[Contents]CHAPTER LIITHE INCHWORMOne day Uncle Paul was in his garden engaged in an operation on his pear-trees that greatly puzzled Emile and Jules. He had a pot of black, sticky stuff with a strong smell, and was smearing it with a brush all around the base of the trees. Oh, how One-eyed John would have laughed if he had peeped through the hedge and seen Uncle Paul daubing the foot of his pear-trees with black! But he would have been greatly in the wrong, as is proved by what the boys’ uncle said to them that same evening.“What do you call that stuff you were putting on the trees this morning?” Jules inquired.“It is called tar, and is a substance derived from coal. To make illuminating gas coal is put into large cast-iron vessels and heated red-hot, all outside air being excluded meanwhile. The heat decomposes the coal, which cannot burn for want of air. The products of this decomposition are illuminating gas, tar, and coke, this last being a kind of coal of metallic appearance, very porous and light. The gas and the tar are drawn off through a pipe, the coke remaining in the cast-iron vessel. Tar is a very black, sticky substance with a strong odor repugnant to insects.”[375]“Then you put a coating of it around the tree trunks to keep off insects?”“Certain moths whose caterpillars I fear came through my hedge. The girdle of tar put on at the base of the trunk is to prevent their climbing to the branches to lay their eggs. In that way I protect the fruit-trees from the caterpillars that a little later would destroy the foliage.”“But moths can fly well enough, and your tar wouldn’t stop them. If they can’t reach the branches by climbing the trunk they will fly up to them.”“For a moth that flies, agreed. If on the contrary it cannot fly, but has to content itself with walking, is it not true that the coating of tar encircling the foot of the tree trunk will prove an impassable obstacle? In the first place, the smell of tar is offensive to the moth, and then if it ventures on the sticky girdle it will infallibly become entangled and die, stuck fast in the tar.”“That is plain,” assented Louis. “But are there any moths that can’t fly?”“There are.”“Are the lazy things afraid to use their wings?” asked Emile. “Perhaps they think it’s too much trouble.”“How could they use them? They haven’t any to use, poor things.”“That accounts for it, then. Moths without wings!”“Yes, my boy, moths without wings. You shall[376]see some. This one is called by learned men phalæna geometra, which means geometer-moth You will soon see why it is so named.”“But it has wings, magnificent ones, all dotted with brown spots on a yellowish background.”“Yes, and I will add that the forward ones have dark stripes. Now what do you think of this other moth?”“That ugly thing isn’t a moth.”“You judge by appearances, my dear child, and not by reality. This ungainly creature laboriously dragging along its big, naked, yellowish abdomen, with large black spots, is the female of the other moth.”“I should never have guessed it.”“Neither you nor a great many others. Henceforth you will know that there are numerous species of moths whose females are either wingless or equipped with such mere stumps of wings that they are unable to fly, whereas the males invariably have well-developed wings. Now, the male is not the one to be feared; it is the female with her eggs. The office of the tar girdle at the foot of the tree is to arrest the moth when it tries to climb to the branches where the laying takes place. Repulsed by the odor, it turns back; or if it persists in its endeavors to pass, it sticks to the tar and so perishes.”“If the female laid her eggs somewhere else,” suggested Jules, “instead of on the branches—for[377]instance, on the ground—wouldn’t the caterpillars know enough to climb the trees by themselves?”“The tar barrier would still be there to stop them. Besides, caterpillars hatched on the ground would hardly think of climbing the tree to the place where, in the usual order, the hatching would have taken place. As long as the customary conditions remain unaltered, insects show an astonishing instinct; beyond these conditions they do not know how to act.“The caterpillar of the geometer-moth is gray with a yellow stripe running lengthwise on each side. It has a curious way of walking common to it and other caterpillars of the same group.Linden InchwormLinden Inchworma, male moth;b, wingless female;c, larva, slightly enlarged.