MOLE-CRICKET.Photo by W. P. Dando, F.Z.S., Regent's Park.MOLE-CRICKET.A brown insect about 2 inches long. The very broad and flat front legs are used for burrowing.
Photo by W. P. Dando, F.Z.S., Regent's Park.MOLE-CRICKET.A brown insect about 2 inches long. The very broad and flat front legs are used for burrowing.
Photo by W. P. Dando, F.Z.S., Regent's Park.
MOLE-CRICKET.
A brown insect about 2 inches long. The very broad and flat front legs are used for burrowing.
TheSoothsayers, orPraying-insects, are not British, though one or two species are found in the south of Europe. They have long fore legs, the shanks of which are set with a double row of long, curving, sabre-like spines, and when at rest they hold them up as if in the attitude of prayer; but they are really on the look-out for prey, and the long spines are admirably adapted for wounding or grasping the insects which form their food. They also fight fiercely among themselves, and it is no uncommon occurrence for a female to tear to pieces and devour her mate, either during or after their courtship. The soothsayers are often of a green colour, so as to match the grass and leaves among which they live, and thus conceal them from their prey.
TheStick-insects. orSpectre-insects, have some resemblance to the Soothsayers, but are exclusively vegetable-feeders, and have long, sprawling legs, or shorter ones, sometimes more or less lobate; but they never possess prehensile fore legs for seizing prey. The wing-cases are generally quite small; but some species have beautiful large green or pink wings, folded fan-wise, and covered by the stout front border of the wing. Many species are wingless, and of a grey or brown colour, which renders them scarcely distinguishable from dry bits of stick; and among these is the largest living insect known, a grey stick-like species from Borneo, measuring nearly 13 inches from head to tail. Other species have curious excrescences on the legs and body, which make them look like bits of wood overgrown with moss or lichen; while others possess large flat lobes growing from the legs and body, which cause them to be almost indistinguishable from green leaves; and, indeed, these insects are frequently called "Walking Leaves."
LONG-HORNED GRASSHOPPER.Photo by L. H. Joutel][New York.LONG-HORNED GRASSHOPPER.This insect belongs to the same family as the well-known British species. The specimen from which this photograph was taken had unfortunately (as is often the case) broken antennæ; they should be twice as long as the wings.
Photo by L. H. Joutel][New York.LONG-HORNED GRASSHOPPER.This insect belongs to the same family as the well-known British species. The specimen from which this photograph was taken had unfortunately (as is often the case) broken antennæ; they should be twice as long as the wings.
Photo by L. H. Joutel][New York.
LONG-HORNED GRASSHOPPER.
This insect belongs to the same family as the well-known British species. The specimen from which this photograph was taken had unfortunately (as is often the case) broken antennæ; they should be twice as long as the wings.
With theCricketswe commence the last three families of the group, which are distinguished from the others by their power of leaping. The hind legs are very long, with very thick thighs, and generally a double row of strong teeth or spines on the shanks. The feet are generally three-jointed, and there is usually a long ovipositor in the females. There are very few true crickets in England, but three of these are very conspicuous species. The first is theMole-cricket, a large light brown insect nearly 2 inches long, with broad, short front legs rather like those of a mole, which it uses in a similar way. Though common and destructive in fields and gardens, it is not often seen: but if water be thrown on the ground overnight, and a board laid over it, one or two mole-crickets are likely to be found underneath in the morning. TheHouse-cricketresembles this insect in colour, but is not much more than half an inch long, and there is nothing remarkable in the structure of its legs. It is almost the only noisy insect found in English houses, and is very similar to the common cockroach in its habits, although free from the disagreeable smell which adds to the disgust the latter insect often inspires. The third species, theField-Cricket, is a smooth black insect, larger and stouter than the house-cricket. It constructs burrows in grassy places, but is not now a very common species in England. In the last two species, and many others, there is a bare space on one of the wing-cases of the male, crossed by ribs in a manner varying according to the species, which helps to produce the loud chirping for which these insects are remarkable.
CAPE GRASSHOPPER (FEMALE).Photo by J. Edwards][Colesborne.CAPE GRASSHOPPER (FEMALE).This insect, which is remarkable for the inflated bladder-like appearance of the male, is an object of superstition among the Boers. Colour, bright apple-green with white stripes.
Photo by J. Edwards][Colesborne.CAPE GRASSHOPPER (FEMALE).This insect, which is remarkable for the inflated bladder-like appearance of the male, is an object of superstition among the Boers. Colour, bright apple-green with white stripes.
Photo by J. Edwards][Colesborne.
CAPE GRASSHOPPER (FEMALE).
This insect, which is remarkable for the inflated bladder-like appearance of the male, is an object of superstition among the Boers. Colour, bright apple-green with white stripes.
