THE PUSS-MOTH—CURIOUS CATERPILLAR—A STRONG FORTRESS—THE BURNET-MOTH—OAK EGGER—HOW TO KILL INSECTS—TWOFOLD LIFE—VICTIMS OF LOVE—ACUTE SENSES—THE STORY OF INSECT LIFE—DRINKER MOTH—CATERPILLAR BOX—EMPEROR MOTH—TYPE OF THE MOUSE-TRAP.
THE PUSS-MOTH—CURIOUS CATERPILLAR—A STRONG FORTRESS—THE BURNET-MOTH—OAK EGGER—HOW TO KILL INSECTS—TWOFOLD LIFE—VICTIMS OF LOVE—ACUTE SENSES—THE STORY OF INSECT LIFE—DRINKER MOTH—CATERPILLAR BOX—EMPEROR MOTH—TYPE OF THE MOUSE-TRAP.
Just at the right hand of the Tiger-moth, onplate B, may be seen a caterpillar of a very strange and eccentric form, and marked by the number 4a. This is the larva or caterpillar of the Puss-moth, and is no less beautiful in colouring than fantastic in form. Its attitude, too, when it is at rest, is quite as curious as its general appearance.
While eating, it sits on the leaves and twigs much as any other caterpillar; but when it ceases to feed, and reposes itself, it grasps the twig firmly with the claspers with which the hinder portion of its body is furnished, and raises the fore-part of its body half upright. In this attitude it much resembles that of the Egyptian Sphinx, and from this circumstance the moth itself is called a Sphinx. An old gardener was once quite put out of temper by seeing several of these caterpillars for the first time, because they had so consequential an air.
The colouring of this creature varies according to the time of year; but it may be easily recognised by its form alone, which is very peculiar.
One of the most remarkable points in the creature is the forked apparatus at the end of the tail, and which frightens people who do not know the habits of the caterpillar. These forks are black externally, and rather stiff, but are only sheaths for two curious rose-coloured tentacles, which are usually kept hidden, but which may be seen by touching the caterpillar with the point of a needle. When the creature is thus irritated, it will protrude these tentacles from their sheath, and will then strike the part that had been touched.
It is supposed that this apparatus is intended as a kind of whip, wherewith to drive away the ichneumon flies, and other parasites, that inflict such annoyance on many caterpillars.
When this caterpillar proceeds to its pupal state, it makes itself a wonderful fortress—not suspended like that of the Tiger-moth, nor hidden in a dark spot; but it boldly fixes its residence on the exterior of the tree on which it feeds, trusting to its similitude to the bark for concealment, and to the strength of its habitation for safety, even if discovered.
It is furnished with a gummy substance, something after the manner of the silk of the Tiger-moth; but instead of spinning that substance into threads, it uses it in the following manner.
Biting little chips of wood from the bark of the tree, the caterpillar glues them together with this natural cement; and so builds an arched house for itself, much about the size and shape of half a walnut-shell. So strongly compacted is this residence, that rain and wind have no effect on it, and a penknife does not find an easy entrance.
One or two of these caterpillars which I brought home modified their dwellings in a curious manner. One of them nibbled to pieces a portion of a cardboard box, and so made a kind of papier-maché house; while others, who were placed under a glass tumbler, and upon a stone surface, simply made their house of the hardened gum. In this state, it appeared as if it had been made of thin horn, and was so transparent that the chrysalis could be seen through the walls.
The caterpillar is common enough, and may be found on the willow or poplar. And a sharp eye will soon learn to detect the winter house, which to an unpractised eye looks as if it were merely a natural excrescence on the bark.
If one of these habitations is found, the best mode of removing it is to avoid touching the dwelling itself, but to cut away the bark round it; and then, by inserting the point of a stout knife, gently raise up the house, together with the bark on which it is placed. This is one of the modes by which an entomologist may find employment even during thewinter months, and others will be mentioned in the course of this work.
The moth itself may be seen figured onplate B, fig. 4. It is called the Puss-moth, on account of the soft furry down with which its body is covered, and it is fancifully thought to resemble the fur of the cat.
It is rather a difficult moth to preserve effectually, as it is apt to become “greasy”—that is, to have its whole beauty destroyed by an oiliness that exudes from the body, and gradually creeps even over the wings. The best preservative is to remove the contents of the abdomen, and stuff it with cotton-wool that has been scented with spirits of turpentine. But even that plan is rather precarious, and the delicate, downy plumage is apt to be sadly damaged during the process of stuffing.
Still keeping to the same plate, and referring to the right-hand corner at the top, a moth of strange aspect will be seen; and immediately below it an object that somewhat resembles the hammock of the Tiger-moth, affixed in a perpendicular instead of an horizontal direction. This moth is called the Burnet-moth, and the hammock is the pupa case of the same insect.