“These caterpillars are long and cylindrical in shape, and they usually have but two pairs of false legs, at some distance from the true front legs. In walking they first rest themselves on the forward legs and then bring up the others by curving the body into a loop or ring. The next movement is to raise the forward legs and advance them in a stride as long as the creature itself, after which the body again bends into a loop by the bringing up of[378]the hind legs as before. These peculiar strides give the worm the appearance of a pair of dividers getting over the ground by alternately opening and closing its two legs. You might say the creature surveys or measures the road it travels, and that is why its moth is known as the geometer-moth. The common name of inchworm applied to the caterpillar is familiar to you as referring to the caterpillar’s length.“Further characteristics are to be noted. Clinging to the branch solely by their hind creepers, these worms remain for hours in the strangest postures, the body stiff and motionless. You will see some stretched out straight, some turned up behind, some arched in a semicircular position. Not one moves, not one shows weariness in these uncomfortable attitudes which demand an incredible amount of strength. You have witnessed the feats of those strong-armed acrobats who, in the side-show at the fair, seize a vertical bar with both hands and without further support sustain themselves in the air, the body horizontal. Inchworms do the same thing, but with this difference: whereas the acrobats are exhausted in a few moments, the caterpillars keep their balance all day if necessary.”“Why do they do all those stunts?” was Emile’s question.“They are not doing stunts, as you call it; they are simply using their natural means of escaping observation on the part of their enemies. By reason of their complete immobility, rigid posture, and[379]grayish hue they are confounded with the small dry twigs which they closely resemble. Unless examined at very short range they deceive all eyes, even those of birds, whose sight is so keen.”“Ah, the crafty rogues! To stiffen themselves and stay perfectly still so as to look like little dry twigs and in that way fool the birds that would come and snap them up, is a very clever trick.”“The name of leaf-stripper, which is also given to this moth, indicates its way of living before it is transformed into the perfect insect. The caterpillar gnaws the leaves of all fruit-trees without distinction, and even of other trees, such as oaks, birches, and lindens. For trees that have not been smeared with a tar girdle to stop the moths at laying time there is but one mode of defense left, and that is not nearly so good as the first: it is to shake the infested trees so as to make the caterpillars fall, and then crush them.”“I prefer the tar girdle,” said Louis.“Yes, but it must be applied in time, in the autumn when the moths are about to make their appearance.“Another moth of this group, sometimes called the winter moth, has fore wings of a grayish wine-color dotted with brown and striped crosswise in a darker shade. The female is a little better favored than that of the one we have just been considering, having wings of a sort, but too rudimentary to admit of flying. It may be seen running over the ground toward the end of autumn, when cold[380]weather is approaching. Its tardy appearance has earned it the name of winter moth. Like the moth of the inchworm it climbs trees to lay its eggs, but can be prevented by the use of tar on the trunk. Its eggs hatch in the spring, and the caterpillars are full-grown by May. They are generally blackish, with white, yellow, or green stripes running lengthwise. On leaving the egg these caterpillars bore the buds of pear, apple, apricot, and other fruit trees. Later they install themselves, one by one, between two leaves, the edges of which they unite with threads of silk.”[381]
[Contents]CHAPTER LIITHE INCHWORMOne day Uncle Paul was in his garden engaged in an operation on his pear-trees that greatly puzzled Emile and Jules. He had a pot of black, sticky stuff with a strong smell, and was smearing it with a brush all around the base of the trees. Oh, how One-eyed John would have laughed if he had peeped through the hedge and seen Uncle Paul daubing the foot of his pear-trees with black! But he would have been greatly in the wrong, as is proved by what the boys’ uncle said to them that same evening.“What do you call that stuff you were putting on the trees this morning?” Jules inquired.“It is called tar, and is a substance derived from coal. To make illuminating gas coal is put into large cast-iron vessels and heated red-hot, all outside air being excluded meanwhile. The heat decomposes the coal, which cannot burn for want of air. The products of this decomposition are illuminating gas, tar, and coke, this last being a kind of coal of metallic appearance, very porous and light. The gas and the tar are drawn off through a pipe, the coke remaining in the cast-iron vessel. Tar is a very black, sticky substance with a strong odor repugnant to insects.”