ANOTHER PROBER (PERFORATOR)





What can he be called, this creature whose style and title I dare

not inscribe at the head of the chapter? His name is

Monodontomerus cupreus, SM. Just try it, for fun: Mo-no-don-to-

me-rus. What a gorgeous mouthful! What an idea it gives one of

some beast of the Apocalypse! We think, when we pronounce the

word, of the prehistoric monsters: the mastodon, the mammoth, the

ponderous megatherium. Well, we are misled by the scientific

label: we have to do with a very paltry insect, smaller than the

common gnat.



There are good people like that, only too happy to serve science

with resounding appellations that might come from Timbuktu; they

cannot name you a midge without striking terror into you. O ye

wise and revered ones, ye christeners of animals, I am willing, in

my study, to make use--but not undue use--of your harsh

terminology, with its conglomeration of syllables; but there is a

danger of their leaving the sanctum and appearing before the

public, which is always ready to show its lack of deference for

terms that do not respect its ears. I, wishing to speak like

everybody else, so that I may be understood by all, and persuaded

that science has no need of this Brobdignagian jargon, make a

point of avoiding technical nomenclature when it becomes too

barbarous, when it threatens to lumber the page the moment my pen

attempts it. And so I abandon Monodontomerus.



It is a puny little insect, almost as tiny as the midges whom we

see eddying in a ray of sunshine at the end of autumn. Its dress

is golden bronze; its eyes are coral red. It carries a naked

sword, that is to say, the sheath of its drill stands out slantwise

at the tip of its belly, instead of lying in a hollow groove along

the back, as it does with the Leucospis. This scabbard holds the

latter half of the inoculating filament, which extends below the

animal to the base of the abdomen. In short, its utensil is that

of the Leucospis, with this difference, that its lower half sticks

out like a rapier.



This mite that bears a sword upon her rump is yet another

persecutor of the mason bees and not one of the least formidable.

She exploits their nests at the same time as the Leucospis. I see

her, like the Leucospis, slowly explore the ground with her

antennae; I see her, like the Leucospis, bravely drive her dagger

into the stone wall. More taken up with her work, less conscious

perhaps of danger, she pays no heed to the man who is observing her

so closely. Where the Leucospis flies, she does not budge. So

great is her assurance that she comes right into my study, to my

work table, and disputes my ownership of the nests whose occupants

I am examining. She operates under my lens, she operates just

beside my forceps. What risk does she run? What can one do to a

thing so very small? She is so certain of her safety that I can

take the Mason's nest in my hand, move it, put it down and take it

up again without the insect's raising any objection: it continues

its work even when my magnifying glass is placed over it.



One of these heroines has come to inspect a nest of the

Chalicodoma of the Walls, most of whose cells are occupied by the

numerous cocoons of a parasite, the Stelis. The contents of these

cells, which have been partially ripped up to satisfy my

curiosity, are very much exposed to view. The windfall appears to

be appreciated, for I see the dwarf ferret about from cell to cell

for four days on end, see her choose her cocoon and insert her awl

in the most approved fashion. I thus learn that sight, although

an indispensable guide in searching, does not decide upon the

proper spot for the operation. Here is an insect exploring not

the stony exterior of the mason's dwelling, but the surface of

cocoons woven of silk. The explorer has never found herself

placed in such circumstances, nor has any of her race before her,

every cocoon, under normal conditions, being protected by a

surrounding wall. No matter: despite the profound difference in

the surfaces, the insect does not waver. Warned by a special

sense, an undecipherable riddle to ourselves, it knows that the

object of its search lies hidden under this unfamiliar casing.

The sense of smell has already been shown to be out of the

question; that of sight is now eliminated in its turn.



That she should bore through the cocoons of the Stelis, a parasite

of the mason bee, does not surprise me at all: I know how

indifferent my bold visitor is to the nature of the victuals

destined for her family. I have noticed her presence in the homes

of bees differing greatly in size and habits: Anthophorae, Osmiae,

Chalicodomae, Anthidia. The Stelis exploited on my table is one

victim more; and that is all. The interest does not lie there.

The interest lies in the maneuvers of the insect, which I am able

to follow under the most favorable conditions.



