AN INVADER - THE HARICOT - WEEVIL
If there is one vegetable on earth that more than any other is a gift of
the gods, it is the haricot bean. It has all the virtues: it forms a
soft paste upon the tongue; it is extremely palatable, abundant,
inexpensive, and highly nutritious. It is a vegetable meat which,
without being bloody and repulsive, is the equivalent of the horrors
outspread upon the butcher's slab. To recall its services the more
the Provencal idiom calls it the _gounflo-gus_--the filler
of the poor.
Blessed Bean, consoler of the wretched, right well indeed do you fill
the labourer, the honest, skilful worker who has drawn a low number in
the crazy lottery of life. Kindly Haricot, with three drops of oil and a
dash of vinegar you were the favourite dish of my young years; and even
now, in the evening of my days, you are welcome to my humble porringer.
We shall be friends to the last.
To-day it is not my intention to sing your merits; I wish simply to ask
you a question, being curious: What is the country of your origin? Did
you come from Central Asia with the broad bean and the pea? Did you make
part of that collection of seeds which the first pioneers of culture
brought us from their gardens? Were you known to antiquity?
Here the insect, an impartial and well-informed witness, answers: "No;
in our country antiquity was not acquainted with the haricot. The
precious vegetable came hither by the same road as the broad bean. It is
a foreigner, and of comparatively recent introduction into Europe."
The reply of the insect merits serious examination, supported as it is
by extremely plausible arguments. Here are the facts. For years
attentive to matters agricultural, I had never seen haricots attacked by
any insect whatever; not even by the Bruchidae, the licensed robbers of
On this point I have questioned my peasant neighbours. They are men of
the extremest vigilance in all that concerns their crops. To steal their
property is an abominable crime, swiftly discovered. Moreover, the
housewife, who individually examines all beans intended for the
saucepan, would inevitably find the malefactor.
All those I have spoken to replied to my questions with a smile in which
I read their lack of faith in my knowledge of insects. "Sir," they said,
"you must know that there are never grubs in the haricot bean. It is a
blessed vegetable, respected by the weevil. The pea, the broad bean, the
vetch, and the chick-pea all have their vermin; but the haricot, _lou
gounflo-gus_, never. What should we do, poor folk as we are, if the
_Courcoussoun_ robbed us of it?"
The fact is that the weevil despises the haricot; a very curious dislike
if we consider how industriously the other vegetables of the same family
are attacked. All, even the beggarly lentil, are eagerly exploited;
whilst the haricot, so tempting both as to size and flavour, remains
untouched. It is incomprehensible. Why should the Bruchus, which without
hesitation passes from the excellent to the indifferent, and from the
indifferent to the excellent, disdain this particularly toothsome seed?
It leaves the forest vetch for the pea, and the pea for the broad bean,
as pleased with the small as with the large, yet the temptations of the
haricot bean leave it indifferent. Why?
Apparently because the haricot is unknown to it. The other leguminous
plants, whether native or of Oriental origin, have been familiar to it
for centuries; it has tested their virtues year by year, and, confiding
in the lessons of the past, it bases its forethought for the future upon
ancient custom. The haricot is avoided as a newcomer, whose merits it
has not yet learned.
The insect emphatically informs us that with us the haricot is of recent
date. It has come to us from a distant country: and assuredly from the
New World. Every edible vegetable attracts its consumers. If it had
originated in the Old World the haricot would have had its licensed
consumers, as have the pea, the lentil, and the broad bean. The smallest
leguminous seed, if barely bigger than a pin's head, nourishes its
weevil; a dwarf which patiently nibbles it and excavates a dwelling; but
the plump, delicious haricot is spared.
This astonishing immunity can have only one explanation: like the potato
and the maize-plant, the haricot is a gift of the New World. It arrived
in Europe without the company of the insect which exploits it in its
native country; it has found in our fields another world of insects,
which have despised it because they did not know it. Similarly the
potato and the ear of maize are untouched in France unless their
American consumers are accidentally imported with them.