The colouring of this moth is very rich and beautiful. The two upper wings are green, and of a tint so deep that, like green velvet, they almost appear to be black. On each of these wings are several redspots, varying in number according to the species; some wearing six spots, and others only five. The two under wings are of a carmine red, edged with a border of black, in which is a tinge of steely blue. The body is velvety black, with the same blue tint.
The moth is rather local; but when one is found in a field, hundreds will certainly be near.
At the best of times it is not an active insect, and on a cold or a dull day hundreds of them may be seen clinging to the upright grass stems, from which they can be removed at pleasure.
The caterpillar of this beautiful moth keeps close to the ground, and feeds on grasses, the speedwell, dandelion, and other plants. When it is about to become a pupa, it ascends some slender upright plant, generally a grass stem, and then spins for itself the residence which is represented on the plate.
In this state it may be gathered, and placed under a glass shade; and in the summer months the perfect insect will make its appearance. There are some places which it specially favours, and where it may be found in great profusion. At Hastings, for example, the fields about the cliffs were so populated by these moths, that hardly a grass stem was without its Burnet-moth’s habitation.
Feeding on the same plant as the Tiger-moth caterpillar, may often be found another caterpillar of a very different aspect. It is very much larger,and instead of presenting an array of stiff bristles, is covered with thick soft hair of a yellowish-brown colour, diversified with stripes of a deep velvety black, arranged so as to resemble the slashed vestments that were so fashionable some centuries ago.
This caterpillar is the larva of the Oak Egger-moth, and is not so remarkable as a caterpillar as for the house which it builds for its pupal residence.
After changing its skin the requisite number of times, the caterpillar ceases to feed, and, proceeding to some convenient spot (generally a faded thorn-branch), spins its temporary habitation. This cocoon, as it is called, is about an inch in length; and into that narrow space the creature contrives to push, not only itself, but also its last and largest skin.
The substance of the cocoon is hard and rather brittle when dry; and in texture somewhat resembles thin brown cardboard. In its substance, and on its surface, are woven many of the hairs with which the caterpillar is furnished. If the cocoon is carefully opened, the chrysalis will be found within, its head towards the spot where the moth is to emerge, and the cast caterpillar-skin crumpled down by its tail.
In course of time, the chrysalis passes through its development, and the egger-moth itself pushes its way out of the cocoon, with wings and body wet and wrinkled, but soon to assume their proper form and strength. The cocoon is shown atplate I, fig. 5a.
Sometimes the cocoon remains unbroken beyond the proper season; and if it is examined, one or two little holes will generally be found in it. These are signs that the egger has met with an untimely fate, and that it has fallen a victim to those scourges of the insect world, the ichneumon flies. Of these creatures we shall speak in a future page, and therefore omit to describe them here. The moth is shown at fig. 5.
If the moth is intended to be killed, and then placed in a cabinet, the use of sulphur must be avoided. It kills the moth, certainly; but it kills the colours also, and quite ruins its appearance. Sulphur is always a dangerous instrument in insect-killing, and should on no account be used. There are many ways of destroying insects humanely, and extinguishing their life as if by a lightning flash; but these modes vary according to the size, sex, and nature of the insect. Some of them I will here mention.
If the insect is a beetle, it may be plunged into boiling water, or into spirits of wine, in which a very little corrosive sublimate has been dissolved. Both modes will destroy the life rapidly, but the former is the better of the two. When walking in the fields or woods, a wide-mouthed, strong bottle, about half full of spirits of wine, is a useful auxiliary, as all kinds of beetles, and even flies and bees, can be put into it; and if dried in a thorough draught, willlook as well as before. If this precaution be not taken, all the insects that have long hair, as the humble-bee and others, will lose their good looks, and their hair will be matted together in unseemly elf-locks.
Butterflies, and most of the Diptera, or two-winged flies, can be instantaneously killed by a sharp pinch on the under-surface of the thorax among the legs, as the great mass of nerves is there collected. Many people seem to fancy that the head is the vital part in an insect; and having pinched or run a pin through its head, they think that they have effectually slain the creature, and marvel much to see it lively some twenty-four hours afterwards.
Especially is this the case with the large-bodied moths, whose vitality is quite astonishing. You may even stamp upon them, and yet not crush the life out of that frail casket. If you drive the life out of one-half of the creature, it only seems to take refuge in the other; and then retain a more powerful hold, like a garrison driven into a small redoubt.
It is not at all uncommon to find one of these moths dead and dry as to its wings and limbs, which snap like withered sticks if touched, and yet with so much life in it as to writhe its abdomen if irritated, and to deposit its eggs just as if it were in full activity.
Indeed, so strong is this power that the creature seems to be gifted with a double life, one for itselfand the other for its progeny. The former is comparatively weak, and but loosely clings to its home; but the latter intrenches itself in every organ, penetrates every fibre, and, until its great work is completed, refuses to be expelled. So, unless the entire mechanism of the insect be killed, the poor creature may live for days in pain.
