[Contents]CHAPTER XXXVIIITHE GRAIN-WEEVILUncle Paul had sent old Jacques to town to buy the drug they were going to apply to Simon’s wheat. Meanwhile he took occasion to tell his young hearers about the wheat-devourer that was to have the benefit of the drug. The handful of grain left by Simon was in a plate on the table. The little weevils were running about in frantic endeavors to escape, while Emile with a straw was pushing them back into the middle of the plate, where they cowered among the kernels of wheat. Louis and Jules were also there, all attention to what was going on.Grain-weevilsGrain-weevilsa, corn-weevil;b, rice-weevil;c, larva;d, pupa.“This ravager of our granaries,” began Uncle Paul, “is called the grain-weevil, or, in Latin,calandra. It belongs to the order of coleoptera or beetles. Its defensive armor is a hard brown casing finely engraved. It has no membranous wings under the elytra or wing sheaths. Hence it is unable[296]to fly, but it runs fast enough and it clings to objects with a firm grip. You see how busy Emile is kept with his straw in preventing the prisoners’ escape. The grain-weevil is about four millimeters long, its body is of a uniform blackish brown, and its head ends in a long snout, a kind of slender trumpet. The corselet or thorax is long, marked with fine pricks or dots, and the wing sheaths are delicately furrowed. The insect’s most striking characteristic is its long, trumpet-shaped snout.”“It seems to me,” said Jules, “I have seen other beetles, and rather large ones, too, with the head ending in a trumpet like that.”“I’ve found them on hazels,” added Louis, “and they had a long, slender beak that would make you think the insect was smoking a long pipe.”“The trumpet beetles form a numerous class, and they are all weevils, but their mode of life varies for the different species. Some attack fruit-trees and grape-vines. We will speak of them one of these days.“With its pointed snout the grain-weevil makes a tiny hole in a kernel of wheat, and in this it lays an egg which it makes fast by means of a sticky liquid from its own body. Then it passes immediately to other kernels and treats them in the same way, until its store of eggs is exhausted. And all this is done with such delicate nicety that the sharpest eyes would fail to detect any trace of these mischievous germs in the kernels. But a weevil knows very well when a kernel has already received an[297]egg, from whatever source, and never does it commit the blunder of laying a second one there, for the grain of wheat is too small for more than one eater. To each kernel its larva, to each larva its kernel, and no more.“Soon the eggs hatch. The tiny worm punctures the envelop of the grain and through the almost invisible opening makes its way into the mealy substance within. There it is at home, in perfect quiet, peacefully devoted to the pleasures of feasting. For its own exclusive use a grain of wheat, a whole grain of wheat! Thus it grows big and fat. In five or six weeks the flour is all eaten up, but the bran remains, for the clever larva is careful not to make a hole in it; it will need it to serve as a cradle during the coming change. The gnawed kernel appears quite whole, when as a matter of fact it is hollow and lodges a weevil. In this hiding-place the larva turns into a nymph, and the latter into a perfect insect. Then the fully developed weevil tears open the bran covering and leaves its home to explore the pile of wheat, select certain ungnawed grains, and lay its eggs in them, eggs that will in time produce a new population of ravagers.”Here Uncle Paul picked out a few grains, one by one, and submitted them to his hearers’ scrutiny.“What do you see that is at all unusual in those grains?” he asked. “Look at them well.”“I have looked and looked,” Emile replied after a little, “and I don’t see anything.”“I don’t see anything, either,” said Jules.[298]“Nor I,” added Louis.“Those grains, boys, have no flour in them, despite their fair outside appearance; the weevil has emptied them.”“But how can you tell so easily?” asked Jules.“A kernel inhabited by the grain-weevil yields to the pressure of a finger and is also lighter in weight than one that is sound. From appearance alone one cannot tell infested kernels from uninjured ones, as the outside looks the same in both cases. Thus, without extreme vigilance, the inroads of the weevil pass unperceived until the developed insects show themselves; and then the evil is beyond remedy. Didn’t Simon think he had a fine lot of wheat when there was hardly anything but the bran left? A very simple experiment suffices to prove the condition of the wheat. Throw a handful of it into water and all the sound kernels will sink to the bottom, all the unsound ones float on the surface. We will perform this experiment with the wheat on the plate if Jules will go to the spring and bring a glass of water.”The water was brought and Uncle Paul threw the wheat into it. A few grains sank, many floated. These latter were opened with the point of a pin, and in some was found a little soft white worm, without legs, but furnished with strong mandibles. It was the larva of the grain-weevil. In others there was a white nymph, and in a few was the perfect insect all ready to leave its snug abode.