THE LIFE OF THE
CATERPILLAR
BY
J. HENRI FABRE
TRANSLATED BY
Alexander Teixeira de Mattos
FELLOW OF THE ZOOLOGICAL SOCIETY OF LONDON
NEW YORK
DODD, MEAD AND COMPANY
1916
CONTENTS
PAGE
TRANSLATOR’S NOTE 5
CHAPTER
I THE PINE PROCESSIONARY: LAYING THE EGGS 9
II THE PINE PROCESSIONARY: THE NEST; THE COMMUNITY 27
III THE PINE PROCESSIONARY: THE PROCESSION 56
IV THE PINE PROCESSIONARY: METEOROLOGY 90
V THE PINE PROCESSIONARY: THE MOTH 111
VI THE PINE PROCESSIONARY: THE STINGING POWER 128
VII THE ARBUTUS CATERPILLAR 150
VIII AN INSECT VIRUS 161
IX THE PSYCHES: THE LAYING 186
X THE PSYCHES: THE CASES 217
XI THE GREAT PEACOCK 246
XII THE BANDED MONK 279
XIII THE SENSE OF SMELL 300
XIV THE CABBAGE-CATERPILLAR 331
TRANSLATOR’S NOTE
This, the sixth volume of the Collected Edition of Fabre’s
Entomological Works in English, is the first that I am preparing for
publication since the author’s death, on the 11th of October, 1915, at
an exceedingly advanced age. It contains all the essays, fourteen in
number, which he wrote on Butterflies and Moths, or their caterpillars.
Three of these, the chapters entitled The Great Peacock, The Banded
Monk and The Sense of Smell, are included under the titles of The Great
Peacock, The Oak Eggar and A Truffle-hunter: the Bolboceras Gallicus in
a volume of miscellaneous extracts from the Souvenirs entomologiques
translated by Mr. Bernard Miall and published by the Century Company.
The volume in question is named Social Life in the Insect World; and I
strongly recommend it to the reader, if only because of the excellent
photographs from nature with which it is illustrated.
Chapter III. of the present volume, The Pine Processionary: the
Procession, has appeared in the Fortnightly Review; and Chapter XIV.,
The Cabbage Caterpillar, the last essay but one from the author’s pen,
written, I believe, within two or three years of his death, was first
printed in the Century Magazine, some time before its publication in
the original. It does not form part of the Souvenirs entomologiques.
The remaining essays are new in their English guise.
Once more I wish to record my gratitude to Miss Frances Rodwell for the
faithful assistance which she has lent me in the preparation of this
volume, as in that of all the earlier volumes of the series.
Alexander Teixeira de Mattos.
Chelsea, 1916.
CHAPTER I
THE PINE PROCESSIONARY: THE EGGS AND THE HATCHING
This caterpillar has already had his story told by Réaumur, [1] but it
was a story marked by gaps. These were inevitable in the conditions
under which the great man worked, for he had to receive all his
materials by barge from the distant Bordeaux Landes. The transplanted
insect could not be expected to furnish its biographer with other than
fragmentary evidence, very weak in those biological details which form
the principal charm of entomology. To study the habits of insects one
must observe them long and closely on their native heath, so to speak,
in the place where their instincts have full and natural play.
With caterpillars foreign to the Paris climate and brought from the
other end of France, Réaumur therefore ran the risk of missing many
most interesting facts. This is what actually happened, just as it did
on a later occasion in the case of another alien, the Cicada. [2]
Nevertheless, the information which he was able to extract from a few
nests sent to him from the Landes is of the highest value.
Better served than he by circumstances, I will take up afresh the story
of the Processionary Caterpillar of the Pine. If the subject does not
come up to my hopes, it will certainly not be for lack of materials. In
my harmas [3] laboratory, now stocked with a few trees in addition to
its bushes, stand some vigorous fir-trees, the Aleppo pine and the
black Austrian pine, a substitute for that of the Landes. Every year
the caterpillar takes possession of them and spins his great purses in
their branches. In the interest of the leaves, which are horribly
ravaged, as though there had been a fire, I am obliged each winter to
make a strict survey and to extirpate the nests with a long forked
batten.