TheLong-horned Grasshoppers, which form the next family, are distinguished by having four joints to their feet, a long ovipositor in the female, and very long, slender antennæ. The commonest species inhabiting England, and one of the largest grasshoppers, is theGreat Green Grasshopper, which is found leaping about among long grass and low bushes, especially in the south of England. It is about 2 inches in length. Among the foreign species of this rather extensive family, we may mention some green or reddish South American species, with a large round spot on the hind wings, not unlike those seen in the peacock-butterfly.
EGYPTIAN LOCUST.Photo by Highley.EGYPTIAN LOCUST.A common North African species, of which specimens occasionally visit England.
Photo by Highley.EGYPTIAN LOCUST.A common North African species, of which specimens occasionally visit England.
Photo by Highley.
EGYPTIAN LOCUST.
A common North African species, of which specimens occasionally visit England.
EGYPTIAN LOCUST.Photo by Highley.EGYPTIAN LOCUST.This figure shows the upper surface of the specimen represented in the preceding photograph.
Photo by Highley.EGYPTIAN LOCUST.This figure shows the upper surface of the specimen represented in the preceding photograph.
Photo by Highley.
EGYPTIAN LOCUST.
This figure shows the upper surface of the specimen represented in the preceding photograph.
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WART-EATING GRASSHOPPER (TWO VIEWS).Photos by W. L. H. Duckworth][Cambridge.WART-EATING GRASSHOPPER (TWO VIEWS).Used by Swedish peasants to bite off their warts.
Photos by W. L. H. Duckworth][Cambridge.WART-EATING GRASSHOPPER (TWO VIEWS).Used by Swedish peasants to bite off their warts.
Photos by W. L. H. Duckworth][Cambridge.
WART-EATING GRASSHOPPER (TWO VIEWS).
Used by Swedish peasants to bite off their warts.
The last family includes theShort-horned Grasshoppers, orTrue Locusts, so very destructive in many countries, though the realMigratory Locustsare only casual visitors to England, the native British species being all small insects, found among grass, and doing but little damage. The commonest of the Migratory Locusts visiting Britain is theRed-legged Locust, which expands from 2 to 4 inches, and has grey wing-cases varied with brown, pale green hind wings, and red hind shanks, with white black-tipped spines. Another species, theEgyptian Locust, more rarely met with, has brown fore wings, and grey hind wings, crossed by a broad blackish band. Two photographs are given on page693of a specimen brought to England among vegetables in the spring of 1901. Many foreign locusts, large and small, have beautiful red or blue hind wings, and some of these are common on the Continent, though not in England; those found in Europe are comparatively small, measuring only 1 or 2 inches across the wing-cases; but some of the great South American locusts measure as much as 7 or 8 inches in expanse. However, some of the smaller species, such as theCyprian Locustand theRocky Mountain Locust, which measure less than 2 inches across the wing-cases, are much more destructive than the large species.
A real invasion of locusts is a terrible calamity, for the insects fly like birds, but in vast flocks, and devour every scrap of vegetation where they settle. Sometimes a flight, two or three miles broad, continues to fly steadily over the same spot for hours together. Sometimes flocks perish at sea, and are cast up on the beach in heaps like sand-hills, extending for a distance of forty or fifty miles. Nor are the young locusts less destructive before they acquire wings; for they march across a district in such numbers as to extinguish fires, fill up trenches, and overcome all similar obstacles placed in their way by sheer force of numbers; and it is well said of a visitation of locusts, "The land is as the Garden of Eden before them, and behind is a desolate wilderness."
NERVE-WINGED OR LACE-WINGED INSECTS, OR DRAGON-FLIES AND THEIR RELATIVES.
BY THE REV. THEODORE WOOD, F.E.S.
The Nerve-winged Insects owe their title to the peculiar character of their wings, the horny veins which form the framework of those organs being multiplied and sub-divided to such an extent that they assume the appearance of exceedingly delicate network.
These insects fall naturally into two great groups, in one of which the chrysalis, or pupa, is active, and continues to take food like the grub, while in the other it is passive and helpless, like that of a butterfly or a moth.
Prominent among the members of the first division are the Dragon-flies, which owe their title partly to their extreme voracity, and partly to the fact that they feed entirely upon living insects, which they pursue through the air. They are exceedingly swift of wing, and may be seen hawking over ponds and streams on any fine day throughout the summer and early autumn.
