill effects from eating it.
[103] Hence the scientific name, _Chartergus lecheguana_.--ED.
There are, moreover, solitary wasps, which make their cells in holes
which they scoop out in the ground, or in the stalks of certain
plants. In the adult state these live on honey; but their larvæ are
carnivorous, and the female is obliged to bring them living insects.
The commonest of these solitary wasps belong to the genus _Odynerus_.
This insect makes its nest in the stalk of a bramble or briar (Fig.
358) with a mortar which it prepares. The larva (Fig. 356) lines its
cell with a silky cocoon. It is the last egg laid which is hatched the
first; then come the others, in an inverse order from that in which
they were deposited. If it had been in the other order, the insects
could not have come out of the cells without destroying on their way
the less advanced pupa.
[Illustration: Fig. 355.--A species of Odynerus.]
[Illustration: Fig. 356.--Larva of the Odynerus.]
[Illustration: Fig. 357.--Pupa of the Odynerus.]
[Illustration: Fig. 358.--Nest of an Odynerus in the stem of a bramble.]