You voracious little creatures, if I let you have your way, I should
soon be robbed of the murmur of my once so leafy pines! Today I will
seek compensation for all the trouble I have taken. Let us make a
compact. You have a story to tell. Tell it me; and for a year, for two
years or longer, until I know more or less all about it, I shall leave
you undisturbed, even at the cost of lamentable suffering to the pines.
Having concluded the treaty and left the caterpillars in peace, I soon
have abundant material for my observations. In return for my indulgence
I get some thirty nests within a few steps of my door. If the
collection were not large enough, the pine-trees in the neighbourhood
would supply me with any necessary additions. But I have a preference
and a decided preference for the population of my own enclosure, whose
nocturnal habits are much easier to observe by lantern-light. With such
treasures daily before my eyes, at any time that I wish and under
natural conditions, I cannot fail to see the Processionary’s story
unfolded at full length. Let us try.
And first of all the egg, which Réaumur did not see. In the first
fortnight of August, let us inspect the lower branches of the pines, on
a level with our eyes. If we pay the least attention, we soon discover,
here and there, on the foliage, certain little whitish cylinders
spotting the dark green. These are the Bombyx’ eggs: each cylinder is
the cluster laid by one mother.
The pine-needles are grouped in twos. Each pair is wrapped at its base
in a cylindrical muff which measures about an inch long by a fifth or
sixth of an inch wide. This muff, which has a silky appearance and is
white slightly tinted with russet, is covered with scales that overlap
after the manner of the tiles on a roof; and yet their arrangement,
though fairly regular, is by no means geometrical. The general aspect
is more or less that of an immature walnut-catkin.
The scales are almost oval in form, semitransparent and white, with a
touch of brown at the base and of russet at the tip. They are free at
the lower end, which tapers slightly, but firmly fixed at the upper
end, which is wider and blunter. You cannot detach them either by
blowing on them or by rubbing them repeatedly with a hair-pencil. They
stand up, like a fleece stroked the wrong way, if the sheath is rubbed
gently upwards, and retain this bristling position indefinitely; they
resume their original arrangement when the friction is in the opposite
direction. At the same time, they are as soft as velvet to the touch.
Carefully laid one upon the other, they form a roof that protects the
eggs. It is impossible for a drop of rain or dew to penetrate under
this shelter of soft tiles.
The origin of this defensive covering is self-evident: the mother has
stripped a part of her body to protect her eggs. Like the Eider-duck,
she has made a warm overcoat for them out of her own down. Réaumur had
already suspected as much from a very curious peculiarity of the Moth.
Let me quote the passage:
“The females,” he says, “have a shiny patch on the upper part of
their body, near the hind-quarters. The shape and gloss of this
disk attracted my attention the first time that I saw it. I was
holding a pin, with which I touched it, to examine its structure.
The contact of the pin produced a little spectacle that surprised
me: I saw a cloud of tiny spangles at once detach themselves. These
spangles scattered in every direction: some seemed to be shot into
the air, others to the sides; but the greater part of the cloud
fell softly to the ground.
“Each of those bodies which I am calling spangles is an extremely
slender lamina, bearing some resemblance to the atoms of dust on
the Moths’ wings, but of course much bigger.... The disk that is so
noticeable on the hind-quarters of these Moths is therefore a
heap—and an enormous heap—of these scales.... The females seem to
use them to wrap their eggs in; but the Moths of the Pine
Caterpillar refused to lay while in my charge and consequently did
not enlighten me as to whether they use the scales to cover their
eggs or as to what they are doing with all those scales gathered
round their hinder part, which were not given them and placed in
that position to serve no purpose.”