The verdict of the insect is confirmed by the negative testimony of the
ancient classics; the haricot never appears on the table of the Greek or
Roman peasant. In the second Eclogue of Virgil Thestylis prepares the
repast of the harvesters:--
Thestylis et rapido fessis messoribus aestu
Allia serpyllumque herbas contundit olentes.
This mixture is the equivalent of the _aioli_, dear to the Provencal
palate. It sounds very well in verse, but is not very substantial. On
such an occasion men would look for that fundamental dish, the plate of
red haricots, seasoned with chopped onions. All in good time; this at
least would ballast the stomach. Thus refreshed in the open air,
listening to the song of the cigales, the gang of harvesters would take
their mid-day rest and gently digest their meal in the shadows of the
sheaves. Our modern Thestylis, differing little from her classic sister,
would take good care not to forget the _gounflo-gus_, that economical
resource of large appetites. The Thestylis of the past did not think of
providing it because she did not know it.
The same author shows us Tityrus offering a night's hospitality to his
friend Meliboeus, who has been driven from his property by the
soldiers of Octavius, and goes limping behind his flock of goats. We
shall have, says Tityrus, chestnuts, cheese, and fruits. History does
not say if Meliboeus allowed himself to be tempted. It is a pity; for
during the frugal meal we might have learned in a more explicit fashion
that the shepherds of the ancient world were not acquainted with the
Ovid tells us, in a delightful passage, of the manner in which Philemon
and Baucis received the gods unawares as guests in their humble cottage.
On the three-legged table, which was levelled by means of a potsherd
under one of the legs, they served cabbage soup, rusty bacon, eggs
poached for a minute in the hot cinders, cornel-berries pickled in
brine, honey, and fruits. In this rustic abundance one dish was lacking;
an essential dish, which the Baucis of our countryside would never
forget. After bacon soup would follow the obligatory plate of haricots.
Why did Ovid, so prodigal of detail, neglect to mention a dish so
appropriate to the occasion? The reply is the same as before: because he
did not know of it.
In vain have I recapitulated all that my reading has taught me
concerning the rustic dietary of ancient times; I can recollect no
mention of the haricot. The worker in the vineyard and the harvester
have their lupins, broad beans, peas, and lentils, but never the bean of
beans, the haricot.
The haricot has a reputation of another kind. It is a source of
flatulence; you eat it, as the saying is, and then you take a walk. It
lends itself to the gross pleasantries loved of the populace; especially
when they are formulated by the shameless genius of an Aristophanes or a
Plautus. What merriment over a simple allusion to the sonorous bean,
what guffaws from the throats of Athenian sailors or Roman porters! Did
the two masters, in the unfettered gaiety of a language less reserved
than our own, ever mention the virtues of the haricot? No; they are
absolutely silent concerning the trumpet-voiced vegetable.
The name of the bean is a matter for reflection. It is of an unfamiliar
sound, having no affinity with our language. By its unlikeness to our
native combinations of sounds, it makes one think of the West Indies or
South America, as do _caoutchouc_ and _cacao_. Does the word as a matter
of fact come from the American Indians? Did we receive, together with
the vegetable, the name by which it is known in its native country?
Perhaps; but how are we to know? Haricot, fantastic haricot, you set us
a curious philological problem.
It is also known in French as _faseole_, or _flageolet_. The Provencal
calls it _faiou_ and _faviou_; the Catalan, _fayol_; the Spaniard,
_faseolo_; the Portuguese, _feyao_; the Italian, _fagiuolo_. Here I am
on familiar ground: the languages of the Latin family have preserved,
with the inevitable modifications, the ancient word _faseolus_.
Now, if I consult my dictionary I find: _faselus_, _faseolus_,
_phaseolus_, haricot. Learned lexicographer, permit me to remark that
your translation is incorrect: _faselus_, _faseolus_ cannot mean
haricot. The incontestable proof is in the Georgics, where Virgil tells
us at what season we must sow the _faselus_. He says:--
Si vero viciamque seres vilemque faselum ...