[375]“Then you put a coating of it around the tree trunks to keep off insects?”“Certain moths whose caterpillars I fear came through my hedge. The girdle of tar put on at the base of the trunk is to prevent their climbing to the branches to lay their eggs. In that way I protect the fruit-trees from the caterpillars that a little later would destroy the foliage.”“But moths can fly well enough, and your tar wouldn’t stop them. If they can’t reach the branches by climbing the trunk they will fly up to them.”“For a moth that flies, agreed. If on the contrary it cannot fly, but has to content itself with walking, is it not true that the coating of tar encircling the foot of the tree trunk will prove an impassable obstacle? In the first place, the smell of tar is offensive to the moth, and then if it ventures on the sticky girdle it will infallibly become entangled and die, stuck fast in the tar.”“That is plain,” assented Louis. “But are there any moths that can’t fly?”“There are.”“Are the lazy things afraid to use their wings?” asked Emile. “Perhaps they think it’s too much trouble.”“How could they use them? They haven’t any to use, poor things.”“That accounts for it, then. Moths without wings!”“Yes, my boy, moths without wings. You shall[376]see some. This one is called by learned men phalæna geometra, which means geometer-moth You will soon see why it is so named.”“But it has wings, magnificent ones, all dotted with brown spots on a yellowish background.”“Yes, and I will add that the forward ones have dark stripes. Now what do you think of this other moth?”“That ugly thing isn’t a moth.”“You judge by appearances, my dear child, and not by reality. This ungainly creature laboriously dragging along its big, naked, yellowish abdomen, with large black spots, is the female of the other moth.”“I should never have guessed it.”“Neither you nor a great many others. Henceforth you will know that there are numerous species of moths whose females are either wingless or equipped with such mere stumps of wings that they are unable to fly, whereas the males invariably have well-developed wings. Now, the male is not the one to be feared; it is the female with her eggs. The office of the tar girdle at the foot of the tree is to arrest the moth when it tries to climb to the branches where the laying takes place. Repulsed by the odor, it turns back; or if it persists in its endeavors to pass, it sticks to the tar and so perishes.”“If the female laid her eggs somewhere else,” suggested Jules, “instead of on the branches—for[377]instance, on the ground—wouldn’t the caterpillars know enough to climb the trees by themselves?”“The tar barrier would still be there to stop them. Besides, caterpillars hatched on the ground would hardly think of climbing the tree to the place where, in the usual order, the hatching would have taken place. As long as the customary conditions remain unaltered, insects show an astonishing instinct; beyond these conditions they do not know how to act.“The caterpillar of the geometer-moth is gray with a yellow stripe running lengthwise on each side. It has a curious way of walking common to it and other caterpillars of the same group.Linden InchwormLinden Inchworma, male moth;b, wingless female;c, larva, slightly enlarged.“These caterpillars are long and cylindrical in shape, and they usually have but two pairs of false legs, at some distance from the true front legs. In walking they first rest themselves on the forward legs and then bring up the others by curving the body into a loop or ring. The next movement is to raise the forward legs and advance them in a stride as long as the creature itself, after which the body again bends into a loop by the bringing up of[378]the hind legs as before. These peculiar strides give the worm the appearance of a pair of dividers getting over the ground by alternately opening and closing its two legs. You might say the creature surveys or measures the road it travels, and that is why its moth is known as the geometer-moth. The common name of inchworm applied to the caterpillar is familiar to you as referring to the caterpillar’s length.“Further characteristics are to be noted. Clinging to the branch solely by their hind creepers, these worms remain for hours in the strangest postures, the body stiff and motionless. You will see some stretched out straight, some turned up behind, some arched in a semicircular position. Not one moves, not one shows weariness in these uncomfortable attitudes which demand an incredible amount of strength. You have witnessed the feats of those strong-armed acrobats who, in the side-show at the fair, seize a vertical bar with both hands and without further support sustain themselves in the air, the body horizontal. Inchworms do the same thing, but with this difference: whereas the acrobats are exhausted in a few moments, the caterpillars keep their balance all day if necessary.”