The earlier part of their lives is spent in the water, in which the eggs are laid by the parent insect. The grubs are usually of a dull grey or brownish-green colour, and are remarkable for a curious organ known as the "mask," which partly covers the lower surface of the head. This apparatus consists of two joints, which fold upon one another, but can be extended at will, the one farthest from the head terminating in a pair of large and powerful jaws. When the grub perceives an insect-victim, it swims cautiously beneath, and seizes it by means of these jaws. The "mask" is then folded, and the prisoner drawn down within reach of the mandibles, by means of which it is speedily devoured.
DRAGON-FLY.Photo by W. P. Dando, F.Z.S.][Regent's Park.DRAGON-FLY.These insects are often known as "Horse-stingers," although they do not sting horses; in fact, they are perfectly harmless, except to insects smaller and weaker than themselves.
Photo by W. P. Dando, F.Z.S.][Regent's Park.DRAGON-FLY.These insects are often known as "Horse-stingers," although they do not sting horses; in fact, they are perfectly harmless, except to insects smaller and weaker than themselves.
Photo by W. P. Dando, F.Z.S.][Regent's Park.
DRAGON-FLY.
These insects are often known as "Horse-stingers," although they do not sting horses; in fact, they are perfectly harmless, except to insects smaller and weaker than themselves.
The method of swimming practised by the dragon-fly grub is also very curious. Through the centre of the body runs a longitudinal tube, terminating in a circular orifice, closed by means of five tightly fitting valves. These valves, which together form a sharp spike when closed, can be separated at will. When the insect wishes to swim, it fills the tube with water, and then squirts the contents forcibly out, the result being that it is driven swiftly forwards by the reaction.
The pupa of the dragon-fly is very much like the grub, with the exception that the rudiments of the future wings may be seen on the back.
About forty species of these insects are found in the British Islands, of which theGreat Dragon-flyis a well-known example. The body is 3 inches in length, while the extended wings measure about 4 inches from tip to tip. In colour it is light rusty brown, with a few pale markings. The "Horse-stinger"—which is perfectly harmless, notwithstanding its popular title—is also common, and may be recognised at once by its flat dull yellow body, which becomes blue in the fully developed male. In the graceful and beautifulDemoisellethe male is deep blue, with black patches on the wings, while the female is entirely green.
Allied to these insects is theCommon May-fly, popularly supposed to live for one day only. As a matter of fact, however, it spends a couple of years in the grub and pupa states, inhabiting burrows in the banks of ponds and streams. These burrows are curved, and havetwo entrances, one above the other, so that the insect can pass in and out with perfect ease.
The May-fly is also remarkable for the fact that the perfect insect changes its skin shortly after reaching maturity. Before this change takes place the female insect is the "Green Drake" of the angler; afterwards, the "Grey Drake."
QUEEN TERMITE.Photo by W. P. Dando, F.Z.S., Regent's Park.QUEEN TERMITE.Her huge white body is full of eggs, of which she lays thousands every day.
Photo by W. P. Dando, F.Z.S., Regent's Park.QUEEN TERMITE.Her huge white body is full of eggs, of which she lays thousands every day.
Photo by W. P. Dando, F.Z.S., Regent's Park.
QUEEN TERMITE.
Her huge white body is full of eggs, of which she lays thousands every day.
To this group belong also theTermites, or "White Ants," so exceedingly numerous in almost all the warmer parts of the world. These are social insects, living together in vast colonies, and making most wonderful nests, which consist of a vast and complicated series of chambers and passages, sheltered beneath a turreted dome of clay. In the centre is the "royal cell," inhabited by the "king" and "queen," as the perfect male and female are called. These are winged when first they leave the pupal shell. But after taking a single flight, they snap off their wings at the base, just as ants do; while for the rest of their lives they are absolute prisoners in the cell built around them by the workers.
Shortly after this strange incarceration takes place, the body of the queen swells to a huge size, so that, to quote Professor Drummond, she becomes "a large, loathsome, cylindrical package, 2 or 3 inches long, in shape like a sausage, and as white as a bolster." She now begins to deposit eggs at the rate of several thousands in a day, which are at once carried off by the workers, to whom is entrusted the entire care of the helpless young. These workers, which are exceedingly numerous, also enlarge the nest from time to time, and construct tunnels of clay up the trunks and along the branches of trees, through which they may convey to the nurseries in security the gums and decaying wood for the nutriment of the young.
A fourth form of insect is also found in the termites' nest, known as the "Soldier." The head is much larger and the jaws are much longer and stronger than those of the worker, and the sole function appears to be to defend the nest when attacked. Both soldier and worker, apparently, proceed from the same eggs which produce the king and queen, the difference in development being probably due—as in the hive-bee—to the character of the food with which the young are supplied.
TERMITES.Photo by W. P. Dando, F.Z.S.][Regent's Park.TERMITES.The perfect male and female are winged, the "worker" and the "soldier" being more like grubs than perfect insects.
