“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, [[389]]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.
Migratory Locust
(About half natural size)
“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, [[390]]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! [[391]]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.”