“Why do they do all those stunts?” was Emile’s question.“They are not doing stunts, as you call it; they are simply using their natural means of escaping observation on the part of their enemies. By reason of their complete immobility, rigid posture, and[379]grayish hue they are confounded with the small dry twigs which they closely resemble. Unless examined at very short range they deceive all eyes, even those of birds, whose sight is so keen.”“Ah, the crafty rogues! To stiffen themselves and stay perfectly still so as to look like little dry twigs and in that way fool the birds that would come and snap them up, is a very clever trick.”“The name of leaf-stripper, which is also given to this moth, indicates its way of living before it is transformed into the perfect insect. The caterpillar gnaws the leaves of all fruit-trees without distinction, and even of other trees, such as oaks, birches, and lindens. For trees that have not been smeared with a tar girdle to stop the moths at laying time there is but one mode of defense left, and that is not nearly so good as the first: it is to shake the infested trees so as to make the caterpillars fall, and then crush them.”“I prefer the tar girdle,” said Louis.“Yes, but it must be applied in time, in the autumn when the moths are about to make their appearance.“Another moth of this group, sometimes called the winter moth, has fore wings of a grayish wine-color dotted with brown and striped crosswise in a darker shade. The female is a little better favored than that of the one we have just been considering, having wings of a sort, but too rudimentary to admit of flying. It may be seen running over the ground toward the end of autumn, when cold[380]weather is approaching. Its tardy appearance has earned it the name of winter moth. Like the moth of the inchworm it climbs trees to lay its eggs, but can be prevented by the use of tar on the trunk. Its eggs hatch in the spring, and the caterpillars are full-grown by May. They are generally blackish, with white, yellow, or green stripes running lengthwise. On leaving the egg these caterpillars bore the buds of pear, apple, apricot, and other fruit trees. Later they install themselves, one by one, between two leaves, the edges of which they unite with threads of silk.”[381]
CHAPTER LIITHE INCHWORM
One day Uncle Paul was in his garden engaged in an operation on his pear-trees that greatly puzzled Emile and Jules. He had a pot of black, sticky stuff with a strong smell, and was smearing it with a brush all around the base of the trees. Oh, how One-eyed John would have laughed if he had peeped through the hedge and seen Uncle Paul daubing the foot of his pear-trees with black! But he would have been greatly in the wrong, as is proved by what the boys’ uncle said to them that same evening.“What do you call that stuff you were putting on the trees this morning?” Jules inquired.“It is called tar, and is a substance derived from coal. To make illuminating gas coal is put into large cast-iron vessels and heated red-hot, all outside air being excluded meanwhile. The heat decomposes the coal, which cannot burn for want of air. The products of this decomposition are illuminating gas, tar, and coke, this last being a kind of coal of metallic appearance, very porous and light. The gas and the tar are drawn off through a pipe, the coke remaining in the cast-iron vessel. Tar is a very black, sticky substance with a strong odor repugnant to insects.”[375]“Then you put a coating of it around the tree trunks to keep off insects?”“Certain moths whose caterpillars I fear came through my hedge. The girdle of tar put on at the base of the trunk is to prevent their climbing to the branches to lay their eggs. In that way I protect the fruit-trees from the caterpillars that a little later would destroy the foliage.”“But moths can fly well enough, and your tar wouldn’t stop them. If they can’t reach the branches by climbing the trunk they will fly up to them.”“For a moth that flies, agreed. If on the contrary it cannot fly, but has to content itself with walking, is it not true that the coating of tar encircling the foot of the tree trunk will prove an impassable obstacle? In the first place, the smell of tar is offensive to the moth, and then if it ventures on the sticky girdle it will infallibly become entangled and die, stuck fast in the tar.”“That is plain,” assented Louis. “But are there any moths that can’t fly?”“There are.”“Are the lazy things afraid to use their wings?” asked Emile. “Perhaps they think it’s too much trouble.”“How could they use them? They haven’t any to use, poor things.”“That accounts for it, then. Moths without wings!”