Photo by W. P. Dando, F.Z.S.][Regent's Park.TERMITES.The perfect male and female are winged, the "worker" and the "soldier" being more like grubs than perfect insects.
Photo by W. P. Dando, F.Z.S.][Regent's Park.
TERMITES.
The perfect male and female are winged, the "worker" and the "soldier" being more like grubs than perfect insects.
TERMITES' NESTS IN QUEENSLAND.Photo by W. Saville-Kent, F.Z.S.][Milford-on-Sea.TERMITES' NESTS IN QUEENSLAND.These nests are sometimes 14 or 15 feet high.
Photo by W. Saville-Kent, F.Z.S.][Milford-on-Sea.TERMITES' NESTS IN QUEENSLAND.These nests are sometimes 14 or 15 feet high.
Photo by W. Saville-Kent, F.Z.S.][Milford-on-Sea.
TERMITES' NESTS IN QUEENSLAND.
These nests are sometimes 14 or 15 feet high.
TERMITES' NEST IN QUEENSLAND.Photo by W. Saville-Kent, F.Z.S.][Milford-on-Sea.TERMITES' NEST IN QUEENSLAND.The smaller nests, when opened and emptied, are used by the natives as ovens.
Photo by W. Saville-Kent, F.Z.S.][Milford-on-Sea.TERMITES' NEST IN QUEENSLAND.The smaller nests, when opened and emptied, are used by the natives as ovens.
Photo by W. Saville-Kent, F.Z.S.][Milford-on-Sea.
TERMITES' NEST IN QUEENSLAND.
The smaller nests, when opened and emptied, are used by the natives as ovens.
TERMITES AT WORK.Photo by W. Saville-Kent, F.Z.S.][Milford-on-Sea.TERMITES AT WORK.This shows one of the most destructive of wood-eating insects, nearly of the natural size.
Photo by W. Saville-Kent, F.Z.S.][Milford-on-Sea.TERMITES AT WORK.This shows one of the most destructive of wood-eating insects, nearly of the natural size.
Photo by W. Saville-Kent, F.Z.S.][Milford-on-Sea.
TERMITES AT WORK.
This shows one of the most destructive of wood-eating insects, nearly of the natural size.
In a state of nature termites are undoubtedly beneficial. They are scavengers, in fact, whose duty it is to remove the dead and decaying wood which would otherwise encumber the ground for many years. But in civilised districts they are extremely mischievous, books, furniture, and all the woodwork of houses being often completely destroyed by them before their presence is even suspected.
The second division of the order also forms two well-marked groups—namely, the Flat-winged Insects, in which the wings are fully spread, horizontally or obliquely, even in repose, and the Hairy-winged Insects, in which those organs can be folded longitudinally, like the joints of a fan.
Of the former group, theAnt-lionof Southern Europe is a familiar example. The perfect insect is seldom seen, owing to its nocturnal habits. In appearance it is not unlike a small and delicately built dragon-fly, with a yellowish head, a black body, and transparent wings marbled with brownish spots. The larva, however, is terrestrial, and lives in a funnel-shaped pitfall which it scoops out in the sand, always working backwards in a spiral direction, and jerking out the sand with its broad head in an almost continuous shower. Having completed the excavation, it buries itself at the bottom with merely the tips of its jaws appearing above the surface, and there waits for ants or other small creatures to fall down the sloping sides, accelerating their descent, if need be, by flinging sand upon them. The size of the pit varies with that of the insect, the fully grown grub digging down to the depth of about 2 inches, while the cavity is about 3 inches in diameter.
The mouth of the ant-lion grub is very curiously constructed, the jaws lying in a groove on the inner margin of the mandibles, or jaws proper; so that while an insect is held prisoner by the latter, the former can be employed in sucking its juices. When the body of the victim has been completely drained, the empty skin is thrown out of the pit by a jerk of the head.
The chrysalis, too, is remarkable for possessing jaws, by means of which it cuts its wayout of the cocoon which it made, when a larva, by spinning grains of sand together with silken threads.
In some South European and African insects allied to the ant-lions the hind wings are modified into extremely long and slender shafts, slightly expanded at the extremities. In an Indian species belonging to a related genus these wings are scarcely more than threads, and bear a superficial resemblance to the attenuated limbs of certain gnats. One group, of which a Japanese species is a well-known representative, is characterised by the long, slender, and clubbed antennæ.
TERMITES' NEST.Photo by W. Saville-Kent, F.Z.S.][Milford-on-Sea.TERMITES' NEST.Showing one year's reconstruction to nest, of which the photographer made a section.
Photo by W. Saville-Kent, F.Z.S.][Milford-on-Sea.TERMITES' NEST.Showing one year's reconstruction to nest, of which the photographer made a section.