“To judge by the number of grains that floated,”[299]Jules remarked, “Simon’s pile of wheat, even if it is not a very big one, must contain millions of weevils. It must have taken a lot of the creatures to produce such an immense family, mustn’t it?”“Not so many as you might think. How many eggs do you suppose one weevil lays?”“A dozen, perhaps.”“Ah, how far out you are in your reckoning! In the course of one season a weevil lays from eight to ten thousand eggs, from which spring as many larvæ, each gnawing a grain. A liter measure1contains, on an average, ten thousand grains of wheat. To feed the family of one weevil, therefore, nearly a liter of wheat is needed. Suppose there are a thousand pairs of these insects in a granary; that would be enough to destroy ten hectoliters of wheat, rye, barley, or oats; for they attack all kinds of grain impartially.”[300]1A liter is slightly more than a quart, a hectoliter a little more than one hundred quarts.—Translator.↑
[Contents]CHAPTER XXXVIIITHE GRAIN-WEEVILUncle Paul had sent old Jacques to town to buy the drug they were going to apply to Simon’s wheat. Meanwhile he took occasion to tell his young hearers about the wheat-devourer that was to have the benefit of the drug. The handful of grain left by Simon was in a plate on the table. The little weevils were running about in frantic endeavors to escape, while Emile with a straw was pushing them back into the middle of the plate, where they cowered among the kernels of wheat. Louis and Jules were also there, all attention to what was going on.Grain-weevilsGrain-weevilsa, corn-weevil;b, rice-weevil;c, larva;d, pupa.“This ravager of our granaries,” began Uncle Paul, “is called the grain-weevil, or, in Latin,calandra. It belongs to the order of coleoptera or beetles. Its defensive armor is a hard brown casing finely engraved. It has no membranous wings under the elytra or wing sheaths. Hence it is unable[296]to fly, but it runs fast enough and it clings to objects with a firm grip. You see how busy Emile is kept with his straw in preventing the prisoners’ escape. The grain-weevil is about four millimeters long, its body is of a uniform blackish brown, and its head ends in a long snout, a kind of slender trumpet. The corselet or thorax is long, marked with fine pricks or dots, and the wing sheaths are delicately furrowed. The insect’s most striking characteristic is its long, trumpet-shaped snout.”“It seems to me,” said Jules, “I have seen other beetles, and rather large ones, too, with the head ending in a trumpet like that.”“I’ve found them on hazels,” added Louis, “and they had a long, slender beak that would make you think the insect was smoking a long pipe.”“The trumpet beetles form a numerous class, and they are all weevils, but their mode of life varies for the different species. Some attack fruit-trees and grape-vines. We will speak of them one of these days.“With its pointed snout the grain-weevil makes a tiny hole in a kernel of wheat, and in this it lays an egg which it makes fast by means of a sticky liquid from its own body. Then it passes immediately to other kernels and treats them in the same way, until its store of eggs is exhausted. And all this is done with such delicate nicety that the sharpest eyes would fail to detect any trace of these mischievous germs in the kernels. But a weevil knows very well when a kernel has already received an[297]egg, from whatever source, and never does it commit the blunder of laying a second one there, for the grain of wheat is too small for more than one eater. To each kernel its larva, to each larva its kernel, and no more.“Soon the eggs hatch. The tiny worm punctures the envelop of the grain and through the almost invisible opening makes its way into the mealy substance within. There it is at home, in perfect quiet, peacefully devoted to the pleasures of feasting. For its own exclusive use a grain of wheat, a whole grain of wheat! Thus it grows big and fat. In five or six weeks the flour is all eaten up, but the bran remains, for the clever larva is careful not to make a hole in it; it will need it to serve as a cradle during the coming change. The gnawed kernel appears quite whole, when as a matter of fact it is hollow and lodges a weevil. In this hiding-place the larva turns into a nymph, and the latter into a perfect insect. Then the fully developed weevil tears open the bran covering and leaves its home to explore the pile of wheat, select certain ungnawed grains, and lay its eggs in them, eggs that will in time produce a new population of ravagers.”Here Uncle Paul picked out a few grains, one by one, and submitted them to his hearers’ scrutiny.“What do you see that is at all unusual in those grains?” he asked. “Look at them well.”