Bent sharply at right angles, like a couple of broken matches, the

antennae feel the cocoon with their tips alone. The terminal joint

is the home of this strange sense which discerns from afar what no

eye sees, no scent distinguishes and no ear hears. If the point

explored be found suitable, the insect hoists itself on tiptoe so

as to give full scope to the play of its mechanism; it brings the

tip of the belly a little forward; and the entire ovipositor--

inoculating-needle and scabbard--stands perpendicular to the

cocoon, in the center of the quadrilateral described by the four

hind legs, an eminently favorable position for obtaining the

maximum effect. For some time, the whole of the awl bears on the

cocoon, feeling all round with its point, groping about; then,

suddenly, the boring needle is released from its sheath, which

falls back along the body, while the needle strives to make its

entrance. The operation is a difficult one. I see the insect make

a score of attempts, one after the other, without succeeding in

piercing the tough wrapper of the Stelis. Should the instrument

not penetrate, it retreats into its sheath and the insect resumes

its scrutiny of the cocoon, sounding it point by point with the

tips of its antennae. Then further thrusts are tried until one

succeeds.



The eggs are little spindles, white and gleaming like ivory, about

two-thirds of a millimeter in length. They have not the long,

curved peduncle of the Leucospis' eggs; they are not suspended from

the ceiling of the cocoon like these, but are laid without order

around the fostering larva. Lastly, in a single cell and with a

single mother, there is always more than one laying; and the number

of eggs varies considerably in each. The Leucospis, because of her

great size, which rivals that of her victim, the Bee, finds in each

cell provisions enough for one and one alone. When, therefore,

there is more than one set of eggs in any one cell, this is due to

a mistake on her part and not a premeditated result. Where the

whole ration is required for the meals of a single grub, she would

take good care not to install several if she could help it. Her

competitor is not called upon to observe the same discretion. A

Chalicodoma grub gives the dwarf the wherewithal to portion a score

of her little ones, who will live in common and in all comfort on

what a single son of the giantess would eat up by himself. The

tiny boring engineer, therefore, always settles a numerous family

at the same banquet. The bowl, ample for a dozen or two, is

emptied in perfect harmony.



Curiosity made me count the brood, to see if the mother was able to

estimate the victuals and to proportion the number of guests to the

sumptuousness of the fare provided. My notes mention fifty-four

larvae in the cell of a masked Anthophora (Anthophora personata).

No other census attained this figure. Possibly, two different

mothers had laid their eggs in this crowded habitation. With the

Mason bee of the Walls, I see the number of larvae vary, in

different cells, between four and twenty-six; with the mason bee of

the Sheds, between five and thirty-six; with the three-horned

Osmia, who supplied me with the largest number of records, between

seven and twenty-five; with the blue Osmia (Osmia cyanea, KIRB.),

between five and six; with the Stelis (Stelis nasuta), between four

and twelve.



The first return and the last two seem to point to some relation

between the abundance of provisions and the number of consumers.

When the mother comes upon the bountiful larva of the masked

Anthophora, she gives it half-a-hundred to feed; with the Stelis

and the blue Osmia, niggardly rations both, she contents herself

with half-a-dozen. To introduce into the dining room only the

number of boarders that the bill of fare will allow would certainly

be a most deserving performance, especially as the insect is placed

under very difficult conditions to judge the contents of the cell.

These contents, which lie hidden under the ceiling, are invisible;

and the insect can derive its information only from the outside of

the nest, which varies in the different species. We should

therefore have to admit the existence of a particular power of

discrimination, a sort of discernment of the

species, which is recognized as large or small from the outward

aspect of its house. I refuse to go to this length in my

conjectures, not that instinct seems to me incapable of such feats,

but because of the particulars obtained from the three-horned Osmia

and the two mason bees.



In the cells of these three species, I see the number of larvae put

out to nurse vary in so elastic a fashion that I must abandon all

idea of proportionate adjustment. The mother, without troubling

unduly whether there be an excess or a dearth of provisions for her

family, has filled the cells as her fancy prompted, or rather

according to the number of ripe ovules contained in her ovaries at

the time of the laying. If food be over-plentiful, the brood will

be all the better for it and will grow bigger and stronger; if food

be scarce, the famished youngsters will not die, but will remain

smaller. Indeed, with both the larva and the full grown insect, I

have often observed a difference in size which varies according to

the density of the population, the members of a small colony being

double the size of their overcrowded neighbors.



The grubs are white, tapering at both ends, sharply segmented and

covered all over their bodies with a coat of fine, soft hairs which

is invisible except under the lens. The head consists of a little

knob much smaller in diameter than the body. In this head, the

microscope reveals mandibles consisting of fine spikes of a tawny

red, which spread into a wide, colorless base. Deprived of any

indentation, incapable of chewing anything between their awl-shaped

ends, these two tools serve at best to fix the grub slightly at

some point of the fostering larva. Useless for carving, therefore,

the mouth is a pure osculatory sucker, which drains the provisions

by a process of exudation through the skin. We see here repeated

what the Anthrax and the Leucospis have already shown us: the

gradual exhaustion of a victim which the parasite consumes without

killing it.



