THE PINE COCKCHAFER
In writing Pine Cockchafer at the head of this chapter, I am guilty of
a deliberate heresy: the insect’s orthodox name is Fuller Cockchafer
(Melolontha fullo, Lin.). We must not be fastidious, I know, in matters
of nomenclature. Make a noise of some sort, give it a Latin termination
and you will have, as far as euphony goes, the equivalent of many of
the labels pasted in the entomologist’s specimen-boxes. The cacophony
would be excusable if the barbarous expression signified nothing else
than the creature intended; but, generally speaking, this name
possesses, hidden among its Greek or other roots, a certain meaning in
which the novice hopes to find a little information.
He will be woefully disappointed. The scientific term refers to
subtleties difficult to grasp and of very slight importance. Too often
it leads him astray, suggesting views which have naught in common with
the truth as we know it from observation. Sometimes the errors are
flagrant; sometimes the allusions are grotesque and imbecile. Provided
that they have a decent sound, how greatly preferable are locutions in
which entomology finds nothing to dissect!
Fullo would be one of these, if the word had not a first sense which at
once occurs to the mind. This Latin expression means a “fuller,” one
who “fulls” cloth under running water, dressing it and ridding it of
the stiffness of the weaving. What connection has the Cockchafer who
forms the subject of this chapter with the working fuller? You may rack
your brains in vain: no acceptable answer will come.
The term fullo, applied to an insect, occurs in Pliny. In one chapter
the great naturalist treats of remedies for jaundice, fevers and
dropsy. A little of everything plays its part in this pharmacopœia: a
black Dog’s longest tooth; a Mouse’s nose wrapped in a pink rag; a
green Lizard’s right eye torn from the living reptile and placed in a
kid-skin bag; a Snake’s heart, torn out with the left hand; the four
joints of a Scorpion’s tail, including the sting, wrapped up in a black
cloth, provided that for three days the patient can see neither the
remedy nor him that applied it; and many other extravagances. We close
the book, alarmed by the slough of absurdities whence the art of
healing has come down to us.
In this medley of inanities, the forerunner of medicine, the fuller
makes his appearance. The text says:
“Tertium qui vocatur fullo, albis guttis,
dissectum utrique lacerto adalligant.”
To treat fevers, we must divide the Fuller Beetle into two parts and
fasten one half to the right arm and the other half to the left.
Now what did the ancient naturalist mean by this term Fuller Beetle? We
do not know exactly. The description albis guttis, white spots, would
fit the white-flecked Pinechafer pretty well, but it is not enough to
make us certain. Pliny himself seems to have been none too sure of his
wonderful cure. In his time, men’s eyes had not yet learnt how to look
at the insect. The creatures were too small; they were fit amusement
for children, who would tie them to the end of a long thread and make
them run round in a circle, but they were unworthy the attention of a
self-respecting man.
Pliny apparently got the word from the country-folk, always poor
observers and inclined to bestow extravagant names. The scholar
accepted the rustic locution, the work perhaps of a childish
imagination, and applied it as a makeshift, without further enquiries.
The word has come down to us a fragment of antiquity; our modern
naturalists have adopted it; and this is how one of our handsomest
insects became the Fuller. The majesty of the centuries has consecrated
the strange appellation.
In spite of all my respect for ancient languages, the term Fuller does
not appeal to me because in the circumstances it is nonsensical. Common
sense should take precedence of the aberrations of nomenclature. Why
not say Pine Cockchafer, in memory of the beloved tree, the paradise of
the insect during the two or three weeks of its aërial life? It would
be very simple; nothing could be more natural: a very good reason for
putting it last of all.
We have to wander a long time in the night of absurdity before reaching
the radiant light of truth. All our sciences bear witness to this, even
the science of number. Try to add a column of figures written in Roman
numerals: you will abandon the task, stupefied by the confusion of the
symbols, and you will realize how great a revolution was made in
arithmetic by the invention of the figure nought. Like the egg of
Columbus, it was indeed a very small thing, but it had to be thought
of.
Until the future casts the unfortunate Fuller into oblivion, we will
say Pine Cockchafer, so far as we are concerned. Using this name, no
one can make a mistake: our insect frequents the pine-tree only. It has
a handsome and portly appearance, vying with that of Oryctes
nasicornis. [52] Its costume, though not boasting the metallic
splendour dear to the Carabus, [53] the Buprestis, [54] and the
Cetonia, is at least unusually elegant. A black or brown ground is
thickly strewn with capricious spots of white velvet. It is at the same
time modest and magnificent.
