CLEVER MISCHIEF-MAKERS
“Here is another weevil I have to show you,” began Uncle Paul the next
day. “What do you think of it? Note its shiny violet coat with glints
of blue that bring out the delicate down with which the whole body is
covered. The purple of our richest silks is not so magnificent.”
“Oh, the pretty little thing!” cried Emile. “What can it do with its
beautiful clothes?”
“Nothing to our advantage, my boy. Fine clothes do not make useful
citizens, either among insects or among men. The bee’s dress is a
modest brown, and the bee works at honey-making; the dress of the
weevil I show you here is very handsome, but the elegant creature lives
at our expense. If you have in your garden any fine plums or pears or
apples, it gets ahead of you in harvesting the crop; it does not even
wait for the fruit to ripen, so fearful is it of being too late. In
June it punctures with its pointed snout the young apple or pear or
plum and lays an egg in the unripe flesh. The fruit thus treated feeds
the larva for some time, and then dries up and falls off. Then the worm
emigrates, leaves the plum that has nourished it, and buries itself in
the ground to reappear the next spring as a perfect insect.”
“I should like to know the name of this plum-pricker; I’d teach it to
behave if I got hold of it.”
“It is called, very inappropriately, the rhynchites bacchus.”
“Bacchus, if I remember rightly,” said Jules, “is the god of wine.”
“Exactly; and that is where the word is out of place here. No doubt the
first observers confounded the weevil of our orchards with that of our
vineyards, giving to the former the name that should belong to the
latter. But the mistake has been made and we can’t do anything about it
now. Let us keep the names as they are, but not confound the two
weevils so different in appearance and habits. The weevil that rolls
the vine leaves is hairless and of a golden-green color; the other is
all covered with hairs and its color is a lustrous violet. To avoid
confusion in our talk, why should we not call this latter insect the
plum-weevil, or the pear-weevil?”
“That would be a good name for it,” assented Louis.
“I shall just call it the plum-pricker,” declared Emile.
“There is no reason why you should not,” his uncle agreed. “Now let us
pass on to another member of the family. See what widely dissimilar
habits there are in a group of insects in which the expert eye can
nevertheless perceive close resemblances, I might almost say a near
relationship. Some roll grape or oak or poplar leaves; others puncture
fruit with the beak; this one here that I am going to tell you about
severs—partly, never wholly—the tips of young and tender shoots of
various fruit-trees. Hence they are commonly known as bud-cutters. It
is a weevil, but much smaller than that of the grapevine. The adjective
conical is given to it on account of the shape of its thorax or
breastplate, which tapers a little toward the front like a sugar-loaf.
It is rather lustrous and of a blue color shading into green.
“It shows remarkable cleverness in its operations. Establishing itself
in spring on a pear, cherry, apricot, plum, or hawthorn tree,
indifferently, it selects one by one the shoots that suit it, and in
the not yet unfolded terminal bud it bores with its beak a tiny hole,
in which it lays an egg. But it appears that the young larva requires a
diet especially prepared for it, one that is slightly decomposed, and
not the bitter juices of the vigorously growing shoot. Have not we
ourselves similar tastes? Do we eat medlars and sorb-apples just as
they come from the tree? No indeed; they must first be left to ripen on
straw, even to decay a little.”
“Then they are first-rate,” was Emile’s pronouncement; “but before that
they are horrid.”
“That is what the larva of the weevil would say about the shoot on
which it has just hatched out. Before being treated it is bitter, it
rasps the throat and sets the mandibles on edge; after treatment it is
delicious.”
“Yet it doesn’t put the branch to ripen on straw as we do medlars?”
“No. In most cases larvæ show no ingenuity whatever; they eat like
gluttons and without a thought for anything but eating. You know well
enough that giving oneself up to gorging is hardly the way to improve
the mind. For these larvæ, then, a ready-made pap has to be provided,
as otherwise, not knowing how to prepare it themselves, they would
stupidly starve to death. And who prepares the food and makes it just
right for them? The mother, if you please, the mother whose great and
only occupation it is to provide for the future needs of her unborn
young. She makes it her business to find for them food that not only
has no nourishment in it for herself, but which she dislikes; she
denies herself the enjoyment of flowery fields and summer sunshine to
devote all her energies to arduous labors that are of no advantage to
her personally; and when she has spent her little span of life at this
hard task she retires into a corner and dies content: the table is set,
the young larvæ will not lack for food.
“When you see the weevil on a vine leaf, sparkling like a precious gem,
do not think it is there to enjoy itself. It is spending itself in the
difficult undertaking of sawing the leaf half-way through at the stem,
after which it will roll the leaf into a sheath to serve as lodging and
first food for the larvæ. Its whole life of two or three weeks is given
to this work. How can it benefit the insect itself to saw leaf stems
and make the leaves wither in the sun and then roll them up? In no way
whatever; the weevil does not eat these leaves or lodge in the sheath
made by rolling one of them up. It spends its energies in this work
solely for the larvæ that are to be hatched out after its death. Have
you ever reflected, my children, on this perpetual miracle,—the miracle
of a mother living only for her little ones, little ones that she is
destined never to see? I will not conceal from you that every time I
think of this maternal foresight, this laborious preparation for a
future unknown to the mother herself, I feel myself deeply moved. The
All-seeing Eye is there.
“In a way peculiar to itself the conical weevil makes ready the pap
that is to feed its family. The larvæ, as I said, require the mild
juices of a shoot that has been deprived of its natural vigor. What
does the mother do to put the branch in the proper condition? Under the
spot where the egg is laid she cuts away the bark and some of the wood
in a circle, with her fine mandibles, leaving the shoot supported only
by the central portion of the stem. The sap no longer circulating
beyond this girdle, the leaves affected soon wither and the entire tip
of the shoot turns black and acquires that state of decay best liked by
the new-born grub.”
“I knew how to ripen medlars on straw,” said Emile, “but I should have
been puzzled to tell how to ripen a branch of a tree. What curious
creatures those are, with their clever ways of doing things! One can do
one thing and another can do another, and it is always ingenious and
never the same.”
“It is vexatious that all too often the insect’s labors involve harm
and loss to us. When a fruit-tree has been operated on by the conical
weevil you can see, in the month of May, the tips of the shoots hanging
withered and blackened, after which they dry up and fall.”
“Do the larvæ stay in the tips of the fallen branches?” asked Jules.
“What would they do there? Food would fail them, and so they bury
themselves in the ground to finish their growth and pass the winter
there snugly and safely. In the spring their metamorphosis takes
place.”
“Then to guard against insect ravages for the next year,” said Louis,
“the withered shoots that hang from the trees should be collected and
burned while the larvæ are still there.”
“Yes, that is the best thing to do.”