QUEER MUSICAL INSTRUMENTS
Uncle Paul had placed in the lettuce bed two large pots half full of
water and set into the ground flush with the surface. He said they were
a trap for mole-crickets, which, from the withered appearance of some
of the plants, he suspected were in the garden. One morning, on going
to look into the pots, Emile found three drowned mole-crickets in them.
That evening Uncle Paul told the children about these creatures.
“The insects Emile found in the trap,” said he, “are called
mole-crickets from their habit of burrowing into the ground like moles
and from their resembling in certain other ways ordinary crickets. The
mole-cricket has the common cricket’s long and slender antennæ, its two
flexible filaments at the end of the abdomen, and its rough wings which
are rubbed against each other so as to make a sort of singing noise. It
is a formidable ravager of our gardens.”
“Do crickets really chirp with their wings?” asked Emile, in surprise.
“Yes, my boy. In chirping the cricket raises its wings, which are dry
and wrinkled, and rubs the edges together vigorously. The other
chirping insects do about the same. The vineyard grasshopper, the one
with the large green and yellow belly, has on its back two round scales
which fit together and rub against each other. They constitute its
musical instrument. Other grasshoppers play the violin; that is to say,
they scrape the rough edges of their wings with their big curved thighs
as bows or fiddle-sticks. The cicada has under its stomach in a double
cavity, protected by covers capable of being raised more or less, two
dry and shiny membranes stretched as taut as drumheads. The insect
sings by making these vibrate in their cases.”
“Does the mole-cricket say cree-cree like the ordinary cricket?”
“No; its song has a monotonous sound, being a sort of sharp buzzing,
rather subdued, and continuous.”
“And why does the mole-cricket sing? What an ugly creature with its
little crafty eyes, short wings, big stomach, and frightful fore feet!”
“It sings to cheer its solitude and call its mate. You think it ugly; I
find it admirably equipped for the work it has to do. It lives in the
ground, just as moles do, and like them it is provided with a special
tool for digging in the earth and cutting the roots that bar its way.
Have you ever noticed a mole’s fore feet? They are broadly
shovel-shaped and furnished with strong claws. The mole-cricket’s fore
feet are very much like them, being short and wide and edged with
saw-teeth. With this pair of powerful tools the insect digs its
subterranean tunnels.”
“Then that,” said Jules, “must be the reason for calling it a
mole-cricket: it has the mole’s wide feet for digging.”
“I should like to know,” Emile interposed, “what the mole and
mole-cricket do under the ground.”
“They hunt for worms and all kinds of insects for food. In their
subterranean operations both cut with their fore feet the roots that
obstruct their progress, but the mole, exclusively carnivorous, does
not eat them, whereas the mole-cricket, living on both animal and
vegetable matter, nibbles them at its pleasure. Nor does it disdain a
tender lettuce leaf when at night it comes up above ground to get a
little air and cultivate the acquaintance of its neighbors. Hence the
mole-cricket does a great deal of damage in gardens by laying bare the
roots of young plants when it is boring its tunnels, or by severing
these roots with the saw-like edges of its feet, or by nibbling them
when hungry.
“Not far beneath the surface of the ground the female makes her nest,
which is in the form of a hollow ball of earth about as large as your
fist. In this cavity, after it has been carefully smoothed and
prepared, she lays her eggs, to the number of three or four hundred,
after which she remains in the neighborhood as if to watch over them.
When first hatched the young ones are white all over and look like big
ants. When the ground is spaded these nests should always be destroyed.
“The mole-cricket’s domain is composed of passages running down to a
greater or less distance, with hunting galleries just under the
surface. To dislodge the insect from its retreat a little oil is poured
into the hole where it is thought to have taken refuge, and then plenty
of water from the watering-pot, until all the passages are inundated.
Threatened with suffocation by the oil, which interferes with its
breathing, the mole-cricket soon comes to the surface. One can also use
the trap that I have found serviceable. A wide and deep vessel is set
into the ground, level with the surface, and half filled with water.
Attracted by the coolness, the mole-crickets fall in and drown in the
course of their nocturnal promenades. Sometimes, again, at the approach
of cold weather holes are dug here and there and filled with horse
manure. The warmth of the manure is agreeable to the mole-crickets, and
they come and hide in it for the winter. When cold weather begins,
these lurking-places are searched and the foolish occupants destroyed.
“The mole-cricket, the house-cricket, the locust, and the grasshopper
belong to a family of insects called orthoptera, so named from their
straight wings; that is, the lower wings, those used for flying, are
folded lengthwise in a straight line when in repose, like a closed fan.
Look at the red or blue wings of the crickets that abound in autumn, in
dry grass, and you will see them neatly folded lengthwise, while the
upper wings, which are somewhat leathery, are usually brought together
in the shape of a roof. Many, but not all, of the orthoptera have thick
thighs ending in long and bristly legs that serve for jumping. Finally,
some of these insects have at the end of the abdomen a terebra,
commonly called a sword, its office being to lay the eggs in the
ground.
“One of these orthoptera commits terrible ravages in Africa. It is the
migratory locust, so named because it assembles in immense swarms and
migrates to another region when food fails. The migrating swarm takes
flight as at a given signal and moves through the air like a great
cloud, even intercepting the light of the sun. Sooner or later the
devastating hordes swoop down like a living storm on the cultivated
fields of some province, and in a few hours leaves, grain, pastures,
fields, all are browsed bare as if swept by a conflagration, the ground
showing not a green blade of any kind surviving.”
“If those ravenous locusts travel like that,” said Jules, “couldn’t
they come here?”
“Driven by a favorable wind, clouds of locusts do sometimes cross the
Mediterranean and alight in our southern departments. At various times
the territory of Arles has suffered this terrible visitation. It should
be added that if the country suits them where they chance to alight,
the locusts lay their eggs there, and from these there springs a legion
of devourers more numerous than the first. To lessen the ravages of
this second generation search is made for the eggs, which the locust
lays in a cylindrical hole running a few centimeters into the ground.
In 1832, in the neighborhood of Arles, nearly four thousand kilograms
of eggs were gathered besides bagfuls of the insects themselves. It
takes eighty thousand eggs to make a kilogram; hence in that harvest of
eggs there were three hundred and twenty million locusts destroyed
before they were born. Imagine the ravages of such a swarm of devourers
alighting on the vegetation of any given district. Before so terrible a
scourge man bows his head and acknowledges his powerlessness, the
insect ravager overwhelming him by its very numbers.
“How many other ravagers there are, my children, besides locusts, that
by their inconceivable multitude defy our attempts to defend ourselves!
You are now in a position to realize somewhat the serious nature of
these devastations when you think of all the moths and caterpillars and
worms, all the creeping and burrowing and flying insects, of all shapes
and sizes and appetites, that attack our gardens and fields. They would
certainly gain the upper hand if we had to depend on ourselves in
combating them. But fortunately we are most ably assisted in this
contest.”
NOTES
[1] See “Field, Forest, and Farm.”
[2] See “The Story-Book of Science.”
[3] The French campagnol is translated in this book by meadow-mouse.
The term vole, another rendering, is purely British and too
uncommon in America to warrant its use in these pages.—Translator.
[4] A name given to the cat in La Fontaine’s “Fables.”—Translator.
[5] Audubon: “Ornithological Biography,” I. 160–162.—Translator.
[6] Dupont de Nemours.
[7] See “The Story-Book of Science.”
[8] From “Le Crapaud” (“The Toad”), by Victor Hugo.—Translator.
[9] A liter is slightly more than a quart, a hectoliter a little more
than one hundred quarts.—Translator.
[10] See “The Secret of Everyday Things.”