NUT-WEEVILS AND FLOWER-WEEVILS
“Ha, you rascal, I’ve caught you at it now, eating my hazelnuts!” cried
Louis one day on seeing a weevil piercing with its long beak a still
tender young nut. “I’ve caught you at it. But first I’ll learn all
about you, and then we’ll have a reckoning.”
The weevil was placed in a paper cornucopia together with some pierced
hazelnuts, and in his first spare moment Louis hastened to Uncle Paul’s
house, his cheeks flushed with excitement. Little Louis was very fond
of hazelnuts, and to catch in the very act the insect that attacks them
was a very serious matter, to his thinking. In the evening Uncle Paul
had his usual audience around him to listen to his account of the
hazelnut-weevil.
“Here is the little insect Louis has caught,” he began. “Look at its
beak a moment.”
“What a nose!” exclaimed Emile. “Oh, what a nose! It is as slender as a
hair and very long and turned back at the end.”
“Doesn’t it look as if it were smoking a long pipe, as I said the other
day?” asked Louis.
“See, Uncle,” Emile pointed out, “how close together its eyes are; they
almost touch each other, and the insect seems to be squinting. How
funny it is, with its nose like a pipe-stem and its squinting eyes!”
“Where is its mouth?” asked Jules.
“At the very end of what Emile calls its long nose,” his uncle replied.
“How does it manage to eat? Food must have a hard time getting through
that stem not so big around as a thread.”
“Yes, how does it manage to eat?” Emile chimed in. “I should be in a
terrible fix if I had to take my food through a straw as long as
myself.”
“The weevil is obliged to exercise moderation; at the most it drinks
with its beak only a few drops of sap from the hazelnut-tree it
inhabits. But if the weevil is temperate in its diet, the larva of the
weevil eats with a good appetite: it demands the whole kernel of a
hazelnut, and it is on purpose to give the larva this food that the
weevil is provided with the long beak that astonishes you. The perfect
insect, I repeat, lives much more for its future family than for
itself, its equipment being designed with reference to the future of
its young. If the weevil had to think merely of its own food its
trumpet would be highly inconvenient; but it must above all look out
for the well-being of its larvæ, and to make provision for that, the
creature’s long and slender beak is a wonderful tool, serving as a fine
gimlet for boring through the nutshell so that the egg may be laid in
the very meat itself and the larva be hatched out in the lap of
plenty.”
“That must be a long, hard job for so fine a gimlet,” Jules remarked.
“Not at all. The tiny mandibles at the end of the trumpet bite the
shell almost as easily as an edged tool of steel would do it; and
moreover the weevil chooses its time. It is in May, when the hazelnuts
are beginning to grow and their shells are soft, that the task is
undertaken. The insect attacks the nut at the base through the green
covering called the cup. As soon as the hole is made, an egg is laid
inside the nut and in a week the larva is hatched out. It is a legless
worm, white with a red head. As the grub eats very little at first, the
hazelnut continues to grow and its kernel to ripen, though gnawed
little by little. When August comes, the store of provision is
exhausted and the wormy nut lies on the ground. Then the worm, its
mandibles strong by this time, makes a round hole in the empty shell
and, leaving the nut, buries itself in the ground, where it undergoes
transformation the following spring.”
“When I am cracking nuts with my teeth,” said Emile, “I once in a while
bite into something bitter and soft.”
“That is the grub of the weevil.”
“Pah! The nasty thing!”
“How can I keep the creatures off my hazelnut-trees?” asked Louis.
“That is very simple. Gather the wormy nuts, which sooner or later fall
to the ground just as does fruit attacked by insects. If they are not
pierced with a large hole the worm is still there. By burning them you
destroy the weevils of the following year.”
“But this year’s weevils will be left.”
“No, for it is a rule that insects die soon after laying their eggs.”
“You haven’t told us the name of this hazelnut-eater,” said Jules.
“It is called the hazelnut-balaninus or hazelnut-weevil, and you can
easily recognize it by its very fine, long, and recurved beak, as also
by the yellowish-gray down that covers the whole of the insect.
