ONTHOPHAGI AND ONITICELLI
After the notabilities of the Dung-beetle tribe, if we omit the
Geotrupes, who belong to a different clan, there remains, within the
very limited radius of my observation, the Onthophagus rabble, of which
I could gather a dozen different species around my house. What will
these small fry teach us?
Even more zealous than their big companions, they are the first that
hasten to exploit the heap left by the passing Mule. They come in
crowds and stay a long time working under the spread table that gives
them shade and coolness. Turn over the heap with your foot. You will be
surprised at the swarming population whose presence no outward sign
betrayed. The largest are scarce the size of a pea, but some are much
smaller still; and these dwarfs are no less busy than the others, no
less eager to crumble into dust the filth which, in the interests of
the public health, must be cleared away with all speed.
For the more important work of life there is nothing like the humble
toilers for realizing vast strength, made up of their joint weaknesses.
Swollen by numbers, the next to nothing becomes an enormous total.
Hurrying in detachments at the first news of the event, assisted
moreover in their sanitary work by their partners, the Aphodii, who are
as weak as they, the tiny Onthophagi soon clear the ground of its dirt.
Not that their appetite is equal to the consumption of such plentiful
provisions. What food do these pigmies need? A mere atom. But for that
atom, selected from among the exudations, search must be made amid the
wisps of masticated fodder. Hence, an endless division and dissection
of the lump, reducing it to dust which the sun sterilizes and the wind
dispels. As soon as the work is done—and very well done—the troop of
scavengers goes in search of another refuse-yard. Except for the period
of intense cold, which puts a stop to all activity, they are never
idle.
And do not run away with the idea that this filthy task entails an
inelegant shape and a ragged dress. Our squalor is unknown to the
insect. In its world, a navvy dons a sumptuous jerkin; an undertaker
decks himself in a triple saffron sash; a wood-cutter works in a velvet
coat. In like manner, the Onthophagus has his special gorgeousness.
True, the costume is always severe: brown and black are the predominant
colours, now dull, now polished as ebony. That is the general
groundwork, but how chaste and elegant are the decorative details!
One (O. lemur) has wing-cases of a light chestnut colour, with a
semicircle of black dots; a second (O. nuchicornis) has similar
chestnut wing-cases covered with splashes of Indian ink not unlike the
square Hebrew characters; a third (O. Schreberi), who is a glossy black
like that of jet, decks himself with four vermilion cockades; a fourth
(O. furcatus) lights up the tip of his short wing-cases with a gleam
similar to that of dying embers; many (O. vacca, O. cænobita and
others) have corselets and heads bright with the metal sheen of
Florentine bronze.
The graver’s work completes the beauty of the dress. Dainty chasing in
parallel grooves, delicate embroidery, knotty chaplets are distributed
in profusion among nearly all of them. Yes, the little Onthophagi, with
their short bodies and their nimble activity, are really pretty to look
at.
And then how original are their frontal decorations! These peace-lovers
delight in the panoply of war, as though they, the inoffensive ones,
thirsted for battle. Many of them crown their heads with threatening
horns. Let us mention a couple of the horned ones whose story will
occupy us more particularly. I mean, first, the Bull Onthophagus (O.
taurus), clad in raven black. He wears a pair of long horns, gracefully
curved and branching to either side. No pedigree bull, in the Swiss
meadows, can match them for curve or elegance. The second is the Forked
Onthophagus (O. furcatus), who is much smaller. His equipment consists
of a fork with three vertical prongs.
There you have the two chief subjects of this brief Onthophagus
biography. The others are equally worthy of being chronicled. From
first to last, they would all supply us with interesting details, some
of them even with peculiarities unknown elsewhere; but we must draw the
line somewhere in this multitude, which is difficult to observe in the
aggregate. And there is this more serious circumstance, that my choice
has not been free: I have had to content myself with the few lucky
discoveries made as the result of chance encounters out of doors and
with the few successful experiments made in the vivarium.