“I have looked and looked,” Emile replied after a little, “and I don’t see anything.”“I don’t see anything, either,” said Jules.[298]“Nor I,” added Louis.“Those grains, boys, have no flour in them, despite their fair outside appearance; the weevil has emptied them.”“But how can you tell so easily?” asked Jules.“A kernel inhabited by the grain-weevil yields to the pressure of a finger and is also lighter in weight than one that is sound. From appearance alone one cannot tell infested kernels from uninjured ones, as the outside looks the same in both cases. Thus, without extreme vigilance, the inroads of the weevil pass unperceived until the developed insects show themselves; and then the evil is beyond remedy. Didn’t Simon think he had a fine lot of wheat when there was hardly anything but the bran left? A very simple experiment suffices to prove the condition of the wheat. Throw a handful of it into water and all the sound kernels will sink to the bottom, all the unsound ones float on the surface. We will perform this experiment with the wheat on the plate if Jules will go to the spring and bring a glass of water.”The water was brought and Uncle Paul threw the wheat into it. A few grains sank, many floated. These latter were opened with the point of a pin, and in some was found a little soft white worm, without legs, but furnished with strong mandibles. It was the larva of the grain-weevil. In others there was a white nymph, and in a few was the perfect insect all ready to leave its snug abode.“To judge by the number of grains that floated,”[299]Jules remarked, “Simon’s pile of wheat, even if it is not a very big one, must contain millions of weevils. It must have taken a lot of the creatures to produce such an immense family, mustn’t it?”“Not so many as you might think. How many eggs do you suppose one weevil lays?”“A dozen, perhaps.”“Ah, how far out you are in your reckoning! In the course of one season a weevil lays from eight to ten thousand eggs, from which spring as many larvæ, each gnawing a grain. A liter measure1contains, on an average, ten thousand grains of wheat. To feed the family of one weevil, therefore, nearly a liter of wheat is needed. Suppose there are a thousand pairs of these insects in a granary; that would be enough to destroy ten hectoliters of wheat, rye, barley, or oats; for they attack all kinds of grain impartially.”[300]1A liter is slightly more than a quart, a hectoliter a little more than one hundred quarts.—Translator.↑
CHAPTER XXXVIIITHE GRAIN-WEEVIL
Uncle Paul had sent old Jacques to town to buy the drug they were going to apply to Simon’s wheat. Meanwhile he took occasion to tell his young hearers about the wheat-devourer that was to have the benefit of the drug. The handful of grain left by Simon was in a plate on the table. The little weevils were running about in frantic endeavors to escape, while Emile with a straw was pushing them back into the middle of the plate, where they cowered among the kernels of wheat. Louis and Jules were also there, all attention to what was going on.Grain-weevilsGrain-weevilsa, corn-weevil;b, rice-weevil;c, larva;d, pupa.“This ravager of our granaries,” began Uncle Paul, “is called the grain-weevil, or, in Latin,calandra. It belongs to the order of coleoptera or beetles. Its defensive armor is a hard brown casing finely engraved. It has no membranous wings under the elytra or wing sheaths. Hence it is unable[296]to fly, but it runs fast enough and it clings to objects with a firm grip. You see how busy Emile is kept with his straw in preventing the prisoners’ escape. The grain-weevil is about four millimeters long, its body is of a uniform blackish brown, and its head ends in a long snout, a kind of slender trumpet. The corselet or thorax is long, marked with fine pricks or dots, and the wing sheaths are delicately furrowed. The insect’s most striking characteristic is its long, trumpet-shaped snout.”“It seems to me,” said Jules, “I have seen other beetles, and rather large ones, too, with the head ending in a trumpet like that.”“I’ve found them on hazels,” added Louis, “and they had a long, slender beak that would make you think the insect was smoking a long pipe.”“The trumpet beetles form a numerous class, and they are all weevils, but their mode of life varies for the different species. Some attack fruit-trees and grape-vines. We will speak of them one of these days.“With its pointed snout the grain-weevil makes a tiny hole in a kernel of wheat, and in this it lays an egg which it makes fast by means of a sticky liquid from its own body. Then it passes immediately to other kernels and treats them in the same way, until its store of eggs is exhausted. And all this is done with such delicate nicety that the sharpest eyes would fail to detect any trace of these mischievous germs in the kernels. But a weevil knows very well when a kernel has already received an[297]egg, from whatever source, and never does it commit the blunder of laying a second one there, for the grain of wheat is too small for more than one eater. To each kernel its larva, to each larva its kernel, and no more.