Photo by W. Saville-Kent, F.Z.S.][Milford-on-Sea.
TERMITES' NEST.
Showing one year's reconstruction to nest, of which the photographer made a section.
TheMantis-fliesare remarkable for the structure of the fore limbs, which are almost exactly similar in character to those of the praying-mantis. The upper segment of the leg is so lengthened as to look like an additional joint; the lower surface of the thigh is armed with a number of long, sharp spines; and the tibia, or lower part of the leg, folds closely down upon it, after the manner of the blade of a clasp-knife. These limbs are used for seizing, an insect which is once grasped being effectually prevented by the spines from breaking away.
The larvæ of these insects are parasitic in the nests of tree-wasps and spiders, and have the peculiarity of practically losing their limbs as they approach maturity; so that while at first they are free and active, they afterwards become almost as helpless as those of many beetles. One species is found in Southern Europe, the remainder being widely distributed over the hotter regions of the globe.
Allied to the Mantis-flies are the curiousSnake-flies, orCamel-flies. In these insects the head is very large, and is attached to the thorax, or central division of the body, by a long and distinct neck, which allows it great freedom of motion. The neck is usually raised and the head bent down, giving to the insect a remarkably snake-like appearance.
These flies are predaceous in their habits, and the four British species may be found on the banks of ponds and small streams, where they can obtain insect-victims in plenty. The larvæ live beneath the bark of trees, and wriggle about in a singularly serpentine fashion.
SCORPION-FLY.Photo by W. P. Dando, F.Z.S., Regent's Park.SCORPION-FLY.Remarkable for the curious structure of the end of the body.
Photo by W. P. Dando, F.Z.S., Regent's Park.SCORPION-FLY.Remarkable for the curious structure of the end of the body.
Photo by W. P. Dando, F.Z.S., Regent's Park.
SCORPION-FLY.
Remarkable for the curious structure of the end of the body.
Equally curious in a different way are theScorpion-flies, in which the body is prolonged into a slender three-jointed process, the extremity of which, in the male, is furnished with a pair of curved forceps. In spite of their somewhat formidable appearance these insects are perfectly harmless. They are very plentiful almost everywhere, and may be found in numbers on any sunny summer morning resting on the herbage on hedge-banks, or running actively about on the leaves of low bushes. Like the Snake-flies, they are predaceous, feedingentirely upon other insects, and often attacking those which are bigger and apparently stronger than themselves. The eggs are laid underground, and the grubs, which are entirely subterranean in their habits, feed upon decomposing vegetable matter. When fully fed, they burrow still deeper into the ground, and there change into pupæ, from which the perfect insects emerge about a fortnight later. In the common English species the body is shining black, and the legs are yellow, while the transparent wings are marked with brown spots, which generally form three broken transverse bands. The insect is about half an inch in length.
Certain allied insects have very slender bodies and long legs, and might easily be mistaken for "daddy-long-legs" by any one who failed to notice the presence of two pairs of wings. A species found in Southern Europe is reddish yellow in colour, with a brown thorax and yellowish wings. It has a curious habit of suspending itself from a twig by its fore legs, and seizing any flying insect which may come within reach with the middle and hinder pairs.
ADULT FORM OF ANT-LION.Photo by W. P. Dando, F.Z.S.][Regent's Park.ADULT FORM OF ANT-LION.The grub of this insect lives in small pits in sandy places, and feeds upon the ants, etc., which roll down the sloping sides.
Photo by W. P. Dando, F.Z.S.][Regent's Park.ADULT FORM OF ANT-LION.The grub of this insect lives in small pits in sandy places, and feeds upon the ants, etc., which roll down the sloping sides.
Photo by W. P. Dando, F.Z.S.][Regent's Park.
ADULT FORM OF ANT-LION.
The grub of this insect lives in small pits in sandy places, and feeds upon the ants, etc., which roll down the sloping sides.
Allied to the foregoing is the extraordinary little snow-insect, which makes its appearance in mid-winter, and may even be found crawling on the surface of snow. In general appearance it is not unlike a larval grasshopper, with very long, slender legs, and antennæ of about the same length as the body. There is also a well-developed beak. The wings are quite rudimentary in the female, while even in the male they are so short as to be perfectly useless for flight. The insect is remarkably active, nevertheless, and possesses the power of leaping, although the hinder thighs are not developed in any great degree. In colour it is metallic green, with the beak, antennæ, legs, wings, and ovipositor rusty red. It is not uncommon in the north of England and Scotland.