By way of plumes, the male wears at the end of his short antennæ seven
large superposed leaves, which, opening and closing like a fan, betray
the emotions of the moment. At first sight one would take this superb
foliage for a sense-organ of great perfection, capable of perceiving
subtle odours, almost inaudible waves of sound or other means of
information unknown to our senses; but the female warns us not to go
too far in this direction. Her maternal duties demand that she should
possess a susceptibility to impressions at least as great as that of
the other sex; and yet her antennary plumes are very small and consist
of six niggardly leaves.
Then what is the use of the male’s enormous fan? The seven-leaved
apparatus is to the Pine-chafer what his long, quivering horns are to
the Capricorn and the panoply of the forehead to the Onthophagus and
the forked antlers of the mandibles to the Stag-beetle. Each decks
himself in his own fashion with nuptial extravagances.
The handsome Cockchafer appears at the summer solstice, almost
simultaneously with the first Cicadæ. [55] His punctual advent gives
him a place in the entomological calendar, which is no less regular
than that of the seasons. When the longest days come, those days which
seem endless and gild the harvest, he never fails to hurry to his tree.
The Midsummer bonfires, reminiscent of the festivals of the sun, which
the children kindle in the village streets, are no more punctual in
date. At this season, every evening, in the gloaming, if the weather be
still, the Cockchafer comes to visit the pine-trees in the enclosure. I
follow his evolutions with my eyes. With a silent, impetuous flight,
the males especially veer to and fro, displaying their great antennary
plumes; they make for the branches where the females await them; they
fly back and forth, visible as dark streaks against the pallor of the
sky, from which the last remnants of daylight are fading. They settle,
take flight again and resume their busy rounds. What do they do up
there, evening after evening, during the fortnight of the festival?
The thing is evident: they are wooing the ladies and they continue to
pay their respects until night has fallen. Next morning, both males and
females commonly occupy the lower branches. They lie singly motionless,
indifferent to passing events. They do not avoid the hand put out to
seize them. Hanging by their hind-legs, most of them nibbling a
pine-needle, they slumber drowsily, with the morsel, in their mouths.
When twilight returns, they resume their frolics.
To watch these frolics in the tops of the trees is hardly possible; let
us try to watch them in captivity. I collect four couples in the
morning and place them in a roomy cage, with a few twigs of pine. The
spectacle hardly comes up to my expectations. This is because they are
deprived of the power of flight. At most, from time to time, a male
approaches his coveted bride; he spreads the leaves of his antennæ and
shakes them with a slight quiver, perhaps to discover if he is welcome;
he shows off, exhibiting his antlered beauty. It is a useless display:
the female does not budge, as though insensible to these
demonstrations. Captivity has sorrows that are hard to overcome. More
than this I could not see. Pairing, it seems, must take place during
the later hours of the night, so that I have missed the propitious
moment.
One detail in particular interested me. The Pine-chafer possesses a
musical instrument. Male and female are similarly gifted. Does the
suitor make use of his faculty as a means of seduction and appeal? Does
the other answer her lover’s strophe with a similar strophe? That this
happens under normal conditions, amidst the branches, is highly
probable; but I should not care to say so for certain, having never
heard anything of the kind among the pine-trees or in the cage.
The sound is produced by the tip of the abdomen, which, with a gentle
movement, alternately rises and falls, rubbing its rear-most segments
against the hinder edge of the wing-cases, which are held motionless.
There is no special appliance on the rubbing surface nor on the surface
rubbed. The magnifying-glass searches in vain for minute ridges such as
might produce a note. On either hand all is smooth. How then is the
sound produced?
Moisten the tip of a finger and run it over a strip of glass, over a
window-pane: you will obtain a fairly well-sustained sound, not unlike
that emitted by the Cockchafer. Better still: use a bit of india-rubber
to rub the glass with and you will obtain a pretty faithful
reproduction of the noise made by the insect. If the musical rhythm is
well preserved, the imitation might deceive anybody.
Well, in the Cockchafer’s apparatus, the pad of the finger-tip and the
bit of india-rubber are represented by the softness of the moving
abdomen and the window-pane by the plate of the wing-cases, a thin,
rigid plate eminently capable of vibration. The Cockchafer’s musical
instrument is thus one of the simplest.
A small number of other Beetles are endowed with the same privilege.
These include the Spanish Copris and the truffle-eating Bolboceras.
[56] Both make a sound by means of slight oscillations of the abdomen,
which gently grazes the hinder edge of the wing-cases.
The Cerambyx-beetles have another method, likewise based on friction.
The Great Capricorn, for instance, moves his corselet over its junction
with the thorax. There is here a large cylindrical projection which
fits tightly into the cavity of the corselet and forms a joint which is
at the same time powerful and mobile. This projection is surmounted by
a convex surface, shaped like an heraldic scutcheon, perfectly smooth
and absolutely devoid of any sort of fluting. This is the musical-box.