Fortunately, there is a mode of so doing; and this is the way of doing it:—
Make a strong solution of oxalic acid, or get a little bottle of prussic acid—it is the better of the two, if you have discretion as beseems a naturalist. Also make a bone or iron instrument, something like a pen, but without a nib. Dip this instrument into the poison as you would a pen, and then you have a weapon as deadly as the cobra’s tooth, and infinitely more rapid in its work. Now hold your moth delicately as entomologists hold moths, near the root of the wings. Keep the creature from fluttering; plunge the instrument smartly into the thorax, between the insertion of the first and second pair of legs; withdraw it as smartly, and the effect will be instantaneous. The moth will stretch out all its legs to their full extent; there will be a slight quiver of the extremities; they will be gently folded over each other; and you lay your dead moth on the table.
The reason of this rapid decease is of a twofold nature.
In the first place, the chief nerve mass is cut asunder, and even thus a large portion of the life is destroyed. But the chief breathing tubes are also severed, and a drop of poison deposited at their severed portions. Consequently, at the next inspiration, either the poison itself or its subtle atmosphere rushes to every part, and to every joint of the insect, thus carrying death through its whole substance.
The male insect is very different in appearance to the female, and in general is hardly more than two-thirds of her size. The colours, too, are very different; for in the male insect the wings are partially of a dark chestnut brown, with a light band running round them, as may be seen in the engraving; while in the female the wings are almost entirely of a uniform yellowish brown.
The antennæ, too, of the male are deeply cleft, like the teeth of a comb; while those of the female are narrow, and comparatively slightly toothed.
As is the case with several other moths, the male oak eggers are sad victims to the tender passion, and fall in love not only at first sight, but long before they see the object of their affection at all.
If a female egger is caught immediately after her entrance into the regions of air, and placed in a perforated box near an open window, her unseen charms will be so powerfully felt by gentlemen of her own race that they will flock to the casket that contains their desired treasure, and fearlessly runabout it, fluttering their wings, and striving to gain admission. So entirely do they abandon themselves to the captivity of love, that they do not fear the risk of a bodily captivity, and will suffer themselves to be taken by hand, without even an endeavour to escape.
Carry the imprisoned moth into the fields, and even there the eager suitors will arrive from all quarters, and boldly alight on the box while in the hand of the entomologist.
More wonderful must be the influence that can emanate from so small a creature, and extend to so great a distance—an influence which, although entirely inappreciable by any human sense, exercises so potent a sway on all sides, and to so great a distance.
The conditions, too, of this mysterious influence are singularly delicate; for after the moth has once found her mate, she may be placed amid a crowd of gentlemen, and not one will take the least notice of her.
Like the young beauty of the ball-room, who whilom attracted to herself crowds of beaux, that fluttered around her, and contended with each other for a look or a smile of their temporary divinity, but who finds herself deserted by the fickle crowd when her election is made; so our Lady Lasiocampa Quercus, after setting all hearts ablaze for a time, makes happy one favoured individual, is deserted bythe many rejected, and left in quiet to the duties of a wife and a mother.
Her married life is but short, for her husband rarely survives his happiness more than a few hours, and she, after making due preparation for the welfare of her numerous family, whom she is never to see, feels that she has fulfilled her destiny, and gives up a life which has now no further object.
There is really something very human in the life even of an insect. Many a life story have I watched in the insect world, which, if transferred to the human world, would be full of interest. There is also one great advantage in the insect life, namely, that as it only consists of a year or two, the events of several successive generations come under the observation of a single historian.
First, a number of tiny, purposeless beings come into the world, spreading about much at random, and seeming to have no other object except to eat. It is but just to them to say that they don’t cry, and are always contented with the food that is given them.
They rapidly increase in size, pass through a regular series of childish complaints, which we mass together under this single term, “moulting,” but which are probably to their senses as distinct as measles, and chicken-pox, and hooping-cough.
They outgrow a great many suits of clothes in a wonderfully short period; they retire for a time tofinish their education; and then come before the world in all the glory of their new attire.
Up to this time they are nearly exactly alike in habits and manners; but, when freed from the trammels that held them, they diverge, each in his appointed way, each exulting for a short space in the buoyancy of youth, and fluttering indeterminately in the new world, but soon settling down to the business for which they were made.
So even in insects a human soul can find a companionship, and a solitary man need never feel entirely alone as long as he can watch the life of a humble moth, and see in that despised creature some manifestations of the same feelings which actuate himself.
And it even seems that, through this companionship, the higher nature communicates itself in some degree to the lower, as is shown by the many instances of men who have tamed spiders and other creatures quite as far removed from the human nature. In such a case it seems very clear that either the higher nature gives to the lower an intelligence not its own, or that it develops powers which would have lain dormant had they not been called forth by the contact of a superior being.