It is a curious spectacle even after that of the Anthrax. We have

here twenty or thirty starvelings, all with their mouths pressed,

as for a kiss, to the body of the plump larva, which, from day to

day, fades and shrinks without the least appreciable wound, thus

keeping fresh until reduced to a shriveled slough. If I disturb

the gluttonous swarm, all, with a sudden recoil, let go, drop off

and flounder around the foster mother. They are no less prompt in

resuming their savage kisses. I need not add that neither at the

point where they leave off nor at the point where they recommence

is there the faintest trace of liquid. The oily exudation occurs

only when the pump is at work. To linger over this strange method

of feeding is superfluous after what I have said about the Anthrax.



The appearance of the full grown insect takes place at the

beginning of summer, after nearly a whole year's stay in the

invaded dwelling. The large number of inhabitants of one and the

same cell led me to think that the work of deliverance ought to

present a certain interest. They are all equally anxious to clear

the walls of the prison at the earliest possible moment and to come

forth into the great festival of the sun: do they all at the same

time, in a confused horde, attack the ceiling which has to be

pierced? Is the work of deliverance arranged in the general

interest? Or is individual selfishness the only rule? These are

the questions which observation will answer.



A little in advance of the proper season, I transfer each family

into a short glass tube, which will represent the natal cell. A

good, thick cork, quite a centimeter deep, is the obstacle to be

pierced for an outlet. Well, instead of the mad haste and the

ruinous lack of organization which I expected to find, my broods

show me in their glass prison an exceedingly well regulated

workshop. One insect, one only, works at perforating the cork.

Patiently, with its mandibles, grain by grain, it digs a tunnel the

width of its body. The gallery is so narrow that, in order to

return to the tube, the worker has to move backwards. It is a slow

process; and it takes hours and hours to dig the hole, a hard job

for the frail miner.



Should her fatigue become too great, the excavator leaves the

forefront and mingles with the crowd, to polish and dust herself.

Another, the first neighbor at hand, at once takes her place and is

herself relieved by a third when her task is done. Others again

take their turn, always one at a time, so much so that the works

are never at a standstill and never overcrowded. Meanwhile, the

multitude keeps out of the way, quietly and patiently. There is no

anxiety as to the deliverance. Success will come: of that they are

all convinced. While waiting, one washes her antennae by passing

them through her mouth, another polishes her wings with her hind

legs, another frisks about to while away the period of inaction.

Some are making love, a sovran means of killing time, whether one

be born that day or twenty years ago.



Some, I said, make love. These favored ones are rare; they hardly

count. Is it through indifference? No, but the gallants are

lacking. The sexes are very unequally represented in the

population of a cell: the males are in a wretched minority and

sometimes even completely absent. This poverty did not escape the

older observers. Brulle [Gaspard August Bru11e (1809-1873)], the

author of many works on natural history and one of the founders of

the Societe entomologique de France), the only author whom I am

able to consult in my hermitage, says, literally: 'The males do not

appear to be known.'



I, for my part, know them; but, considering their feeble number, I

keep asking myself what part they play in a harem so

disproportionate to their forces. A few figures will show us what

my hesitations are based upon.



In twenty-two Osmia cocoons (Osmia tricornis), the total census of

the inmates yields three hundred and fifty-four, of whom forty-

seven are males and three hundred and seven females. The average

number of inmates, therefore, is sixteen individuals; and there are

six females at least to one male. This disparity is maintained, in

more or less marked proportions, whatever the species of the bee

invaded. In the cocoons of the Mason bee of the Sheds, I discover

the average proportion to be six females to one male; in those of

the Mason bee of the Walls, I find one male to fifteen females.



These facts, which I am unable to state with any greater precision,

are enough to give rise to the suspicion that the males, who are

even tinier dwarfs than the females and who, moreover, like all

insects, are injured by a single act of pairing, must, in most

cases, remain strangers to the females. Can the mothers, in fact,

dispense with their assistance, without being deprived of offspring

on that account? I do not say yes, but I do not say no. The

duality of the sexes is a hard problem. Why two sexes? Why not

just one? It would have been much simpler and saved a great deal

of foolery. Why such a thing as sex, when the tuber of the

Jerusalem artichoke can do without it? These are the pregnant

questions suggested to me, in the end, by Monodontomerus cupreus,

the insect so infinitesimal in body and so overpowering in name

that I had really vowed never to speak of it again by its official

designation.





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