Far more generally distributed is theLacewing-fly, orGolden-eye, which may be seen almost anywhere on warm summer evenings flitting slowly to and fro in the twilight. During the daytime it may often be found resting upon fences, or sitting on the leaves of lowplants. In colour it is pale green, with a peculiar milky appearance, and the eyes glow as though lighted by an inward fire. The wings are so closely and elaborately veined that they look like a piece of the most delicate lace-work. It is not advisable to handle the insect, for, although perfectly harmless, it possesses the power of pouring out from its body a liquid of the most horrible odour, which clings to the fingers in spite of repeated ablutions.
The life-history of the lacewing-fly is very curious. When the maternal insect lays her eggs, she first deposits a drop of a highly glutinous fluid upon a leaf or slender twig, and then, with an upward jerk of her long body, draws it out into a slender thread. On contact with the air this thread immediately hardens, and just as she releases her hold the fly attaches a single egg to the tip. In this way 200 or 300 eggs are laid together in a little cluster, which looks just like a tiny patch of moss. In the earlier botanical manuals, indeed, it was actually named, figured, and described as a moss.
LARGE CADDIS-FLY.Photo by W. P. Dando, F.Z.S., Regent's Park.LARGE CADDIS-FLY.The largest British species measures about an inch and a half across the wings.
Photo by W. P. Dando, F.Z.S., Regent's Park.LARGE CADDIS-FLY.The largest British species measures about an inch and a half across the wings.
Photo by W. P. Dando, F.Z.S., Regent's Park.
LARGE CADDIS-FLY.
The largest British species measures about an inch and a half across the wings.
The grubs which hatch out from these eggs feed upon plant-lice, of which they devour vast numbers, draining the juices by means of their hollow jaws, and then fastening the empty skins on their own backs, as an American Indian might decorate himself with the scalps of his victims. Owing to this singular habit, the grub becomes perfectly unrecognisable after the first few days of its life, only the jaws and feet being visible beneath the pile of dry skins. When fully fed, it changes to the pupal condition in a silken cocoon, which it attaches to a leaf, and the perfect insect makes its appearance in the course of a few days.
TheAlder-flies, in general appearance, are not unlike caddis-flies, but may easily be distinguished by the fact that the wings are not longitudinally folded while at rest. They are very abundant in the neighbourhood of ponds and small streams, where they may be seen flying slowly and heavily, or resting on low herbage or the foliage of trees and bushes. The female insect lays her eggs in clusters of 300 or 400 on the leaves of water-plants, and the little grubs make their way down into the water immediately on hatching out, where they creep about on the mud at the bottom in search of the tiny creatures on which they feed. When full-grown, they are about an inch in length. They then leave the water and bury themselves in the earth, where they change to pupæ, the perfect insects emerging in June or July.
TheCaddis-flies, of which there are many British representatives, belong to the Hairy-winged group. The larvæ of these insects are entirely aquatic, and remind one of hermit-crabs, the front part of the body being clothed with horny armour, while the hinder part is entirely unprotected. In order to escape the attacks of predaceous insects these grubs construct cases round their bodies, which they drag about wherever they go. In one or two instances, however, the case is attached to the lower surface of a stone.
The materials of which these cases are made vary in accordance with the species. In one group, for instance, they consist of pieces of twigs and leaves, cut into short lengths, and arranged side by side in such a manner as to form a spiral band. The larva of another kind uses entire leaves, gluing them firmly together and living between them. A third species employs grains of sand and tiny stones, which it arranges in the form of a cow's horn. Most curious of all, however, is the case of a caddis-fly which is made entirely of the shells of water-snails. As these shells are, as a rule, still tenanted by their owners, the snails may sometimes be seen attempting to crawl simultaneously in half a dozen different directions, while the grub is dragging them in a seventh.
All the grubs retain tight hold of their cases by means of a pincer-like organ at the end of the body. When fully fed, they close the aperture at each end of the tube, and assume the chrysalis state, the perfect insects emerging a few weeks later. Although the wings are large and broad, they fly very slowly, and never seem to take more than a short journey through the air. They may often be seen in numbers resting upon the herbage on the banks of streams and ponds, or crawling down into the water in order to deposit their eggs.
STINGING FOUR-WINGED INSECTS, OR ANTS, BEES AND WASPS, AND THEIR ALLIES
BY W. F. KIRBY, F.L.S.