“Soon the eggs hatch. The tiny worm punctures the envelop of the grain and through the almost invisible opening makes its way into the mealy substance within. There it is at home, in perfect quiet, peacefully devoted to the pleasures of feasting. For its own exclusive use a grain of wheat, a whole grain of wheat! Thus it grows big and fat. In five or six weeks the flour is all eaten up, but the bran remains, for the clever larva is careful not to make a hole in it; it will need it to serve as a cradle during the coming change. The gnawed kernel appears quite whole, when as a matter of fact it is hollow and lodges a weevil. In this hiding-place the larva turns into a nymph, and the latter into a perfect insect. Then the fully developed weevil tears open the bran covering and leaves its home to explore the pile of wheat, select certain ungnawed grains, and lay its eggs in them, eggs that will in time produce a new population of ravagers.”Here Uncle Paul picked out a few grains, one by one, and submitted them to his hearers’ scrutiny.“What do you see that is at all unusual in those grains?” he asked. “Look at them well.”“I have looked and looked,” Emile replied after a little, “and I don’t see anything.”“I don’t see anything, either,” said Jules.[298]“Nor I,” added Louis.“Those grains, boys, have no flour in them, despite their fair outside appearance; the weevil has emptied them.”“But how can you tell so easily?” asked Jules.“A kernel inhabited by the grain-weevil yields to the pressure of a finger and is also lighter in weight than one that is sound. From appearance alone one cannot tell infested kernels from uninjured ones, as the outside looks the same in both cases. Thus, without extreme vigilance, the inroads of the weevil pass unperceived until the developed insects show themselves; and then the evil is beyond remedy. Didn’t Simon think he had a fine lot of wheat when there was hardly anything but the bran left? A very simple experiment suffices to prove the condition of the wheat. Throw a handful of it into water and all the sound kernels will sink to the bottom, all the unsound ones float on the surface. We will perform this experiment with the wheat on the plate if Jules will go to the spring and bring a glass of water.”The water was brought and Uncle Paul threw the wheat into it. A few grains sank, many floated. These latter were opened with the point of a pin, and in some was found a little soft white worm, without legs, but furnished with strong mandibles. It was the larva of the grain-weevil. In others there was a white nymph, and in a few was the perfect insect all ready to leave its snug abode.“To judge by the number of grains that floated,”[299]Jules remarked, “Simon’s pile of wheat, even if it is not a very big one, must contain millions of weevils. It must have taken a lot of the creatures to produce such an immense family, mustn’t it?”“Not so many as you might think. How many eggs do you suppose one weevil lays?”“A dozen, perhaps.”“Ah, how far out you are in your reckoning! In the course of one season a weevil lays from eight to ten thousand eggs, from which spring as many larvæ, each gnawing a grain. A liter measure1contains, on an average, ten thousand grains of wheat. To feed the family of one weevil, therefore, nearly a liter of wheat is needed. Suppose there are a thousand pairs of these insects in a granary; that would be enough to destroy ten hectoliters of wheat, rye, barley, or oats; for they attack all kinds of grain impartially.”[300]
Uncle Paul had sent old Jacques to town to buy the drug they were going to apply to Simon’s wheat. Meanwhile he took occasion to tell his young hearers about the wheat-devourer that was to have the benefit of the drug. The handful of grain left by Simon was in a plate on the table. The little weevils were running about in frantic endeavors to escape, while Emile with a straw was pushing them back into the middle of the plate, where they cowered among the kernels of wheat. Louis and Jules were also there, all attention to what was going on.
Grain-weevilsGrain-weevilsa, corn-weevil;b, rice-weevil;c, larva;d, pupa.
Grain-weevils
a, corn-weevil;b, rice-weevil;c, larva;d, pupa.
“This ravager of our granaries,” began Uncle Paul, “is called the grain-weevil, or, in Latin,calandra. It belongs to the order of coleoptera or beetles. Its defensive armor is a hard brown casing finely engraved. It has no membranous wings under the elytra or wing sheaths. Hence it is unable[296]to fly, but it runs fast enough and it clings to objects with a firm grip. You see how busy Emile is kept with his straw in preventing the prisoners’ escape. The grain-weevil is about four millimeters long, its body is of a uniform blackish brown, and its head ends in a long snout, a kind of slender trumpet. The corselet or thorax is long, marked with fine pricks or dots, and the wing sheaths are delicately furrowed. The insect’s most striking characteristic is its long, trumpet-shaped snout.”