Two species only, the two which I have named, have proved satisfactory
in both directions. Let us watch them at work. They will show us the
principal features of the manner of life led by the whole tribe, for
they occupy the two extremes of the scale of sizes, the Bull
Onthophagus being one of the largest and the Forked Onthophagus one of
the smallest.
We will speak first of the nest. Contrary to my expectation, the
Onthophagi are indifferent nest-builders. With them we find no spheres
rolled joyously in the sunshine, no ovoids manipulated laboriously in
an underground workshop. Their business, that of reducing filth to
dust, appears to give them so much to do that they have no time left
for work demanding prolonged patience. They confine themselves to what
is strictly necessary and most rapidly obtained.
A perpendicular well is dug, a couple of inches deep, cylindrical in
shape and varying in bore according to the size of the well-sinker. The
pit of the Forked Onthophagus has the diameter of a lead-pencil; that
of the Bull Onthophagus is twice the width. Right at the bottom are the
grub’s provisions, plastered against the walls in a tightly-packed
heap. The total lack of free space at the sides of the pile shows how
the provisioning is done. There is not a sign of a niche, of the least
corner that would leave the mother enough liberty of movement to knead
and mould her bun. The material therefore is simply pressed down at the
bottom of the cylindrical sheath, where it takes the shape of a full
thimble.
I dig up some nests of the Forked Onthophagus near the end of July. It
is a crude piece of work, which surprises you by its roughness when you
think of the neat little worker. Wisps of hay, sticking out anyhow,
increase the untidy look of things. The nature of the materials,
supplied this time by the Mule, are partly the cause of this ugly
appearance.
The length of these nests is fourteen millimetres, the width seven.
[43] The upper surface is slightly concave, proving that the pressure
has been exercised by the mother. The lower end is rounded like the
bottom of the well which serves as a mould. I take a needle and with
the point of it I pick the rustic structure to pieces. The mass of
foodstuff occupies the base, forming the lower two-thirds of the
thimble into a compact block; the cell containing the egg is at the
top, under a thin, concave lid.
There is nothing fresh about the work of the Bull Onthophagus, which,
save for being larger, differs in no way from that of the Forked
Onthophagus. I am unacquainted with the insect’s modus operandi. As
regards the inner secrets of nest-building, these dwarfs are as
reticent as their big colleagues. One alone satisfied my curiosity, or
nearly; and then it was not an Onthophagus but a kindred species, the
Yellow-footed Oniticellus (O. flavipes).
I capture her in the last week of July, under a heap which a Mule
employed in treading out the corn on the thrashing-floor dropped during
a rest from work. The thick blanket, transformed by a hot sun into an
incomparable incubator, shelters a host of Onthophagi. The Oniticellus
is by herself. Her quick retreat down a yawning well attracts my
attention. I dig to a depth of about two inches and extract the lady of
the house together with her work, the latter in a sadly damaged
condition. I can, however, distinguish a sort of bag.
I install the Oniticellus in a tumbler, on a layer of heaped earth, and
give her as her nest-building materials what the Sacred Beetles and the
Copres prefer, the Sheep’s plastic paste. Caught at the moment when she
was about to lay, goaded by the irresistible needs of her ovaries, the
mother lends herself very obligingly to my wishes. She lays four eggs
in three days. This rapidity, which would doubtless be even greater if
my curiosity had not disturbed her in her task, is explained by the
simplicity of the work.
The mother goes to the lower surface of the stuff which I have supplied
and detaches from the central and softest part a slice sufficient for
her plans, removing it all in one piece, by means of a circular
section. It is the same method as that employed by the Copris taking
from her loaf the wherewithal to make a pellet. There is a pit
immediately below, dug in advance. The Oniticellus goes down it with
her burden.
I wait half an hour, to give the work time to take shape, and then turn
the glass upside down, hoping to surprise the mother in her domestic
business. The original little lump is now a bag moulded by pressure
against the sides of the well. The mother is at the bottom, motionless,
bewildered by my disturbing visit and the intrusion of light. To see
her working with her forehead and legs in order to spread the matter,
crush it and apply it to its earthen sheath seems to me a very
difficult thing to do. I abandon the attempt and restore the glass to
its first position.