The order of insects to which the Ants, Bees, and Wasps belong includes a very large number of species. All these are provided with four membranous wings, alike in consistency, and provided with comparatively few nervures. The wings are usually of small size, as compared with the dimensions of the insects, but are very powerful, owing to the fore and hind pair being connected together during flight by a series of little links; and the flight of the insects is usually very rapid. These insects pass through a perfect metamorphosis, the pupa being always inactive; the jaws are provided with mandibles, though a proboscis, or sucking-tube, is also present, and the abdomen of the female is armed with an ovipositor, or boring instrument, which is frequently modified into a powerful sting, used to deposit the eggs in their proper position. One peculiarity is that several species of ants, bees, and wasps live in large communities, in which the bulk of the inhabitants, on whom most of the work of the nest falls, are imperfectly developed and usually sterile females, called neuters, or workers. This arrangement is also met with in the White Ants, which belong to the order of Lace-winged Insects. Among both the Ants and White Ants the neuters are unprovided with wings; but these organs are present in the fully developed males and females, though soon cast.
SAW-FLY.Photo by W. P. Dando, F.Z.S., Regent's Park.SAW-FLY.One of the commonest of the larger British species is a blackish hairy insect, measuring rather more than an inch in expanse, with transparent wings bordered with brown.
Photo by W. P. Dando, F.Z.S., Regent's Park.SAW-FLY.One of the commonest of the larger British species is a blackish hairy insect, measuring rather more than an inch in expanse, with transparent wings bordered with brown.
Photo by W. P. Dando, F.Z.S., Regent's Park.
SAW-FLY.
One of the commonest of the larger British species is a blackish hairy insect, measuring rather more than an inch in expanse, with transparent wings bordered with brown.
MARBLE GALL-FLY AND GALL.Photo by W. P. Dando, F.Z.S., Regent's Park.MARBLE GALL-FLY AND GALL.Found on oak, and not unlike the foreign gall used for making ink.
Photo by W. P. Dando, F.Z.S., Regent's Park.MARBLE GALL-FLY AND GALL.Found on oak, and not unlike the foreign gall used for making ink.
Photo by W. P. Dando, F.Z.S., Regent's Park.
MARBLE GALL-FLY AND GALL.
Found on oak, and not unlike the foreign gall used for making ink.
A great variety of other insects also belong to this order, such as Saw-flies, Gall-flies, and an immense number of parasitic species, generally called Ichneumon-flies, among which are some of the smallest insects known.
This extensive order of insects is divided into two principal sections—those in which the ovipositor is used as a saw or an auger, and those in which it is modified into a sting. One of the most interesting sections of the Borers includes theSaw-flies, in which the boring instrument is modified into a pair of toothed saws, which are used for cutting incisions in leaves, or in the tender bark of twigs, in which to deposit the eggs. These flies have four transparent wings, sometimes stained with yellow or purple, and their bodies are moderately stout and obtuse, and generally black, red or yellow. The antennæ are very variable in form, and are sometimes knobbed at the end like those of a butterfly; sometimes they are formed of a number of long, slender joints;sometimes of only three—a moderately long basal one, a short middle one, and a long terminal one, composed of a number of joints united into one; and rarely, as in the case of the males of some small species about half an inch long which feed on fir and pine, the antennæ are feathered. The grubs are very like caterpillars, and are sometimes called "false caterpillars"; but a true caterpillar (except in one or two very rare exceptions among foreign species) has never more than sixteen legs, while these "false caterpillars" have more, often as many as twenty-two. They also resemble caterpillars in another way, for the pupæ are enclosed in cocoons. One interesting Australian species, which feeds on gum-trees, proceeds from a black caterpillar with only six legs. The perfect insect has a blackish head and thorax, with three large yellow spots on the latter, yellowish antennæ and wings, and a green abdomen; it measures about an inch and a half across the wings, and has knobbed antennæ. An allied species, found in Tasmania, is said to tend its young larvæ—an unusual habit, except among social insects like bees, wasps, and ants. Among the commonest and the most destructive saw-flies in England are those feeding upon the currant, gooseberry, and pear, of which there are several species, measuring about half an inch across the wings. The commonest flies which lay their eggs on the gooseberry and currant are yellow, with the head, antennæ, and three long spots on the back black, and the wings transparent, with black veins. The grubs are bluish green, with twenty legs, and numerous black dots; and several may often be seen on one leaf. The best-known of thePear Saw-fliesis black, with the wings transparent, except the veins; the grub is very like a slug, and is green or yellow, very slimy, with the front of the body much thickened.
TREE-WASP.Photo by W. P. Dando, F.Z.S., Regent's Park.TREE-WASP.Very similar to the common wasp, but builds its nest in trees instead of in the ground.
Photo by W. P. Dando, F.Z.S., Regent's Park.TREE-WASP.Very similar to the common wasp, but builds its nest in trees instead of in the ground.
Photo by W. P. Dando, F.Z.S., Regent's Park.
TREE-WASP.
Very similar to the common wasp, but builds its nest in trees instead of in the ground.