Haud obscura cadens mittet tibi signa Bootes;
Incipe, et ad medias sementem extende pruinas.
Nothing is clearer than the precept of the poet who was so admirably
familiar with all matters agricultural; the sowing of the _faselus_ must
be commenced when the constellation of Bootes disappears at the set of
sun, that is, in October; and it is to be continued until the middle of
These conditions put the haricot out of the running: it is a delicate
plant, which would never survive the lightest frost. Winter would be
fatal to it, even under Italian skies. More refractory to cold on
account of the country of their origin, peas, broad beans, and vetches,
and other leguminous plants have nothing to fear from an autumn sowing,
and prosper during the winter provided the climate be fairly mild.
What then is represented by the _faselus_ of the Georgics, that
problematical vegetable which has transmitted its name to the haricot in
the Latin tongues? Remembering that the contemptuous epithet _vilis_ is
used by the poet in qualification, I am strongly inclined to regard it
as the cultivated vetch, the big square pea, the little-valued _jaisso_
of the Provencal peasant.
The problem of the haricot stood thus, almost elucidated by the
testimony of the insect world alone, when an unexpected witness gave me
the last word of the enigma. It was once again a poet, and a famous
poet, M. Jose-Maria de Heredia, who came to the aid of the naturalist.
Without suspecting the service he was rendering, a friend of mine, the
village schoolmaster, lent me a magazine in which I read the
following conversation between the master-sonneteer and a lady
journalist, who was anxious to know which of his own works he preferred.
"What would you have me say?" said the poet.
"I do not know what to say, I do not know which sonnet I prefer; I have
taken horrible pains with all of them.... But you, which do you prefer?"
"My dear master, how can I choose out of so many jewels, when each one
is perfect in its beauty? You flash pearls, emeralds, and rubies before
my astonished eyes: how should I decide to prefer the emerald to the
pearl? I am transported by admiration of the whole necklace."
"Well, as for me, there is something I am more proud of than of all my
sonnets, and which has done much more for my reputation than my verses."
I opened my eyes wide, "What is that?" I asked. The master looked at me
mischievously; then, with that beautiful light in his eyes which fires
his youthful countenance, he said triumphantly--
"It is my discovery of the etymology of the word haricot!"
I was so amazed that I forgot to laugh.
"I am perfectly serious in telling you this."
"I know, my dear master, of your reputation for profound scholarship:
but to imagine, on that account, that you were famed for your discovery
of the etymology of haricot--I should never have expected it! Will you
tell me how you made the discovery?"
"Willingly. See now: I found some information respecting the haricot
while studying that fine seventeenth-century work of natural history by
Hernandez: _De Historia plantarum novi orbis_. The word haricot was
unknown in France until the seventeenth century: people used the word
_feve_ or _phaseol_: in Mexican, _ayacot_. Thirty species of haricot
were cultivated in Mexico before the conquest. They are still known as
_ayacot_, especially the red haricot, spotted with black or violet. One
day at the house of Gaston Paris I met a famous scholar. Hearing my
name, he rushed at me and asked if it was I who had discovered the
etymology of the word haricot. He was absolutely ignorant of the fact
that I had written verses and published the _Trophees_."--
A very pretty whim, to count the jewellery of his famous sonnets as
second in importance to the nomenclature of a vegetable! I in my turn
was delighted with his _ayacot_. How right I was to suspect the
outlandish word of American Indian origin! How right the insect was, in
testifying, in its own fashion, that the precious bean came to us from
the New World! While still retaining its original name--or something
sufficiently like it--the bean of Montezuma, the Aztec _ayacot_, has
migrated from Mexico to the kitchen-gardens of Europe.
But it has reached us without the company of its licensed consumer; for
there must assuredly be a weevil in its native country which levies
tribute on its nourishing tissues. Our native bean-eaters have mistaken
the stranger; they have not had time as yet to grow familiar with it, or
to appreciate its merits; they have prudently abstained from touching
the _ayacot_, whose novelty awoke suspicion. Until our own days the
Mexican bean remained untouched: unlike our other leguminous seeds,
which are all eagerly exploited by the weevil.