This subject is a very wide one, and well worth following up. But as it runs through the whole creation, and this book is only to consist of a few pages, it must suffice merely to put forth the idea.
To pass to another insect.
Onplate E, and fig. 1 and 1a, may be seen an insect which somewhat resembles the oak egger-moth, and is often mistaken for it by inexperienced eyes. This is the “Drinker” moth, remarkable for the thick furry coat which it wears, as a caterpillar and as a moth, and which it employs in the construction of its cocoon. This moth is one of my particular friends; and I have had hundreds of them from the egg to their perfect state. I had quite a large establishment for the education and development of lepidoptera, and especially favoured the tiger-moth, the oak egger, and the drinker.
The caterpillar of this moth is entirely covered with dense hair, even down to the very feet; and by means of this protection it is enabled to brave the winter frost, needing not to pass the cold months in a torpid state. It is a pretty caterpillar, and very easily recognised by the figure. Its chief peculiarities are the two tufts of hair that it bears at its opposite extremities, and the double line of black spots along its sides.
Generally, it feeds on various grasses, but it is not dainty, as are many caterpillars; and I have always found it to eat freely of the same food as the oak egger larva. This caterpillar is seen at fig. 1b.
When alarmed, it loosens its hold of the plant on which it is feeding, rolls itself into a ring, and drops to the ground, hoping to evade notice among thefoliage. This habit used to be rather perplexing to me, not because the creature could escape by so well-known a trick, but because it would not go into the box prepared for its reception.
It is necessary to have a box of a peculiar form for the collection of caterpillars. If the lid is raised every time that a fresh capture is made, difficulties increase in proportion to the number of caterpillars. For, when some thirty larvæ are in the box, they all begin to crawl out when the lid is opened; and Hercules had hardly a more bewildering task among the hydra’s heads than the entomologist among his captives.
No sooner is the light admitted, than a dozen heads are over the side; and as fast as one is replaced, six or seven more make their appearance. The only remedy is to sweep them all back with a rapid movement of the hand, to shake them all to the bottom, and then to replace the lid as fast as possible. Even with all precaution, caterpillars are crushed; and, besides, they are delicate in their constitutions, and require gentle handling.
So the best plan is to have a tin box made with a short tube, through which the caterpillars can be introduced, and which can be stopped by a cork when the creatures are fairly inside.
Now, although this is a capital contrivance for caterpillars that hold themselves straight, it fails entirely when they curl themselves into a ring andrefuse to be straightened. It is as impossible to straighten a rolled-up hedgehog as a caterpillar in a similar attitude; and if force is used in either case, the creature will be mortally injured. However, gentle means succeed when violence fails, with insects as with men. A Bheel robber will steal the bedding from under a sleeping man without waking him; and, by an analogous process, the refractory caterpillar is lodged in his prison before he is fairly awake to his condition.
The entomologist feels a justifiable pride in executing similar achievements; for there is quite as much force of intellect needed to outwit a caterpillar as a quadruped.
When the drinker caterpillar passes into its pupal state, it makes for itself a very curious cocoon, not unlike a weaver’s shuttle in shape, being large in the middle, and tapering to a point at each end. The texture is soft and flexible, as if the cocoon were made of very thin felt, and the larval hairs are quite distinguishable on its surface. The moth leaves the cocoon about August. For the cocoon see fig. 1c.
COCOON OF THE EMPEROR MOTH.
COCOON OF THE EMPEROR MOTH.
I found that few caterpillars are so liable to the attack of ichneumon flies as those of the drinker moth. A cocoon now before me is pierced with thirteen holes from which ichneumon flies haveissued, having eaten up the caterpillar. The eggs are shown in fig. 1e.
If the reader will now refer toplate C, the central figure will be found to represent a strikingly handsome moth, called, from its gorgeous plumage, the “Emperor Moth”.
Its body is covered with a thick downy raiment, and the wings are clothed with plumage of a peculiarly soft character, which is well represented in the figure. The antennæ, too, are elaborately feathered.
Although the beauty of this insect would entitle it to notice in its perfect state, and the peculiar shape of its larva—(seeplate C, fig. 4a)—would draw attention, yet its chief title to admiration lies in the cocoon which it constructs for its pupal existence.
Externally, there is nothing remarkable in the cocoon; and, as may be seen in the same plate, fig. 4b, it is a very ordinary, rough, flask-shaped piece of workmanship. But if the outer covering be carefully removed, or if the cocoon be divided lengthways, a very wonderful structure is exhibited.
The inventor of lobster-pots is not known, and history has failed to record the name of the man who first made wire mouse-traps with conical entrances, into which the mice can squeeze themselves, but exit from which is impossible.