“Yes, my boy, moths without wings. You shall[376]see some. This one is called by learned men phalæna geometra, which means geometer-moth You will soon see why it is so named.”“But it has wings, magnificent ones, all dotted with brown spots on a yellowish background.”“Yes, and I will add that the forward ones have dark stripes. Now what do you think of this other moth?”“That ugly thing isn’t a moth.”“You judge by appearances, my dear child, and not by reality. This ungainly creature laboriously dragging along its big, naked, yellowish abdomen, with large black spots, is the female of the other moth.”“I should never have guessed it.”“Neither you nor a great many others. Henceforth you will know that there are numerous species of moths whose females are either wingless or equipped with such mere stumps of wings that they are unable to fly, whereas the males invariably have well-developed wings. Now, the male is not the one to be feared; it is the female with her eggs. The office of the tar girdle at the foot of the tree is to arrest the moth when it tries to climb to the branches where the laying takes place. Repulsed by the odor, it turns back; or if it persists in its endeavors to pass, it sticks to the tar and so perishes.”“If the female laid her eggs somewhere else,” suggested Jules, “instead of on the branches—for[377]instance, on the ground—wouldn’t the caterpillars know enough to climb the trees by themselves?”“The tar barrier would still be there to stop them. Besides, caterpillars hatched on the ground would hardly think of climbing the tree to the place where, in the usual order, the hatching would have taken place. As long as the customary conditions remain unaltered, insects show an astonishing instinct; beyond these conditions they do not know how to act.“The caterpillar of the geometer-moth is gray with a yellow stripe running lengthwise on each side. It has a curious way of walking common to it and other caterpillars of the same group.Linden InchwormLinden Inchworma, male moth;b, wingless female;c, larva, slightly enlarged.“These caterpillars are long and cylindrical in shape, and they usually have but two pairs of false legs, at some distance from the true front legs. In walking they first rest themselves on the forward legs and then bring up the others by curving the body into a loop or ring. The next movement is to raise the forward legs and advance them in a stride as long as the creature itself, after which the body again bends into a loop by the bringing up of[378]the hind legs as before. These peculiar strides give the worm the appearance of a pair of dividers getting over the ground by alternately opening and closing its two legs. You might say the creature surveys or measures the road it travels, and that is why its moth is known as the geometer-moth. The common name of inchworm applied to the caterpillar is familiar to you as referring to the caterpillar’s length.“Further characteristics are to be noted. Clinging to the branch solely by their hind creepers, these worms remain for hours in the strangest postures, the body stiff and motionless. You will see some stretched out straight, some turned up behind, some arched in a semicircular position. Not one moves, not one shows weariness in these uncomfortable attitudes which demand an incredible amount of strength. You have witnessed the feats of those strong-armed acrobats who, in the side-show at the fair, seize a vertical bar with both hands and without further support sustain themselves in the air, the body horizontal. Inchworms do the same thing, but with this difference: whereas the acrobats are exhausted in a few moments, the caterpillars keep their balance all day if necessary.”“Why do they do all those stunts?” was Emile’s question.“They are not doing stunts, as you call it; they are simply using their natural means of escaping observation on the part of their enemies. By reason of their complete immobility, rigid posture, and[379]grayish hue they are confounded with the small dry twigs which they closely resemble. Unless examined at very short range they deceive all eyes, even those of birds, whose sight is so keen.”“Ah, the crafty rogues! To stiffen themselves and stay perfectly still so as to look like little dry twigs and in that way fool the birds that would come and snap them up, is a very clever trick.”“The name of leaf-stripper, which is also given to this moth, indicates its way of living before it is transformed into the perfect insect. The caterpillar gnaws the leaves of all fruit-trees without distinction, and even of other trees, such as oaks, birches, and lindens. For trees that have not been smeared with a tar girdle to stop the moths at laying time there is but one mode of defense left, and that is not nearly so good as the first: it is to shake the infested trees so as to make the caterpillars fall, and then crush them.”