You were right, my learned master: that dense and regular crop of
spangles did not grow on the Moth’s tail for nothing. Is there anything
that has no object? You did not think so; I do not think so either.
Everything has its reason for existing. Yes, you were well-inspired
when you foresaw that the cloud of scales which flew out under the
point of your pin must serve to protect the eggs.
I remove the scaly fleece with my pincers and, as I expected, the eggs
appear, looking like little white-enamel beads. Clustering closely
together, they make nine longitudinal rows. In one of these rows I
count thirty-five eggs. As the nine rows are very nearly alike, the
contents of the cylinder amount in all to about three hundred eggs, a
respectable family for one mother!
The eggs of one row or file alternate exactly with those in the two
adjoining files, so as to leave no empty spaces. They suggest a piece
of bead-work produced with exquisite dexterity by patient fingers. It
would be more correct still to compare them with a cob of Indian corn,
with its neat rows of seeds, but a greatly reduced cob, the tininess of
whose dimensions makes its mathematical precision all the more
remarkable. The grains of the Moth’s spike have a slight tendency to be
hexagonal, because of their mutual pressure; they are stuck close
together, so much so that they cannot be separated. If force is used,
the layer comes off the leaf in fragments, in small cakes always
consisting of several eggs apiece. The beads laid are therefore
fastened together by a glutinous varnish; and it is on this varnish
that the broad base of the defensive scales is fixed.
It would be interesting, if a favourable opportunity occurred, to see
how the mother achieves that beautifully regular arrangement of the
eggs and also how, as soon as she has laid one, all sticky with
varnish, she makes a roof for it with a few scales removed one by one
from her hind-quarters. For the moment, the very structure of the
finished work tells us the course of the procedure. It is evident that
the eggs are not laid in longitudinal files, but in circular rows, in
rings, which lie one above the other, alternating their grains. The
laying begins at the bottom, near the lower end of the double
pine-leaf; it finishes at the top. The first eggs in order of date are
those of the bottom ring; the last are those of the top ring. The
arrangement of the scales, all in a longitudinal direction and attached
by the end facing the top of the leaf, makes any other method of
progression inadmissible.
Let us consider in the light of reflection the elegant edifice now
before our eyes. Young or old, cultured or ignorant, we shall all, on
seeing the Bombyx’ pretty little spike, exclaim:
“How handsome!”
And what will strike us most will be not the beautiful enamel pearls,
but the way in which they are put together with such geometrical
regularity. Whence we can draw a great moral, to wit, that an exquisite
order governs the work of a creature without consciousness, one of the
humblest of the humble. A paltry Moth follows the harmonious laws of
order.
If Micromégas [4] took it into his head to leave Sirius once more and
visit our planet, would he find anything to admire among us? Voltaire
shows him to us using one of the diamonds of his necklace as a
magnifying-glass in order to obtain some sort of view of the
three-master which has run aground on his thumb-nail. He enters into
conversation with the crew. A nail-paring, curved like a horn,
encompasses the ship and serves as a speaking-trumpet; a tooth-pick,
which touches the vessel with its tapering end and the lips of the
giant, some thousand fathoms above, with the other, serves as a
telephone. The outcome of the famous dialogue is that, if we would form
a sound judgment of things and see them under fresh aspects, there is
nothing like changing one’s planet.
The probability then is that the Sirian would have had a rather poor
notion of our artistic beauties. To him our masterpieces of statuary,
even though sprung from the chisel of a Phidias, would be mere dolls of
marble or bronze, hardly more worthy of interest than the children’s
rubber dolls are to us; our landscape-paintings would be regarded as
dishes of spinach smelling unpleasantly of oil; our opera-scores would
be described as very expensive noises.
These things, belonging to the domain of the senses, possess a relative
æsthetic value, subordinated to the organism that judges them.