But, though the principle had not been applied to lobsters or mice, it was in existence ages upon agesago. Before human emperors had been invented, and very probably long before mankind had been placed on our earth, the caterpillar of the emperor moth wove its wondrous cell, and thereby became a silent teacher to the cunning race of mankind how to make mouse-traps and lobster-pots.
For inside the rough outer case, which is composed of silken threads, woven almost at random, and very delicate, is a lesser case, corresponding in shape with its covering, but made of stiff threads laid nearly parallel to each other, their points converging at the small end of the case. See the cut onp. 125.
It will now be seen that the moth when it leaves its chrysalid case can easily walk out of the cocoon, but that no other creature could enter. So within its trapped case the chrysalis lies secure, until time and warmth bring it to its perfection. It breaks from its pupal shell, walks forward, the threads separate to permit its egress, and then converge again so closely that to all appearance the cocoon is precisely the same as when the moth was within.
Now, any observant member of the human race, who had been meditating upon traps, and happened in a contemplative mood to open one of these cocoons, would feel a new light break in upon him, and, Archimedes-like, he would exclaim “Eureka,” or its equivalent, “I have found my trap!” Reverse the process, make the converging threads tolead into instead of out of the trap, and the thing is done. “I will make it of wire, put it on my shelf, and I catch mice and rats. I will make it of osier, sink it to the bottom of the sea, and I catch lobsters and crabs. I will lay it in a rapid, and I catch roach and dace; I will place it under the river banks, and then I have cray-fish.”
So might he soliloquise on the future achievements of his newly-discovered principle. But unless he had the prophetic afflatus strong within him, never would he imagine that in future times his discovery would catch a monarch and an Elector to boot.
ELEPHANT HAWK-MOTH—PRIVET HAWK-MOTH—DIGGING FOR LARVÆ—BUFF-TIPP MOTH—GOLD-TAILED MOTH—CASE FOR ITS EGGS—CURIOUS PROPERTY OF ITS CATERPILLAR-VAPOURER MOTH—LEAF-ROLLERS—GREEN-OAK MOTH—ITS CONSTANT ENEMY—LEAF-MINERS—LACKEY MOTH—EGG BRACELETS.
ELEPHANT HAWK-MOTH—PRIVET HAWK-MOTH—DIGGING FOR LARVÆ—BUFF-TIPP MOTH—GOLD-TAILED MOTH—CASE FOR ITS EGGS—CURIOUS PROPERTY OF ITS CATERPILLAR-VAPOURER MOTH—LEAF-ROLLERS—GREEN-OAK MOTH—ITS CONSTANT ENEMY—LEAF-MINERS—LACKEY MOTH—EGG BRACELETS.
It will be noticed that the insects mentioned in the preceding chapter are mostly remarkable for the cocoons which they construct, and that the peculiarities of the larva and the perfect insect are but casually mentioned. Those, however, which will be noticed in this chapter are chosen because there is “something rare and strange” in the habits and manners of the creatures themselves.
As it will be more convenient to keep to the same plate as much as possible, we still refer toplate G. On casting the eye over the objects there depicted, the strangest and most fantastic shape is evidently that creature which is marked 5a.
The aspect of the creature is almost appalling, and it seems to glare at us with two malignant eyes, threatening the poisoned blow which the horrid tail seems well able to deliver.
Yet this is as harmless a creature as lives, and it can injure nothing except the leaves of the plant on which it feeds. The eye-like spots are not eyes at all, but simply markings on the surface of the skin, and the formidable horn at the tail cannot scratch the most delicate skin.
The creature is in fact simply the caterpillar of a very beautiful moth, represented in fig. 5, and called the Elephant Hawk-moth—elephant, on account of its long proboscis, and hawk on account of its sharp hawk-like wings and flight. The caterpillar may be found in many places, and especially on the banks of streams, feeding on various plants, such as the willow-herbs.
Another kind of hawk-moth is much more common than the elephant, and is represented onplate A; the moth itself at fig. 5, and its caterpillar at fig. 5a.
This is called the Privet Hawk-moth, because the caterpillar feeds on the leaves of that shrub. The colours of both moth and caterpillar are very beautiful, and not unlike in character.
The bright leafy green tint of the caterpillar, and the seven rose-coloured stripes on each side, make it a very conspicuous insect, and raise wishes that tints so beautiful could be preserved. But as yet it cannot be done, for even in the most successful specimens the colours fade sadly in a day or two, and after a while there is a determination towards a blackish brown tint that cannot be checked.
Any one, however, who wishes to try the experiment may easily do so, for there are few privet hedges without their inhabitants, who may keep out of sight, but can be brought tumbling to the ground by some sharp taps administered to the stems of the bushes.
In the winter the chrysalis may be obtained by digging under privet bushes. There the caterpillar resorts, and works a kind of cell in the ground for its reception. It is better not to choose a frosty day for the disinterment, or the sudden cold may kill the insect, and the seeker’s labour be lost.