“It seems to me,” said Jules, “I have seen other beetles, and rather large ones, too, with the head ending in a trumpet like that.”
“I’ve found them on hazels,” added Louis, “and they had a long, slender beak that would make you think the insect was smoking a long pipe.”
“The trumpet beetles form a numerous class, and they are all weevils, but their mode of life varies for the different species. Some attack fruit-trees and grape-vines. We will speak of them one of these days.
“With its pointed snout the grain-weevil makes a tiny hole in a kernel of wheat, and in this it lays an egg which it makes fast by means of a sticky liquid from its own body. Then it passes immediately to other kernels and treats them in the same way, until its store of eggs is exhausted. And all this is done with such delicate nicety that the sharpest eyes would fail to detect any trace of these mischievous germs in the kernels. But a weevil knows very well when a kernel has already received an[297]egg, from whatever source, and never does it commit the blunder of laying a second one there, for the grain of wheat is too small for more than one eater. To each kernel its larva, to each larva its kernel, and no more.
“Soon the eggs hatch. The tiny worm punctures the envelop of the grain and through the almost invisible opening makes its way into the mealy substance within. There it is at home, in perfect quiet, peacefully devoted to the pleasures of feasting. For its own exclusive use a grain of wheat, a whole grain of wheat! Thus it grows big and fat. In five or six weeks the flour is all eaten up, but the bran remains, for the clever larva is careful not to make a hole in it; it will need it to serve as a cradle during the coming change. The gnawed kernel appears quite whole, when as a matter of fact it is hollow and lodges a weevil. In this hiding-place the larva turns into a nymph, and the latter into a perfect insect. Then the fully developed weevil tears open the bran covering and leaves its home to explore the pile of wheat, select certain ungnawed grains, and lay its eggs in them, eggs that will in time produce a new population of ravagers.”
Here Uncle Paul picked out a few grains, one by one, and submitted them to his hearers’ scrutiny.
“What do you see that is at all unusual in those grains?” he asked. “Look at them well.”
“I have looked and looked,” Emile replied after a little, “and I don’t see anything.”
“I don’t see anything, either,” said Jules.[298]
“Nor I,” added Louis.
“Those grains, boys, have no flour in them, despite their fair outside appearance; the weevil has emptied them.”
“But how can you tell so easily?” asked Jules.
“A kernel inhabited by the grain-weevil yields to the pressure of a finger and is also lighter in weight than one that is sound. From appearance alone one cannot tell infested kernels from uninjured ones, as the outside looks the same in both cases. Thus, without extreme vigilance, the inroads of the weevil pass unperceived until the developed insects show themselves; and then the evil is beyond remedy. Didn’t Simon think he had a fine lot of wheat when there was hardly anything but the bran left? A very simple experiment suffices to prove the condition of the wheat. Throw a handful of it into water and all the sound kernels will sink to the bottom, all the unsound ones float on the surface. We will perform this experiment with the wheat on the plate if Jules will go to the spring and bring a glass of water.”
The water was brought and Uncle Paul threw the wheat into it. A few grains sank, many floated. These latter were opened with the point of a pin, and in some was found a little soft white worm, without legs, but furnished with strong mandibles. It was the larva of the grain-weevil. In others there was a white nymph, and in a few was the perfect insect all ready to leave its snug abode.
“To judge by the number of grains that floated,”[299]Jules remarked, “Simon’s pile of wheat, even if it is not a very big one, must contain millions of weevils. It must have taken a lot of the creatures to produce such an immense family, mustn’t it?”
“Not so many as you might think. How many eggs do you suppose one weevil lays?”
“A dozen, perhaps.”
“Ah, how far out you are in your reckoning! In the course of one season a weevil lays from eight to ten thousand eggs, from which spring as many larvæ, each gnawing a grain. A liter measure1contains, on an average, ten thousand grains of wheat. To feed the family of one weevil, therefore, nearly a liter of wheat is needed. Suppose there are a thousand pairs of these insects in a granary; that would be enough to destroy ten hectoliters of wheat, rye, barley, or oats; for they attack all kinds of grain impartially.”[300]
1A liter is slightly more than a quart, a hectoliter a little more than one hundred quarts.—Translator.↑
1A liter is slightly more than a quart, a hectoliter a little more than one hundred quarts.—Translator.↑
1A liter is slightly more than a quart, a hectoliter a little more than one hundred quarts.—Translator.↑
1A liter is slightly more than a quart, a hectoliter a little more than one hundred quarts.—Translator.↑