Certainly the Venus of Melos and the Apollo Belvedere are superb works;
but even so it takes a special eye to appreciate them. Micromégas, if
he saw them, would be full of pity for the leanness of human forms. To
him the beautiful calls for something other than our sorry, frog-like
anatomy.
Show him, on the other hand, that sort of abortive windmill by means of
which Pythagoras, echoing the wise men of Egypt, teaches us the
fundamental properties of the right-angled triangle. Should the good
giant, contrary to our expectation, happen not to know about it,
explain to him what the windmill means. Once the light has entered his
mind, he will find, just as we do, that there is beauty there, real
beauty, not certainly in that horrible hieroglyphic, the figure, but in
the unchangeable relation between the lengths of the three sides; he
will admire as much as we do geometry the eternal balancer of space.
There is, therefore, a severe beauty, belonging to the domain of
reason, the same in every world, the same under every sun, whether the
suns be single or many, white or red, blue or yellow. This universal
beauty is order. Everything is done by weight and measure, a great
statement whose truth breaks upon us all the more vividly as we probe
more deeply into the mystery of things.
Is this order, upon which the equilibrium of the universe is based, the
predestined result of a blind mechanism? Does it enter into the plans
of an Eternal Geometer, as Plato had it? Is it the ideal of a supreme
lover of beauty, which would explain everything?
Why all this regularity in the curve of the petals of a flower, why all
this elegance in the chasings on a Beetle’s wing-cases? Is that
infinite grace, even in the tiniest details, compatible with the
brutality of uncontrolled forces? One might as well attribute the
artist’s exquisite medallion to the steam-hammer which makes the slag
sweat in the melting.
These are very lofty thoughts concerning a miserable cylinder which
will bear a crop of caterpillars. It cannot be helped. The moment one
tries to dig out the least detail of things, up starts a why which
scientific investigation is unable to answer. The riddle of the world
has certainly its explanation otherwhere than in the little truths of
our laboratories. But let us leave Micromégas to philosophize and
return to the commonplaces of observation.
The Pine Bombyx has rivals in the art of gracefully grouping her
egg-beads. Among their number is the Neustrian Bombyx, whose
caterpillar is known by the name of “Livery,” because of his costume.
Her eggs are assembled in bracelets around little branches varying
greatly in nature, apple- and pear-branches chiefly. Any one seeing
this elegant work for the first time would be ready to attribute it to
the fingers of a skilled stringer of beads. My small son Paul opens
eyes wide with surprise and utters an astonished “Oh!” each time that
he comes upon the dear little bracelet. The beauty of order forces
itself upon his dawning attention.
Though not so long and marked above all by the absence of any wrapper,
the ring of the Neustrian Bombyx reminds one of the other’s cylinder,
stripped of its scaly covering. It would be easy to multiply these
instances of elegant grouping, contrived now in one way, now in
another, but always with consummate art. It would take up too much
time, however. Let us keep to the Pine Bombyx.
The hatching takes place in September, a little earlier in one case, a
little later in another. So that I may easily watch the new-born
caterpillars in their first labours, I have placed a few egg-laden
branches in the window of my study. They are standing in a glass of
water which will keep them properly fresh for some time.
The little caterpillars leave the egg in the morning, at about eight
o’clock. If I just lift the scales of the cylinder in process of
hatching, I see black heads appear, which nibble and burst and push
back the torn ceilings. The tiny creatures emerge slowly, some here and
some there, all over the surface.
After the hatching, the scaly cylinder is as regular and as fresh in
appearance as if it were still inhabited. We do not perceive that it is
deserted until we raise the spangles. The eggs, still arranged in
regular rows, are now so many yawning goblets of a slightly translucent
white; they lack the cap-shaped lid, which has been rent and destroyed
by the new-born grubs.