This state of affairs could not last. If our own fields do not contain
the insect amateur of the haricot the New World knows it well enough. By
the road of commercial exchange, sooner or later some worm-eaten sack
of haricots must bring it to Europe. The invasion is inevitable.
According to documents now before me, indeed, it has already taken
place. Three or four years ago I received from Maillane, in the
Bouches-du-Rhone, what I sought in vain in my own neighbourhood,
although I questioned many a farmer and housewife, and astonished them
by my questions. No one had ever seen the pest of the haricot; no one
had ever heard of it. Friends who knew of my inquiries sent me from
Maillane, as I have said, information that gave great satisfaction to my
naturalist's curiosity. It was accompanied by a measure of haricots
which were utterly and outrageously spoiled; every bean was riddled with
holes, changed into a kind of sponge. Within them swarmed innumerable
weevils, which recalled, by their diminutive size, the lentil-weevil,
The senders told me of the loss experienced at Maillane. The odious
little creature, they said, had destroyed the greater portion of the
harvest. A veritable plague, such as had never before been known, had
fallen upon the haricots, leaving the housewife barely a handful to put
in the saucepan. Of the habits of the creature and its way of going to
work nothing was known. It was for me to discover them by means of
Quick, then, let us experiment! The circumstances favour me. We are in
the middle of June, and in my garden there is a bed of early haricots;
the black Belgian haricots, sown for use in the kitchen. Since I must
sacrifice the toothsome vegetable, let us loose the terrible destroyer
on the mass of verdure. The development of the plant is at the
requisite stage, if I may go by what the _Bruchus pisi_ has already
taught me; the flowers are abundant, and the pods are equally so; still
green, and of all sizes.
I place on a plate two or three handfuls of the infested haricots, and
set the populous heap in the full sunlight by the edge of my bed of
beans. I can imagine what will happen. Those insects which are already
free, and those which the stimulus of the sunshine will presently
liberate, will emerge and take to their wings. Finding the maternal
haricot close at hand they will take possession of the vines. I shall
see them exploring pods and flowers, and before very long they will lay
their eggs. That is how the pea-weevil would behave under similar
But no: to my surprise and confusion, matters do not fall out as I
foresaw. For a few minutes the insects bustle about in the sunlight,
opening and closing their wing-covers to ease the mechanism of flight;
then one by one they fly away, mounting in the luminous air; they grow
smaller and smaller to the sight, and are quickly lost to view. My
persevering attentions have not met with the slightest success; not one
of the weevils has settled on my haricots.
When the joys of liberty have been tasted will they return--to-night,
to-morrow, or later? No, they do not return. All that week, at
favourable hours, I inspect the rows of beans pod by pod, flower by
flower; but never a Bruchus do I see, nor even an egg. Yet the season is
propitious, for at this very moment the mothers imprisoned in my jars
lay a profusion of eggs upon the dry haricots.
Next season I try again. I have at my disposal two other beds, which I
have sown with the late haricot, the red haricot; partly for the use of
the household, but principally for the benefit of the weevil. Arranged
in convenient rows, the two crops will be ready, one in August and one
in September or later.
With the red haricot I repeat the experiment already essayed with the
black haricot. On several occasions, in suitable weather, I release
large numbers of weevils from my glass jars, the general headquarters of
the tribe. On each occasion the result is plainly negative. All through
the season, until both crops are exhausted, I repeat my search almost
daily; but I can never discover a single pod infested, nor even a single
weevil perching on leaf or flower.
Certainly the inspection has not been at fault. The household is warned
to respect certain rows of beans which I have reserved for myself. It is
also requested to keep a look-out for eggs on all the pods gathered. I
myself examine with a magnifying-glass all the haricots coming from my
own or from neighbouring gardens before handing them over to the
housewife to be shelled. All my trouble is wasted: there is not an egg
to be seen.
To these experiments in the open air I add others performed under glass.