Should it be desirable to capture the larva and to keep it alive the object can be easily attained; for the creature is hardy enough, and privet bushes grow everywhere. In default of privet leaves, it will eat those of the syringa and the ash. When it reaches its full growth, it should be provided with a vessel containing earth some inches in depth. Into this earth it will burrow, and remain there until the moth issues forth.
Care should be taken to keep the earth rather moist, as otherwise the chrysalis skin becomes so hard that the moth cannot break out of its prison, and perishes miserably.
On the same plate, fig. 4, may be seen a moth of a curious shape, very feathery about the thorax, the head being all but concealed by the dense down, and as difficult to find as the head of a Skye-terrier, werenot its position marked by the antennæ. This is the Buff-tip Moth, so called on account of the upper wing-tips being marked with buff-coloured scales.
The caterpillar, which is represented immediately above, and marked 4a, is a very singular creature, its habits being indicated by the marks on its skin. As soon as the young caterpillars are hatched, they arrange themselves in regular order, much after the fashion of the dark stripes, and so march over leaf and branch, devastating their course with the same ease and regularity as an invading army in an enemy’s land.
When they increase to a tolerably large size, they disband their forces, and each individual proceeds on its own course of destruction. Were it not for the colours which they assume, these creatures would do great damage; but the ground being yellow and the stripes black, the caterpillars are so conspicuous that sharp-sighted birds soon find them out, and having discovered a colony, hold revelry thereon, and exterminate the band.
Comparatively few escape their foes and attain maturity. When they have reached their full age, they let themselves drop from the branches, and when they come to soft ground, bury themselves therein to await their last change. Individuals may often be seen crossing gravel paths, which they are unable to penetrate, and getting over the ground with such speed and in so evident a hurry that theyseem to be aware that birds are on the watch and ichneumons awaiting their opportunity.
There is a very pretty moth covered with a downy white plumage even to the very toes, and carrying at the extremity of its tail a tuft of golden silky hair. From this coloured tuft, the creature bears the name of Gold-tailed Moth. It may often be found sticking tightly to the bark of tree stems, its glossy white wings folded roof-like over its back, and the golden tuft just showing itself from the white wings.
This golden tuft is only found fully developed in the female moth, and comes into use when she deposits her eggs. The moth is shown onplate E, fig. 4.
As the eggs are laid in the summer time, they need no guard from cold; but they do require to be sheltered from too high a degree of temperature, and for this purpose the silken tuft is used.
At the very end of the tail the moth carries a pair of pincers, which she can twist about in all directions; and this tool is used for the proper settlement of the eggs. The moth, after fixing on a proper spot, pinches off a tiny tuft of down, spreads it smoothly, lays an egg upon it, covers it over, and finally combs the hair so as to lie evenly. And when she has laid the full complement, she gives the whole mass some finishing touches, like a mother tucking-in her little baby in the bed-clothes, and smoothing them neatly over it.
The egg masses are common enough, and are readily discovered by means of their bright yellow covering.
The caterpillar of this moth is a very brilliant scarlet and black creature, commonly known by the name of the “palmer-worm,” and to be found plentifully of all sizes.
People possessed of delicate skins must beware of touching the palmer-worm, or they may suffer for their temerity. I was a victim to the creature for some time before I discovered the reason of my sufferings. And the case was as follows.
Being much struck with the vivid colours of the caterpillar, I was anxious to preserve some specimens, if possible, in a manner that would retain the scarlet and black tints. One mode that seemed feasible was to make a very small snuff-box, as ladies call a rectangular rent, in the creature’s skin, to remove the entire vital organs, to fill the space with dry sand, and then, when the skin was quite dry, to pour out all the sand, leaving the empty skin.
After treating six or seven caterpillars in this fashion, I perceived a violent irritation about my face, lips, and eyes, which only became worse when rubbed. In an hour or so my face was swollen into a very horrid and withal a very absurd mass of hard knobs, as if a number of young kidney potatoes had been inserted under the skin.
Of course, I was invisible for some days, and after returning to my work, was attacked in precisely the same manner again. This second mischance set me thinking; and on consultation with the medical department, the fault was attributed to the hot sand which I had been using.
So, when I went again to the work, I discarded sand, and stuffed the caterpillars with cotton wool cut very short, like chopped straw. My horror may be conjectured, but not imagined, when I found, for the third time, that my face was beginning to assume its tubercular aspect.
Then I did what I ought to have done before, went to my entomological books, and found that various caterpillars possessed this “urticating” property, as they learnedly called it, or as I should say, that they stung worse than nettles. Since that time, I have never touched a palmer-worm with my fingers.
It was perhaps a proper punishment for neglecting the knowledge that others had recorded. But I always had rather an aversion to book entomology, and used to work out an insect as far as possible, andthensee what books said about it. Certainly, although not a very rapid mode of work, yet it was a very sure one, and fixed the knowledge in the mind.