“I prefer the tar girdle,” said Louis.“Yes, but it must be applied in time, in the autumn when the moths are about to make their appearance.“Another moth of this group, sometimes called the winter moth, has fore wings of a grayish wine-color dotted with brown and striped crosswise in a darker shade. The female is a little better favored than that of the one we have just been considering, having wings of a sort, but too rudimentary to admit of flying. It may be seen running over the ground toward the end of autumn, when cold[380]weather is approaching. Its tardy appearance has earned it the name of winter moth. Like the moth of the inchworm it climbs trees to lay its eggs, but can be prevented by the use of tar on the trunk. Its eggs hatch in the spring, and the caterpillars are full-grown by May. They are generally blackish, with white, yellow, or green stripes running lengthwise. On leaving the egg these caterpillars bore the buds of pear, apple, apricot, and other fruit trees. Later they install themselves, one by one, between two leaves, the edges of which they unite with threads of silk.”[381]
One day Uncle Paul was in his garden engaged in an operation on his pear-trees that greatly puzzled Emile and Jules. He had a pot of black, sticky stuff with a strong smell, and was smearing it with a brush all around the base of the trees. Oh, how One-eyed John would have laughed if he had peeped through the hedge and seen Uncle Paul daubing the foot of his pear-trees with black! But he would have been greatly in the wrong, as is proved by what the boys’ uncle said to them that same evening.
“What do you call that stuff you were putting on the trees this morning?” Jules inquired.
“It is called tar, and is a substance derived from coal. To make illuminating gas coal is put into large cast-iron vessels and heated red-hot, all outside air being excluded meanwhile. The heat decomposes the coal, which cannot burn for want of air. The products of this decomposition are illuminating gas, tar, and coke, this last being a kind of coal of metallic appearance, very porous and light. The gas and the tar are drawn off through a pipe, the coke remaining in the cast-iron vessel. Tar is a very black, sticky substance with a strong odor repugnant to insects.”[375]
“Then you put a coating of it around the tree trunks to keep off insects?”
“Certain moths whose caterpillars I fear came through my hedge. The girdle of tar put on at the base of the trunk is to prevent their climbing to the branches to lay their eggs. In that way I protect the fruit-trees from the caterpillars that a little later would destroy the foliage.”
“But moths can fly well enough, and your tar wouldn’t stop them. If they can’t reach the branches by climbing the trunk they will fly up to them.”
“For a moth that flies, agreed. If on the contrary it cannot fly, but has to content itself with walking, is it not true that the coating of tar encircling the foot of the tree trunk will prove an impassable obstacle? In the first place, the smell of tar is offensive to the moth, and then if it ventures on the sticky girdle it will infallibly become entangled and die, stuck fast in the tar.”
“That is plain,” assented Louis. “But are there any moths that can’t fly?”
“There are.”
“Are the lazy things afraid to use their wings?” asked Emile. “Perhaps they think it’s too much trouble.”
“How could they use them? They haven’t any to use, poor things.”
“That accounts for it, then. Moths without wings!”
“Yes, my boy, moths without wings. You shall[376]see some. This one is called by learned men phalæna geometra, which means geometer-moth You will soon see why it is so named.”
“But it has wings, magnificent ones, all dotted with brown spots on a yellowish background.”
“Yes, and I will add that the forward ones have dark stripes. Now what do you think of this other moth?”
“That ugly thing isn’t a moth.”
“You judge by appearances, my dear child, and not by reality. This ungainly creature laboriously dragging along its big, naked, yellowish abdomen, with large black spots, is the female of the other moth.”
“I should never have guessed it.”
“Neither you nor a great many others. Henceforth you will know that there are numerous species of moths whose females are either wingless or equipped with such mere stumps of wings that they are unable to fly, whereas the males invariably have well-developed wings. Now, the male is not the one to be feared; it is the female with her eggs. The office of the tar girdle at the foot of the tree is to arrest the moth when it tries to climb to the branches where the laying takes place. Repulsed by the odor, it turns back; or if it persists in its endeavors to pass, it sticks to the tar and so perishes.”