I place, in some tall, narrow bottles, fresh haricot pods hanging from
their stems; some green, others mottled with crimson, and containing
seeds not far from mature. Each bottle is finally given a population of
weevils. This time I obtain some eggs, but I am no further advanced;
they are laid on the sides of the bottles, but not on the pods.
Nevertheless, they hatch. For a few days I see the grubs wandering
about, exploring the pods and the glass with equal zeal. Finally one
and all perish without touching the food provided.
The conclusion to be drawn from these facts is obvious: the young and
tender haricot is not the proper diet. Unlike the _Bruchus pisi_, the
female of the haricot-weevil refuses to trust her family to beans that
are not hardened by age and desiccation; she refused to settle on my
bean-patch because the food she required was not to be found there. What
does she require? Evidently the mature, dry, hard haricot, which falls
to earth with the sound of a small pebble. I hasten to satisfy her. I
place in the bottles some very mature, horny pods, thoroughly desiccated
by exposure to the sun. This time the family prospers, the grubs
perforate the dry shell, reach the beans, penetrate them, and henceforth
all goes well.
To judge by appearances, then, the weevil invades the granary. The beans
are left standing in the fields until both plants and pods, shrivelled
by the sun, are completely desiccated. The process of beating the pods
to loosen and separate the beans is thus greatly facilitated. It is then
that the weevil, finding matters to suit her, commences to lay her eggs.
By storing his crop a little late the peasant stores the pest as well.
But the weevil more especially attacks the haricot when warehoused. Like
the Calander-beetle, which nibbles the wheat in our granaries but
despises the cereal while still on the stalk, it abhors the bean while
tender, and prefers to establish itself in the peace and darkness of the
storehouse. It is a formidable enemy to the merchant rather than to the
What a fury of destruction once the ravager is installed in the
vegetable treasure-house! My bottles give abundant evidence of this. One
single haricot bean shelters a numerous family; often as many as twenty
members. And not one generation only exploits the bean, but three or
four in the year. So long as the skin of the bean contains any edible
matter, so long do new consumers establish themselves within it, so that
the haricot finally becomes a mere shell stuffed with excreta. The skin,
despised by the grubs, is a mere sac, pierced with holes as many as the
inhabitants that have deserted it; the ruin is complete.
The _Bruchus pisi_, a solitary hermit, consumes only so much of the pea
as will leave a cell for the nymph; the rest remains intact, so that the
pea may be sown, or it will even serve as food, if we can overcome our
repugnance. The American insect knows nothing of these limitations; it
empties the haricot completely and leaves a skinful of filth that I have
seen the pigs refuse. America is anything but considerate when she sends
us her entomological pests. We owe the Phylloxera to America; the
Phylloxera, that calamitous insect against which our vine-growers wage
incessant war: and to-day she is sending us the haricot-weevil, which
threatens to be a plague of the future. A few experiments gave me some
idea of the peril of such an invasion.
For nearly three years there have stood, on my laboratory table, some
dozens of jars and bottles covered with pieces of gauze which prevent
escape while permitting of a constant ventilation. These are the cages
of my menagerie. In them I rear the haricot-weevil, varying the system
of education at will. Amongst other things I have learned that this
insect, far from being exclusive in its choice, will accommodate itself
to most of our leguminous foods.
All the haricots suit it, black and white, red and variegated, large and
small; those of the latest crop and those which have been many years in
stock and are almost completely refractory to boiling water. The loose
beans are attacked by preference, as being easier to invade, but when
the loose beans are not available those in the natural shelter of their
pods are attacked with equal zest. However dry and parchment-like the
pods, the grubs have no difficulty in attaining the seeds. When attacked
in the field or garden, the bean is attacked in this way through the
pod. The bean known in Provence as the blind haricot--_lou faiou
borgne_--a bean with a long pod, which is marked with a black spot at
the navel, which has the look of a closed and blackened eye, is also
greatly appreciated; indeed, I fancy my little guests show an obvious
preference for this particular bean.