A little later, I make a second examination, when the mother has left
her burrow. The work is now finished. The outward form is that of a
thimble fifteen millimetres deep by ten wide. [44] The flat end has all
the appearance of a lid fitted to the opening and carefully soldered
on. The rounded lower half of the thimble is full. This is the grub’s
larder. Above is the hatching-chamber, with the egg sticking up from
the floor, fixed perpendicularly by one end.
Great is the danger for the Oniticellus and the Onthophagus, offspring
of the dog-days, both of them. Their jar of preserves is greatly
restricted in volume. Its shape is in no way calculated to reduce
evaporation; it is too near the surface of the soil to escape the
dangerous dryness of the air. If the cake should harden, the grub will
die, after its abstinence has been prolonged to the utmost limits of
endurance.
I place in glass tubes, which will represent the native well, a few
Onthophagus- and Oniticellus-thimbles, first contriving an opening in
the side which will enable me to see what happens within. I close the
tubes with a plug of cotton and keep them in a shady part of my study.
Evaporation must be very slight in these impermeable and moreover
plugged sheaths. Nevertheless it is enough to produce in a few days a
degree of dryness which is fatal to feeding.
I see the starvelings remain motionless, unable to bite into the
hateful crust; I see them lose their plumpness, I see them wrinkle and
shrivel, and at last, in a fortnight’s time, take on all the appearance
of death. I replace the dry cotton with wet cotton. The atmosphere in
the tubes becomes damp; the thimbles are gradually saturated with the
moisture, swell out and soften; and the dying come back to life. They
do so to such good purpose that the whole cycle of the metamorphoses is
safely accomplished, on condition that the wet cotton be renewed from
time to time.
My carefully graduated artificial shower, with its damped cotton to
represent the clouds, inspires that return to life. It is like a
resurrection. In the normal conditions prevailing in the torrid,
rain-grudging month of August, the probability of an equivalent of that
shower is almost nil. How then is the fatal drying-up of the victuals
avoided? To begin with, there are, so it seems to me, certain gifts
bestowed on these little ones so inadequately protected by their
mother’s industry against the enemy, drought. I have seen Onthophagus-
and Oniticellus-larvæ recover their appetite, their plumpness and their
vigour under the wet cotton, after a three weeks’ fast that had reduced
them to a wrinkled pilule. This faculty of endurance has its uses: it
enables the possessor to await, in a state of lethargy akin to death,
the few, very uncertain drops of rain that will put an end to the
famine. It comes to the grub’s rescue, but it is not sufficient: the
prosperity of a race cannot be based upon privation.
There is something more, therefore; and this is furnished by the
mother’s instinct. Whereas the manufacturers of pears and ovoids always
dig their burrow at an open spot, with no other protection than the
mound of earth flung up, the makers of little thimbles bore their well
directly under the material exploited and go by preference to the
voluminous droppings of the Horse and the Mule. Under this thick
mattress, the soil, protected against sun and wind, keeps fresh and
damp for some little time, steeped as it is in the moisture from the
dung.
For that matter, the danger does not last long. The egg yields up the
grub in less than a week; and the larva attains its full development
within a dozen days or so, if nothing untoward happens. This makes
about twenty days in all for the critical period of the Onthophagus and
the Oniticellus. What does it matter if the walls of the emptied
thimble do dry after that! The nymph will be all the better off in a
solid casket, which will easily crumble to bits later, when, with the
first September rains, the insect effects its release.
In appearance and habits the grub resembles that which the Sacred
Beetle and the others have introduced to us. It possesses the same
aptitude for defending the cell against the dangerous intrusion of the
dry air; the same zeal, the same nimbleness in cementing the least
breach with the putty of the intestines; the same knapsack hunching the
middle of the back.