The puny creatures measure a millimetre [5] at most in length. Devoid
as yet of the bright red that will soon be their adornment, they are
pale-yellow, bristling with hairs, some shortish and black, others
rather longer and white. The head, of a glossy black, is big in
proportion. Its diameter is twice that of the body. This exaggerated
size of the head implies a corresponding strength of jaw, capable of
attacking tough food from the start. A huge head, stoutly clad in horn,
is the predominant feature of the budding caterpillar.
These macrocephalous ones are, as we see, well-armed against the
hardness of the pine-needles, so well-armed in fact that the meal
begins almost immediately. After roaming for a few moments at random
among the scales of the common cradle, most of the young caterpillars
make for the double leaf that served as an axis for the native cylinder
and spread themselves over it at length. Others go to the adjacent
leaves. Here as well as there they fall to; and the gnawed leaf is
hollowed into faint and very narrow grooves, bounded by the veins,
which are left intact.
From time to time, three or four who have eaten their fill fall into
line and walk in step, but soon separate, each going his own way. This
is practice for the coming processions. If I disturb them ever so
little, they sway the front half of their bodies and wag their heads
with a jerky movement similar to the action of an intermittent spring.
But the sun reaches the corner of the window where the careful rearing
is in progress. Then, sufficiently refreshed, the little family
retreats to its native soil, the base of the double leaf, gathers into
an irregular group and begins to spin. Its work is a gauze globule of
extreme delicacy, supported on some of the neighbouring leaves. Under
this tent, a very wide-meshed net, a siesta is taken during the hottest
and brightest part of the day. In the afternoon, when the sun has gone
from the window, the flock leaves its shelter, disperses around,
sometimes forming a little procession within a radius of an inch, and
starts browsing again.
Thus the very moment of hatching proclaims talents which age will
develop without adding to their number. In less than an hour from the
bursting of the egg, the caterpillar is both a processionary and a
spinner. He also flees the light when taking refreshment. We shall soon
find him visiting his grazing-grounds only at night.
The spinner is very feeble, but so active that in twenty-four hours the
silken globe attains the bulk of a hazel-nut and in a couple of weeks
that of an apple. Nevertheless, it is not the nucleus of the great
establishment in which the winter is to be spent. It is a provisional
shelter, very light and inexpensive in materials. The mildness of the
season makes anything else unnecessary. The young caterpillars freely
gnaw the logs, the poles between which the threads are stretched, that
is to say, the leaves contained within the silken tent. Their house
supplies them at the same time with board and lodging. This excellent
arrangement saves them from having to go out, a dangerous proceeding at
their age. For these puny ones, the hammock is also the larder.
Nibbled down to their veins, the supporting leaves wither and easily
come unfastened from the branches; and the silken globe becomes a hovel
that crumbles with the first gust of wind. The family then moves on and
goes elsewhere to erect a new tent, lasting no longer than the first.
Even so does the Arab move on, as the pastures around his camel-hide
dwelling become exhausted. These temporary establishments are renewed
several times over, always at greater heights than the last, so much so
that the tribe, which was hatched on the lower branches trailing on the
ground, gradually reaches the higher boughs and sometimes the very
summit of the pine-tree.
In a few weeks’ time, a first moult replaces the humble fleece of the
start, which is pale-coloured, shaggy and ugly, by another which lacks
neither richness nor elegance. On the dorsal surface, the various
segments, excepting the first three, are adorned with a mosaic of six
little bare patches, of a bright red, which stand out a little above
the dark background of the skin. Two, the largest, are in front, two
behind and one, almost dot-shaped, on either side of the quadrilateral.
The whole is surrounded by a palisade of scarlet bristles, divergent
and lying almost flat. The other hairs, those of the belly and sides,
are longer and whitish.
In the centre of this crimson marquetry stand two clusters of very
short bristles, gathered into flattened tufts which gleam in the sun
like specks of gold. The length of the caterpillar is now about two
centimetres [6] and his width three or four millimetres. [7] Such is
the costume of middle age, which, like the earlier one, was unknown to
Réaumur.