So far, nothing abnormal; the Bruchus does not wander beyond the limits
of the botanical family _Phaseolus_. But here is a characteristic that
increases the peril, and shows us this lover of beans in an unexpected
light. Without the slightest hesitation it accepts the dry pea, the
bean, the vetch, the tare, and the chick-pea; it goes from one to the
other, always satisfied; its offspring live and prosper in all these
seeds as well as in the haricot. Only the lentil is refused, perhaps on
account of its insufficient volume. The American weevil is a formidable
The peril would be much greater did the insect pass from leguminous
seeds to cereals, as at first I feared it might. But it does not do so;
imprisoned in my bottles together with a handful of wheat, barley, rice,
or maize, the Bruchus invariably perished and left no offspring. The
result was the same with oleaginous seeds: such as castor-oil and
sunflower. Nothing outside the bean family is of any use to the Bruchus.
Thus limited, its portion is none the less considerable, and it uses and
abuses it with the utmost energy. The eggs are white, slender, and
cylindrical. There is no method in their distribution, no choice in
their deposition. The mother lays them singly or in little groups, on
the walls of the jar as well as on the haricots. In her negligence she
will even lay them on maize, coffee, castor-oil seeds, and other seeds,
on which the newly born grubs will promptly perish, not finding them to
their taste. What place has maternal foresight here? Abandoned no matter
where in the heap of seeds, the eggs are always in place, as it is left
to the grub to search and to find the points of invasion.
In five days at most the egg is hatched. A little white creature with a
red-brown head emerges. It is a mere speck of a creature, just visible
to the naked eye. Its body is thickened forward, to give more strength
to its implements--its mandibles--which have to perforate the hard
substance of the dry bean, which is as tough as wood. The larvae of the
Buprestis and the Capricornis, which burrow in the trunks of trees, are
similarly shaped. Directly it issues from the egg the wriggling creature
makes off at random with an activity we should hardly expect in one so
young. It wanders hither and thither, eager to find food and shelter as
soon as possible.
Within twenty-four hours it has usually attained both. I see the tiny
grub perforate the horny skin that covers the cotyledons; I watch its
efforts; I surprise it sunk half-way in the commencement of a burrow, at
the mouth of which is a white floury powder, the waste from the
mandibles. It works its way inward and buries itself in the heart of the
seed. It will emerge in the adult form in the course of about five
weeks, so rapid is its evolution.
This hasty development allows of several generations in the year. I have
recorded four. On the other hand, one isolated couple has furnished me
with a family of eighty. Consider only the half of this
number--supposing the sexes to be equal in number--and at the end of a
year the couples issued from this original pair would be represented by
the fortieth power of forty; in larvae they would represent the frightful
total of more than five millions. What a mountain of haricots would be
ravaged by such a legion!
The industry of the larvae reminds us at every point what we have learned
from the _Bruchus pisi_. Each grub excavates a lodging in the mass of
the bean, respecting the epidermis, and preparing a circular trap-door
which the adult can easily open with a push at the moment of emergence.
At the termination of the larval phase the lodgements are betrayed on
the surface of the bean by so many shadowy circles. Finally the lid
falls, the insect leaves its cell, and the haricot remains pierced by as
many holes as it has nourished grubs.
Extremely frugal, satisfied with a little farinaceous powder, the adults
seem by no means anxious to abandon the native heap or bin so long as
there are beans untouched. They mate in the interstices of the heap;
the mothers sow their eggs at random; the young larvae establish
themselves some in beans that are so far intact, some in beans which are
perforated but not yet exhausted; and all through the summer the
operations of breeding are repeated once in every five weeks. The last
generation of the year--that of September or October--sleeps in its
cells until the warm weather returns.
If the haricot pest were ever to threaten us seriously it would not be
very difficult to wage a war of extermination against it. Its habits
teach us what tactics we ought to follow. It exploits the dried and
gathered crop in the granary or the storehouse. If it is difficult to
attack it in the open it would also be useless. The greater part of its
affairs are managed elsewhere, in our storehouses. The enemy establishes
itself under our roof and is ready to our hand. By means of insecticides
defence should be relatively easy.