The grub of the Oniticellus has the most remarkable hump of all. Would
you care to have a quick and yet a faithful sketch of it? Draw a short,
wrinkled sausage. About the middle of this sausage, on the side, graft
an appendix. There you have the beast, in three almost equal parts. The
lower portion is the abdomen; the upper, where you are at first
inclined to look for the head, so clearly does it appear to be a
continuation of the part below, is the hump, the inordinate,
extravagant hump, bigger than caricaturist ever dared conceive in the
wildest flights of his imagination. It occupies the place which by
rights belongs to the chest and head. Then where are these? Thrust
aside by the monstrous knapsack, they constitute a lateral appendage, a
mere knob. The strange creature bends at right angles under the weight
of its hump.
When nature goes in for the grotesque, she leaves us behind. Is
grotesque the right word? I have seen representations of Monkeys
adorned with preposterous noses which Rabelais, for all his inspired
vision of the huge, never conceived; and this though he invented the
nose ‘like the beak of a limbeck, in every part thereof most variously
diapered with the twinkling sparkles of crimson blisters budding forth,
and purpled with pimples all enamelled with thick-set wheals of a
sanguine colour, bordered with gules.’ [45] I know some who are all
scrubby with shock-headed wigs and whiskers and imperials in which
every hairy drollery seems to be epitomized; and yet there is not a
doubt that noses ‘like the beak of a limbeck’ and bristly faces are
highly admired in the simian clan. There is no boundary between the
fashionable and the grotesque. It all depends upon the appraiser.
If the grub with the outrageous hump were to show itself in public, it
would doubtless represent the supreme expression of the beautiful in
the eyes of the Oniticellus and the Onthophagus. Because it is a
recluse, nobody sees it. Its charms would remain unknown but for the
philosophical observer, who says to himself:
‘Everything is good that harmonizes with the functions to be fulfilled.
The grub requires a cement-bag to safeguard its provisions against
desiccation; it is born with a knapsack on its back so that it may
live.’
Thus is the hump excused and abundantly justified.
Its usefulness is displayed from another point of view. The thimble is
of such a niggardly size that the grub consumes it almost entirely. All
that remains is a thin layer, a crumbling remnant which would provide
no security for the nymph. The ruined dwelling has to be strengthened,
to be lined with a new wall. For this purpose, the larva of the
Oniticellus empties the whole of its knapsack and gives its cell a
complete coating of cement, after the manner of the Sacred Beetle and
others.
The grub of the different species of Onthophagi does more artistic
work. Placing its putty drop by drop, it constructs a mosaic of
lightly-projecting scales, suggesting those of a cedar-cone. When
finished, well dried and stripped of the last shreds of the original
thimble, the shell thus obtained by the Bull Onthophagus is the size of
an average filbert and resembles the pretty cone of the alder-tree. The
imitation is so good that I was taken in by it the first time that I
handled the curious product when digging in my cages. It needed the
contents of the mock alder-cone to show me my mistake. The hump has an
artfulness of its own: it was keeping this elegant specimen of
stercoral jewellery in reserve for us.
The nymph of the Onthophagi provides us with another surprise. My
observations are confined to two species only: the Bull Onthophagus and
the Forked Onthophagus; but the difference between the two, in size and
shape, is great enough to allow me to generalize and apply the
following singular fact to the whole genus.
About the middle of the fore-edge of the corselet the nymph is armed
with a very distinct horn, projecting for about one-twelfth of an inch.
The horn is transparent, colourless and limp, as are all the budding
organs at this period, particularly the legs, the cornicles of the
forehead and the mouth-parts. This crystalline protuberance proclaims a
future horn as clearly as the mandible is proclaimed by its initial
nipple or the wing-case by its sheath. Any insect-collector will
understand my amazement. A horn there, on the prothorax! But no
Onthophagus wears such a weapon as that! The register of my
insect-house duly records the genus of the insect, but I dare not
believe it.
The nymph moults. Together with the cast skin, the unfamiliar horn
dries up and falls off, leaving not the least trace behind it. My two
Onthophagi, recently disguised in strange armour, now have their
corselets bare.
