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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

emphatically,
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

leguminous seeds.



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

haricot.



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

the winter.



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[9] 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,

_Bruchus lenti_.



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

experiment.



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

conditions.



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

peasant.



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

experimentalist.



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.



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