On the same plate, fig. 4a, is shown the caterpillar of this moth, a creature conspicuous from the tufts ofbeautifully-coloured hair which are set on its body like camel-hair brushes.
The caterpillar spins for itself a silken nest wherein to pass its pupa state, and in general there is nothing remarkable about the nest. But I have one in my collection of insect habitations that is very curious.
I had caught, killed, and pinned out a large dragon-fly, and placed it in a cardboard box for a time. Some days afterwards, a palmer-worm had been captured, and was imprisoned in the same box. I was not aware that such a circumstance had happened, and so did not open the box for a week or two, when I expected to find the dragon-fly quite dry and ready for the cabinet.
When, however, the box was opened, a curious state of matters was disclosed. The caterpillar had not only spun its cocoon, but had shredded up the dragon-fly’s wings, and woven them into the substance of its cell. The glittering particles of the wing have a curious effect as they sparkle among the silver fibres.
Onplate D, fig. 3a, is represented a creature whose sole claim to admiration is its domestic virtue, for elegance or beauty it has none. It hardly seems possible, but it is the fact, that this clumsy creature is the female Vapourer Moth, the male being represented immediately below fig. 3.
Why the two sexes should be so entirely differentin aspect, it is not easy to understand. The female has only the smallest imaginable apologies for wings, and during her whole lifetime never leaves her home, seeming to despise earth as she cannot attain air.
This moth is not obliged to form laboriously a warm habitation for her eggs, for she places them in a silken web which she occupied in her pupal state, and from which she never travels.
Curiously enough, her eggs are not placed within the hollow of the cocoon as might be supposed, but are scattered irregularly and apparently at random over its surface. Even there, though, they are warm enough, for the cocoon itself is generally placed in a sheltered spot, so that the eggs are guarded from the undue influence of the elements, and at the same time protected from too rapid changes of temperature.
In the hot summer months, the leaves of trees are crowded with insects of various kinds, which fly out in alarm when the branches are sharply struck. Oak trees are especially insect-haunted, and mostly by one species of moth, a figure which is given onplate B, fig. 1.
This little moth is a pretty object to the eyes, but a terrible destructive creature when in its caterpillar state, compensating for its diminutive size by its collective numbers. The caterpillar is one of those called “Leaf-Rollers,” because they roll up theleaves on which they feed, and take up their habitation within.
There are many kinds of leaf-rollers, each employing a different mode of rolling the leaf, but in all cases the leaf is held in position by the silken threads spun by the caterpillar.
Some use three or four leaves to make one habitation, by binding them together by their edges. Some take a single leaf, and, fastening silken cords to its edges, gradually contract them, until the edges are brought together and there held. Some, not so ambitious in their tastes, content themselves with a portion of a leaf, snipping out the parts that they require and rolling it round.
The insect before us, however, requires an entire leaf for its habitation, and there lies in tolerable security from enemies. There are plenty of birds about the trees, and they know well enough that within the circled leaves little caterpillars reside. But they do not find that they can always make a meal on the caterpillars, and for the following reason.
The curled leaf is like a tube open on both ends, the caterpillar lying snugly in the interior. So, when the bird puts its beak into one end of the tube, the caterpillar tumbles out at the other, and lets itself drop to the distance of some feet, supporting itself by a silken thread that it spins.
The bird finds that its prey has escaped, and nothaving sufficient inductive reason to trace the silken thread and so find the caterpillar, goes off to try its fortune elsewhere. The danger being over, the caterpillar ascends its silken ladder, and quietly regains possession of its home.
Myriads of these rolled leaves may be found on the oak trees, and the caterpillars may be driven out in numbers by a sharp jar given to a branch. It is quite amusing to see the simultaneous descent of some hundred caterpillars, each swaying in the breeze at the end of the line, and occasionally dropping another foot or so, as if dissatisfied with its position.
Each caterpillar consumes about three or four leaves in the whole of its existence, and literally eats itself out of house and home. But when it has eaten one house, it only has to walk a few steps to find the materials of another, and in a very short time it is newly lodged and boarded.
The perfect insect is called the “Green Oak Moth”. The colour of its two upper wings is a bright apple green; and as the creature generally sits with its wings closed over its back, it harmonises so perfectly with the green oak leaves, that even an accustomed eye fails to perceive it. So numerous are these little moths, that their progeny would shortly devastate a forest, were they not subject to the attacks of another insect. This insect is a little fly of a shape something resembling that of a large gnat; and whichhas, as far as I know, no English name. Its scientific title is Empis. There are several species of this useful fly, one attaining some size; but the one that claims our notice just at present is the little empis, scientifically Empis Tessellata.
I well remember how much I was struck with the discovery that the empis preyed on the little oak moths, and the manner in which they did so.