The edge of the corselet, itself smooth inside, rubs over this surface,
passing to and fro with a rhythmical movement and thus creating a sound
which is once more like that of a window-pane rubbed with a moistened
finger. Still, I am unable to make the dead insect’s apparatus sound by
moving the corselet myself. Though I hear nothing, I at least feel with
my moving fingers the shrill vibration of the surfaces rubbed. A little
more and the sound would be audible. What is lacking? The stroke of the
bow which the live insect alone is able to supply.
We find the same mechanism in the small Capricorn, Cerambyx cerdo, [57]
and in the denizen of the willows, the Rose-scented Aromia, A.
moschata. [58] On the other hand, the Ægosoma and Ergates, mighty
Longicorns both, are without the projection fitting into the corselet,
or rather possess of it only as much as is strictly necessary to join
the two parts together. Consequently the two big night-insects are
dumb.
Though we are acquainted with the simple mechanism of the Cockchafer’s
instrument, its employment none the less remains a riddle. Does the
insect use it as a means of nuptial appeal? This is likely.
Nevertheless, I have not heard the slightest grating on the pines, in
spite of all my attention at propitious hours. I have heard nothing
either in the cages, where distance formed no obstacle to the hearing.
If we would make the Cockchafer squeak, all that we need do is to take
him in our fingers and tease him a little. The sound box works at once
and does not cease until we do. What we now hear is not a song but a
complaint, a protest against misfortune. It is a singular world in
which sorrow is translated by couplets and joy by silence.
The other scrapers of the abdomen or corselet behave in like fashion.
When surprised upon her pills, at the bottom of her burrow, the mother
Copris groans, for a moment bewailing her fate: the Bolboceras, held
captive in the hand, protests with a gentle elegy; the Capricorn when
caught sets up a desperate grating. All are mute as soon as the danger
is past; all likewise persist in their silence when absolutely at rest.
I never knew any of the three to sound his instrument apart from the
alarm to which I subjected them.
Others, supplied with highly improved instruments, sing to beguile
their solitude, to summon each other to the wedding, to celebrate the
joys of life and the festival of the sunshine. Most of these singers
are mute in a moment of danger. At the least disturbance, the Decticus
[59] shuts up his musical box and veils his dulcimer, on whose notes he
was playing with his bow; the Cricket [60] furls the wings which were
vibrating above his back.
On the other hand, the Cicada raises a desperate outcry in our fingers;
and the Ephippiges [61] bemoans his fate in a minor key. Sorrows and
joys are translated into the same tongue, so that it becomes difficult
to say for what exact purpose the stridulating organ is intended. When
left in peace, does the insect actually celebrate its happiness? When
teased, does it bewail its misfortune? Does it try to overawe its
enemies with noise? Could the sound-apparatus, at the requisite moment
be a means of defence or intimidation? If the Capricorn and the Cicada
made a sound when in danger, then why are the Decticus and the Cricket
silent?
After all, we know next to nothing of the determining causes of insect
phonetics. We know very little more of the sounds perceived. Do the
insect’s ears catch the same sounds as ours do? Is it sensible, in
particular, to what we call musical sounds? Without, I may say, any
hope of solving this obscure problem, I tried an experiment which is
worth relating. One of my readers, filled with enthusiasm for what my
animals taught him, sent me a musical box from Geneva, hoping that it
might be useful to me in my acoustic researches. And it really was so.
Let me tell the story. It will give me the opportunity of thanking the
kind sender of the present.
The little musical-box has a fairly varied selection of pieces, all
translated into notes of crystal clearness which should, to my
thinking, attract the attention of an insect audience. One of the tunes
best suited to my plans is that from Les Cloches de Corneville. With
this lure shall I secure the attention of a Cockchafer, a Capricorn or
a Cricket?
I begin with a Capricorn, the little Cerambyx cerdo. I seize the moment
when he is courting his mate at a distance. With his delicate antennæ
extended motionless, he seems to be making enquiries. Now, melodiously,
Les Cloches de Corneville ring out: ding-dong-ding-dong. The insect’s
meditative posture is unchanged. There is not the least tremor, not the
least inflexion of the antennæ, the organs of hearing. I renew the
attempt, altering the hour and the degree of daylight. My experiments
are useless: there is not a movement of the antennæ to denote that the
insect pays the least attention to my music.
The same result, with the Pine-chafer, whose antennary leaves retain
exactly the same position as when all was silent; the same result with
the Cricket, whose tiny, out-stretched, thread-like antennæ should
vibrate easily under the impact of the sound-waves. My three subjects
are absolutely indifferent to my methods of exciting emotion: not one
of them gives a hint of feeling any impression whatever.