This fleeting organ, which disappears without leaving even an
excrescence, this temporary horn at a spot destined in the end to be
unmailed, gives rise to a few reflections. The Dung-beetles, those
placid creatures, generally favour a warlike harness: they love
outlandish weapons, halberds, spears, grappling-irons, scimitars. Let
us hurriedly recall the horn of the Spanish Copris. No Rhinoceros in
the Indian jungles boasts one to compare with it upon his nose. Broad
at the base, pointed at the tip, curved like a bow, when the head is
lifted the horn bends back till it touches the keel of the obliquely
truncated corselet. It might be a harpoon intended for ripping up some
monster. Remember also the Minotaur, [46] who looks as though he were
going to spit his foe with his sheaf of three couched lances, and the
Lunary Copris, horned on the forehead, armed with a pike on each
shoulder and wearing a corselet notched with little crescents that
remind us of the short curved knife of the pork-butcher.
The Onthophagi have a most varied arsenal. One, O. taurus, wears the
Bull’s crescent-shaped horns; a second, O. vacca, prefers a wide, short
blade, with its point sheathed in a notch in the corselet; a third, O.
furcatus, wields a trident; yet another, O. nuchicornis, owns a dagger
with a winged handle; and again O. cænobita sports a cavalryman’s
sword. The worst-equipped crown their foreheads with a transversal
crest, with a pair of cornicles.
What is the good of this panoply? Are we to look upon it as a set of
tools, pickaxes, mattocks, pitchforks, spades, levers, which the insect
might ply in digging? By no means. The only industrial implements are
the forehead and the legs, especially the fore-legs. I have never
discovered a Dung-beetle of any sort making use of her weapons either
to excavate her burrow or to mix her provisions. Besides, as a rule,
the direction of the things alone would prevent their employment as
utensils. For a digging-job performed forwards, what would you have a
Spanish Copris do with her pickaxe, which points backwards? The
powerful horn does not face the obstacle attacked; it turns its back
upon it.
The Minotaur’s trident, though arranged in a suitable direction,
likewise remains unemployed. When deprived of this armour with a clip
of my scissors, the Beetle loses none of his mining-talents; he goes
underground quite as easily as his unmutilated fellow. And here is an
even more conclusive argument: the mothers, to whose lot the labour of
nest-building falls; the mothers, those conspicuous workers, are
deprived of these horny growths or possess them only on a greatly
reduced scale. They simplify the armour, or reject it entirely, because
it is more of an impediment than an assistance to their work.
Are we to look upon them as means of defence? Not that either. The
ruminants, the main feeders of the dung-eaters, are also given to
wearing frontal armour. The analogy of taste is obvious, though it is
impossible for us to suspect its remote reasons. The Ram, the Bull, the
Goat, the Chamois, the Stag, the Reindeer and the rest of them are
armed with horns and antlers which they use in amorous jousts or for
the protection of the threatened herd. The Onthophagi know nothing of
these contests. There is no strife among them; and, should danger
arise, they content themselves with shamming death by gathering their
legs under their abdomen.
Their armour then is a mere ornament, the fine feathers of masculine
coquetry. According to life’s law of competition, the best-dressed
carry off the palm. Though we may regard those rapiers on the nose as
queer, their wearers are of another opinion; and the most eccentric
enjoy the highest favour. The smallest extra pimple, springing up by
accident, is an added beauty which may decide the choice among the
suitors. The best-adorned captivate the mothers, perpetuate the breed
and hand down to their offspring the cornicle or the knob that caused
their triumph. Thus by degrees was the ornamentation at which the
entomologist wonders to-day formed and transmitted from generation to
generation, improving as it went.
To this dictum of the evolutionists the nymph of the Onthophagus
replies as follows:
‘I have on my back a budding horn, the germ of a bit of ornamentation
that can be very handsome, as witness the Bison Bubas, who turns it
into a splendid prow-shaped protuberance; witness also various exotic
relatives of mine, who lengthen their corselet into a magnificent spur.