“If the female laid her eggs somewhere else,” suggested Jules, “instead of on the branches—for[377]instance, on the ground—wouldn’t the caterpillars know enough to climb the trees by themselves?”
“The tar barrier would still be there to stop them. Besides, caterpillars hatched on the ground would hardly think of climbing the tree to the place where, in the usual order, the hatching would have taken place. As long as the customary conditions remain unaltered, insects show an astonishing instinct; beyond these conditions they do not know how to act.
“The caterpillar of the geometer-moth is gray with a yellow stripe running lengthwise on each side. It has a curious way of walking common to it and other caterpillars of the same group.
Linden InchwormLinden Inchworma, male moth;b, wingless female;c, larva, slightly enlarged.
Linden Inchworm
a, male moth;b, wingless female;c, larva, slightly enlarged.
“These caterpillars are long and cylindrical in shape, and they usually have but two pairs of false legs, at some distance from the true front legs. In walking they first rest themselves on the forward legs and then bring up the others by curving the body into a loop or ring. The next movement is to raise the forward legs and advance them in a stride as long as the creature itself, after which the body again bends into a loop by the bringing up of[378]the hind legs as before. These peculiar strides give the worm the appearance of a pair of dividers getting over the ground by alternately opening and closing its two legs. You might say the creature surveys or measures the road it travels, and that is why its moth is known as the geometer-moth. The common name of inchworm applied to the caterpillar is familiar to you as referring to the caterpillar’s length.
“Further characteristics are to be noted. Clinging to the branch solely by their hind creepers, these worms remain for hours in the strangest postures, the body stiff and motionless. You will see some stretched out straight, some turned up behind, some arched in a semicircular position. Not one moves, not one shows weariness in these uncomfortable attitudes which demand an incredible amount of strength. You have witnessed the feats of those strong-armed acrobats who, in the side-show at the fair, seize a vertical bar with both hands and without further support sustain themselves in the air, the body horizontal. Inchworms do the same thing, but with this difference: whereas the acrobats are exhausted in a few moments, the caterpillars keep their balance all day if necessary.”
“Why do they do all those stunts?” was Emile’s question.
“They are not doing stunts, as you call it; they are simply using their natural means of escaping observation on the part of their enemies. By reason of their complete immobility, rigid posture, and[379]grayish hue they are confounded with the small dry twigs which they closely resemble. Unless examined at very short range they deceive all eyes, even those of birds, whose sight is so keen.”
“Ah, the crafty rogues! To stiffen themselves and stay perfectly still so as to look like little dry twigs and in that way fool the birds that would come and snap them up, is a very clever trick.”
“The name of leaf-stripper, which is also given to this moth, indicates its way of living before it is transformed into the perfect insect. The caterpillar gnaws the leaves of all fruit-trees without distinction, and even of other trees, such as oaks, birches, and lindens. For trees that have not been smeared with a tar girdle to stop the moths at laying time there is but one mode of defense left, and that is not nearly so good as the first: it is to shake the infested trees so as to make the caterpillars fall, and then crush them.”
“I prefer the tar girdle,” said Louis.
“Yes, but it must be applied in time, in the autumn when the moths are about to make their appearance.
“Another moth of this group, sometimes called the winter moth, has fore wings of a grayish wine-color dotted with brown and striped crosswise in a darker shade. The female is a little better favored than that of the one we have just been considering, having wings of a sort, but too rudimentary to admit of flying. It may be seen running over the ground toward the end of autumn, when cold[380]weather is approaching. Its tardy appearance has earned it the name of winter moth. Like the moth of the inchworm it climbs trees to lay its eggs, but can be prevented by the use of tar on the trunk. Its eggs hatch in the spring, and the caterpillars are full-grown by May. They are generally blackish, with white, yellow, or green stripes running lengthwise. On leaving the egg these caterpillars bore the buds of pear, apple, apricot, and other fruit trees. Later they install themselves, one by one, between two leaves, the edges of which they unite with threads of silk.”[381]