“Another balaninus, smaller but of the same shape and color, lives in
acorns in its larva state, and is known as the oak-balaninus. A third,
not very often seen around here, lives in cherry-stones. It is the
cherry-balaninus.”
“How different they all are in their ways of living!” Jules remarked.
“The grain-weevil gnaws the kernels of grain; the vine-weevils and
fruit-weevils roll leaves or prick pears and plums or cut the buds; and
now here are the nut-weevils that attack the hazelnut-meat, the
cherry-stone, and the acorn. Are there any that eat flowers?”
“Indeed there are. No part of a plant is spared by insects. The
apple-tree, the pear-tree, and the cherry-tree have each its peculiar
weevil that in its larva state lives at the expense of the flower buds.
These ravagers are called by a Greek name meaning flower-eaters. See
this apple-tree weevil, the one most familiar to us. It is brown, with
a small white stripe edged with black and placed slantwise on the end
of each wing sheath. Beginning in April, it spreads over the
apple-trees and pierces the flower buds with its fine beak, laying an
egg in each one. A week later the larva is hatched out, and immediately
the little worm begins to gnaw the flower that is curled up in the bud.
Only the outside covering is left intact by this devourer. Of course a
bud that has had its heart eaten out cannot blossom, and so flower and
fruit are both lost. The damaged buds, being gnawed only within, keep
their shape and take in drying the appearance of cloves.”
“Those cloves that Mother Ambroisine puts in stews?” asked Emile.
“The same.”
“What are cloves?”
“They are, as I have already told you, [10] the buds or unopened
flowers of the clove-tree, an aromatic bush growing in hot countries.
They are gathered before opening and are dried in the sun.”
“I see why buds pricked by the flower-weevil look like cloves. In both
cases they are buds that have dried up without opening.”
“The larva of the flower-weevil, like those of weevils in general, is a
tiny legless worm, white in color. It does not leave the bud it has
gnawed when this falls from the tree. The larva of the nut-weevil
leaves its nut by boring a hole through the shell, that of the conical
weevil leaves the fallen shoot, the vine-weevil lets itself drop out of
its rolled leaf, and all three bury themselves in the ground to pass
the winter in safety and be transformed the following spring. The larva
of the flower-weevil is more expeditious: its change into an insect
takes place as soon as it has eaten its bud, so that there is no need
for it to leave its quarters. As animals never do anything without a
purpose, the grub remains shut up in the dry bud. Six weeks after the
egg is laid the larva emerges transformed into a perfect insect and
flits from one apple-tree to another all summer. Then comes the
winter.”
“That must be a trying time,” said Jules.
“Many perish, but others survive, hidden under moss, in the cracks of
bark, or among dry leaves. Indeed, there are plenty of them left to
destroy the buds on our apple-trees when spring comes.
“The flower-weevil of the pear-tree and that of the cherry-tree
resemble the one I have just shown you, and their habits are exactly
the same.
“It is not easy to get rid of these flower-destroyers. If one had only
a few trees to take care of, and those easy to get at in every part,
one could if necessary gather and burn the dry buds inhabited by the
larvæ. By this painstaking process some of the following year’s fruit
might be saved; but not even so should we get rid of all the
flower-weevils, as these insects fly well and far and they would come
from the surrounding region after we had destroyed all our own.
Besides, the gathering of injured buds is impracticable on a large
scale.”
“Will these little flower-eaters come to be masters of our orchards?”
asked Jules. “Will they destroy our apples and pears in the bud, and
can’t we do anything to prevent it?”
“They would indeed be masters had we not vigilant guards, sharp-eyed
helpers, that from sunrise to sunset lie in wait for insects and hunt
them with a patience, skill, and industry that none of us would be
capable of.”
“You mean the birds?” said Emile.
“Yes, the birds. When you see on an apple-tree in bloom a little bird
hopping from branch to branch, warbling and pecking, thank God, my
children, for giving us the charming creature that with every peck of
its beak delivers us from an enemy.”