I possess the wherewithal to bring about a revolution among my kin. If
I retained it, my bump, that charming innovation, would relegate my
rivals to the second rank; I should be preferred above all others; I
should become the founder of a family; and my descendants, completing
and improving on my first attempt, would behold the extinction of those
antiquated old things. Why should the lump on my back wither
purposeless? Why should my endeavour, repeated year after year for
centuries, never achieve the promised result?’
Listen to me, O ambitious one! The theorists, it is true, declare that
every casual acquisition, however trifling, is handed down and
increases if it be profitable; but don’t rely overmuch on that
assertion. I do not doubt the advantages which you might gain from a
little ornament. What I do very much doubt is the efficacity of time
and environment as an evolutionary factor. You will be well-advised to
believe that, born in the dim and distant past with a transient
callosity, you are continuing and will continue to be born with that
rudimentary excrescence without any chance of fixing it, hardening it
into a horn or obtaining an additional decoration for your
wedding-garment.
Be we men or Dung-beetles, we are all created in the image of an
unalterable prototype: the changing conditions of life alter us
slightly on the surface but never in the framework of our being. The
verdigris of the ages may encrust our medals, but it can give them
neither a new image nor a new superscription. Nothing will give me the
wings of a bird, desirable though these would be in the midst of our
human squalor; nor will anything bestow upon your adult age the
triumphal crest which your nymphal knob seemed to prognosticate.
The nymphs of both the Onthophagus and the Oniticellus attain their
maturity in some twenty days. During August the adult form appears with
the half-white, half-red costume which has become familiar to us from
our earlier studies. The normal colouring is fixed pretty quickly.
Nevertheless the insect is in no hurry to burst its shell: the
difficulty would be too great. It waits for the first showers of
September, which will come to its assistance by softening the casket.
The liberating rain arrives; and behold, issuing from the earth to rush
after food, the joyous small fry of the Onthophagi.
Among the domestic secrets which my cages reveal to me at this period,
one above all attracts my attention. I possess at the same time, in
separate establishments, the newcomers and the veterans, which last are
as brisk and eager in their pursuit of the victuals as are their sons,
now banqueting for the first time in the open. The cages are stocked
with two generations.
The same synchronizing of fathers and sons is observable among all the
Dung-beetles that build their nests in the spring: Sacred Beetles,
Copres and Geotrupes. The precaution which I have taken to watch the
hatchings and to place the youngsters in a special compartment as and
when they appeared confirms this remarkable simultaneity.
It is an entomological principle that the ancestor shall not see his
descendants; he dies once the future of his family is assured. By a
glorious privilege, the Sacred Beetle and his rivals are allowed to
know their successors: fathers and sons meet at the same banquet, not
in my cages, where the problems under consideration compel me to keep
them separate, but in the open fields. Together they gambol in the sun,
together they exploit the patch of dung encountered; and this life of
revelry lasts as long as autumn continues to supply fine days.
The cold weather arrives. Sacred Beetles and Copres, Onthophagi and
Gymnopleuri dig themselves a burrow, go down into it with provisions,
shut themselves in and wait. In January, on a frosty day, I dig into
the cages, which have no protection against the inclemencies of the
season. I go to work discreetly, so as not to submit all my captives to
the harsh test. Those whom I exhume each sit huddled in a shell, beside
the remaining provisions. All that the lethargy produced by the cold
allows them to do is to move their legs and antennæ a little when I
expose them to the sun.
Hardly has the imprudent almond-tree burst into blossom in February,
when some of the sleepers awake. Two of the earlier Onthophagi, O.
lemur and O. fronticornis, are very common at this time, already
crumbling the dung warmed by the sun on the high-road. Soon the
festival of spring begins; and all, large and small, newcomers and
veterans, hasten to take part in it. The old ones, not all, but at
least some of them, the best-preserved, fly off and get married a
second time, an unparalleled privilege. They have two families,
separated by an interval of a year. They can indeed have three, as is
evidenced by the Broad-necked Scarab, who, kept in a cage for three
years, gives me every year her collection of pears. Perhaps they even
go beyond this. The Dung-beetle tribe has its patriarchs who are truly
venerable.