One summer’s day, I was entomologising in a wood, when a curious kind of insect caught my attention. I could make nothing of it, for it was partly green, like a butterfly or moth, and partly glittering like a fly, and had passed out of reach before it could be approached. On walking to the spot whence it had come, I found many of the same creatures flying about, and apparently enjoying themselves very much.
A sweep of the net captured four or five; and then was disclosed the secret. The compound creature was, in fact, a living empis, clasping in its arms the body of an oak moth which it had killed, and into whose body its long beak was driven. I might have caught hundreds if it had been desirable. The grasp of the fly was wonderful, and if the creature had been magnified to the human size, it would have afforded the very type of a remorseless, deadly, unyielding gripe. Never did miser tighter grasp a golden coin, than the empis fastens its hold on its green prey. Never did usurer suck his client morethoroughly than the empis drains the life juices from the victim moth.
He is a terrible fellow, this empis, quiet and insignificant in aspect, with a sober brown coat, slim and genteel legs, and just a modest little tuft on the top of his head. But, woe is me for the gay and very green insect that flies within reach of this estimable individual.
The great hornet that comes rushing by is not half so dangerous, for all his sharp teeth and his terrible sting. The stag-beetle may frighten our green young friend out of his senses by his truculent aspect and gigantic stature. But better a thousand stag-beetles than one little empis. For when once the slim and genteel legs have come on the track of the little moth, it is all over with him. Claw after claw is hooked on him, gradually and surely the clasp tightens, and when once he is hopelessly captured, out comes a horrid long bill, and drains him dry. Poor green little moth!
Still continuing our research among the oak leaves, we shall find many of them marked in a very peculiar manner. A white wavy line meanders about the leaf like the course of a river, and, even as the river, increases in width as it proceeds on its course. This effect is produced by the caterpillar of one of the leaf-mining insects, tiny creatures, which live between the layers of the leaf, and eat their way about it.
Of course, the larger the creature becomes, the more food it eats, the more space it occupies, and the wider is its road; so that, although at its commencement the path is no wider than a needle-scratch, it becomes nearly the fifth of an inch wide at its termination. It is easy to trace the insect, and to find it at the widest extremity of its path, either as caterpillar or chrysalis. Often, though, the creature has escaped, and the empty case is the only relic of its being.
There are many insects which are leaf-miners in their larval state. Very many of them belong to the minutest known examples of the moth tribes, the very humming bird of the moths, and, like the humming birds, resplendent in colours beyond description. These Micro-Lepidoptera, as they are called, are so numerous, that the study of them and their habits has become quite a distinct branch of insect lore.
Some, again, are the larvæ of certain flies, while others are the larvæ of small beetles. Their tastes, too, are very comprehensive, for there are few indigenous plants whose leaves show no sign of the miner’s track, and even in the leaves of many imported plants the meandering path may be seen.
There are some plants, such as the eglantine, the dewberry, and others, that are especially the haunts of these insects, and on whose branches nearly every other leaf is marked with the winding path. I have now before me a little branch containing seven leaves,and six of them have been tunnelled, while one leaf has been occupied by two insects, each keeping to his own side.
The course which these creatures pursue is very curious. Sometimes, as in the figure onplate A, fig. 1, the caterpillar makes a decided and bold track, keeping mostly to the central portion of the leaf.
Sometimes it makes a confused tortuous jumble of paths, so that it is not easy to discover any definite course.
Sometimes it prefers the edges of the leaves, and skirts them with strange exactness, adapting its course to every notch, and following the outline as if it were tracing a plan.
This propensity seems to exhibit itself most strongly in the deeply cut leaves. And the shape or direction of the path seems to be as property belonging to this species of the insect which makes it; for there may be tracks of totally distinct forms, and yet the insects producing them are found to belong to the same species.
If the twigs of an ordinary thorn bush be examined during the winter months, many of them will be seen surrounded with curious little objects, called “fairy bracelets” by the vulgar, and by the learned “ova of Clisiocampa Neustria”. These are the eggs of the Lackey Moth, and are fastened round the twigs by the mother insect, a brown-coloured moth, that may be found in any number at the right time.
It is wonderful how the shape of the egg is adapted to the peculiar form into which they have to be moulded, and how perfectly they all fit together. Each egg is much wider at the top than at the bottom; and this increase of width is so accurately proportioned, that when the eggs are fitted together round a branch, the circle described by their upper surfaces corresponds precisely with that of the branch.
These eggs are left exposed to every change of the elements, and are frequently actually enveloped in a coat of ice when a frost suddenly succeeds a thaw. But they are guarded from actual contact with ice and snow by a coating of varnish which is laid over them, and which performs the double office of acting as a waterproof garment and of gluing the eggs firmly together. So tightly do they adhere to each other, that if the twig be cut off close to the bracelet the little egg circlet can be slipped off entire.