Years ago, a mortar thundering under the plane-tree in which the
orchestra of the Cicadæ [62] was performing did not for a moment
interrupt or otherwise affect their concert: at a later date, the
hullabaloo of a holiday crowd and the crackling of fireworks let off
close by failed to disturb the geometry of a Garden Spider working at
her web, [63] to-day, the limpid tinkle of Les Cloches de Corneville
leaves the insect profoundly indifferent, in so far as we are able to
judge. Are we to infer deafness? That would be going a great deal too
far.
These experiments merely justify our opinion that the insect’s
acoustics are not ours, even as the optics of its faceted eyes are not
to be compared with those of our own. A mechanical toy, the microphone,
hears—if I be permitted to say so—that which to us is silence; it would
not hear a mighty uproar; it would be thrown out of gear and work
imperfectly if subjected to the din of thunder. What of the insect,
another, even more delicate toy! It knows nothing of our sounds,
whether musical notes or noises. It has those of its own little world,
apart from which other sound-waves possess no value.
In the first fortnight of July, the male Pine-chafers observed in the
vivarium withdraw to one side, sometimes bury themselves and die quite
peacefully, killed by age. The mothers, on the other hand, busy
themselves with laying their eggs, or, more accurately, with sowing
them. They poke the soil with the tip of their abdomen, shaped like a
blunt ploughshare, sinking into it sometimes altogether, sometimes to
their shoulders. The eggs, to the number of a score, are laid
separately, one by one, in little round cavities the size of a pea.
They receive no further attention. They are positively dibbled into the
ground.
This method recalls the arachis, the African [64] Leguminosa, which
curls its floral peduncles and thrusts its oleaginous seeds with their
nutty flavour, underground to germinate. It reminds us too of a plant
of my own country-side, the subterranean or double-fruited vetch (Vicia
amphicarpos, Dorth.), which produces two sorts of pods, the first above
ground, containing numerous seeds, the second under the surface,
containing large seeds, usually no more than two in number. For that
matter the two kinds are equal in value and give a similar yield.
Let the soil be moistened and everything is ready for the germination;
the preliminary sowing has been done by the vetch and the arachis
themselves. Here the plant vies with the animal in maternal cares: the
Pine-chafer does no more than the two Leguminosæ. She sows in the
ground and that is all, absolutely all. How far removed we are from the
Minotaur, so careful of her family!
The eggs, ovoids blunted at either end, measure four to five
millimetres [65] in length. They are a dull white, firm to the touch,
as though supplied with a chalky shell copied from that of a Hen’s egg.
This appearance is deceptive: what remains after the hatching is a
delicate, flexible, translucent membrane. The chalky look is due to the
contents, which show through. The hatching takes place in the middle of
August, a month after the laying.
How shall I feed the grubs and watch them take their first mouthfuls? I
go by what I have learnt from the spots frequented by the grown larvæ.
I make a mixture of moist sand and the fine detritus of any leaves
whatever browned with decay. The new-born grubs thrive in this
environment: I see them opening short galleries here and there, seizing
on decayed particles and devouring them with every sign of
satisfaction, so much so that, if I had the leisure to continue this
rearing for the three or four years required, I should certainly obtain
larvæ ripe for transformation.
But there is no need to waste my time in rearing them thus: by digging
in the fields I obtain the fully developed grub. It is magnificently
fat, bent into a hook, a creamy white in front and an earthy brown
behind, because of the wallet in which it hoards the stercoral treasure
destined later to plaster and cement the cell in which the nymphosis
will take place. All these hook-shaped wallet-bearers, Oryctes- and
Cetonia-larvæ, Cockchafer- and Anoxia-grubs, are hoarders of fæcal
matter: they reserve in their brown paunches the wherewithal to build
themselves a lodging when the time comes.
I collect my fat grubs in a sandy soil, where lean grass-tufts grow, at
a great distance from any resinous tree except the cypress, which the
adult insect does not visit. The Cockchafer, therefore, after her
regulation frolics on the pines, came to this place from afar to lay
her eggs. She feeds frugally on pine-needles; her larva calls for the
remnants of any leaves softened by underground putrefaction. This is
why the nuptial paradise is deserted.
The larva of the Common Cockchafer, the White Worm, a voracious nibbler
of tender roots, is the scourge of our crops; that of the Pine
Cockchafer seems to me to work hardly any havoc. Decayed rootlets,
decomposing vegetable remains, are all that it needs. As to the adults,
they browse upon the green pine-needles, without abusing their
privilege. If I were a land-owner, I should not trouble my head about
their devastations. A few mouthfuls taken from the immense store of
leaves, a few pine-needles robbed of their points, are not a serious
matter. Let us leave the Pine Cockchafer alone. He is an ornament of
the balmy twilight, a pretty jewel of the summer solstice.