TheWood-waspsinclude only a few species, the grubs of which live in the stems of plants, or in the solid wood of trees. One of the largest feeds on fir- or pine-trees, and the fly measures from half an inch to an inch and a half in length, and varies much in size, though the male is generally much smaller than the female. The female is yellow, with two black bands, and a stout ovipositor half as long as the abdomen. In the male the tip of the abdomen is black, and ends in a rectangular point. The wings are transparent, with yellow nervures.
TREE-WASP'S NEST.Photo by Scholastic Photo. Co.][Parson's Green.TREE-WASP'S NEST.Generally built in a thick bush.
Photo by Scholastic Photo. Co.][Parson's Green.TREE-WASP'S NEST.Generally built in a thick bush.
Photo by Scholastic Photo. Co.][Parson's Green.
TREE-WASP'S NEST.
Generally built in a thick bush.
Next to these insects come theGall-flies, most of which produce round galls on oaks; and in some species we meet with a wingless brood, living alternately with the winged broods, but at the roots of the trees instead of in the open air. The veining of the wings is reduced to one or two veins; the antennæ are rather long, and not angulated; and the abdomen isshort, and constricted at the base. The flies seldom measure more than half an inch across the wings. Some galls are hard, like the one found on the Turkey oak, from which ink is made; while others are large and juicy, resembling cherries, or small apples, among which is the so-called apple of Sodom. Others, like the Bedeguar, which is found on roses, have a mossy appearance. The latter are produced by a small black saw-fly, with part of the legs, and, in the female, the base of the abdomen, red beneath.
PINE-BORING WASP (FEMALE).Photo by W. P. Dando, F.Z.S.][Regent's Park.PINE-BORING WASP (FEMALE).Formidable in appearance, but quite harmless.
Photo by W. P. Dando, F.Z.S.][Regent's Park.PINE-BORING WASP (FEMALE).Formidable in appearance, but quite harmless.
Photo by W. P. Dando, F.Z.S.][Regent's Park.
PINE-BORING WASP (FEMALE).
Formidable in appearance, but quite harmless.
Some of the smaller gall-flies do not produce galls, but are parasitic on other insects; but galls are very liable to the parasitic attacks of other insects, especially to those of small brilliant metallic green four-winged flies, belonging to an allied family, with very few nervures, but with a black membranous spot on the front edge of the fore wings, and angulated antennæ. Many galls do not begin to grow until the larva is hatched and begins to eat.
We now come to five or six families of parasitic species, popularly calledIchneumon-flies, and immensely numerous and varied. There are probably considerably over 2,000 species in England alone; but they are comparatively little known or studied. Some of these have beautifully delicate wings, fringed with long bristles, and are among the smallest insects known, being of quite microscopic dimensions. These are parasitic on the eggs of various insects, and some are aquatic. But the more typical ichneumon-flies are of larger size, often measuring more than an inch across the wings. Their bodies are usually black or yellow, and there is often an irregularly shaped space in the middle of the fore wing, where the veins of the wing converge. In these flies the ovipositor is very short; but in others it is of great length, especially in the case of the largest British insect of this group, which is parasitic on the larvæ of the great black-and-yellow wood-wasp, of which we have already spoken. This parasite is as large as the wood-wasp, but much more slender; it is black, with red legs, and two white dots on each segment of the abdomen. The ovipositor, which looks like three black threads, is as long as the whole body.
PINE-BORING WASP (MALE).Photo by W. P. Dando, F.Z.S., Regent's Park.PINE-BORING WASP (MALE).Smaller than the female, and very different in appearance.
Photo by W. P. Dando, F.Z.S., Regent's Park.PINE-BORING WASP (MALE).Smaller than the female, and very different in appearance.
Photo by W. P. Dando, F.Z.S., Regent's Park.
PINE-BORING WASP (MALE).
Smaller than the female, and very different in appearance.
The numerous parasites of which we have spoken usually deposit their eggs in punctures in the bodies of caterpillars or other immature insects, which the grubs devour from within during the life of their victim, leaving it to die when they themselves have reached their full growth.
Intermediate between the boring and stinging insects of this order comes the small family of theRuby-tailed Flies. These are brilliantly coloured bronze-red, blue, or green metallic four-winged flies, with the thorax covered with large depressions, and the abdomen smooth, and usually composed, as seen from above, of one large, smooth joint, and one or two much smaller coarsely punctured ones beyond it, the last ending in a variable number of short teeth. They roll themselves up in a ball when alarmed, and are parasites, depositing their eggs in the nests of other insects. An entomologist once saw a ruby-tailed fly hurled to the ground by a mason-bee which had built her nest in a hole in a wall. The fly rolled herself up into a ball, when the bee bit off her wings, and then flew away. But as soon as she was gone the wingless fly stretched herself out again, and climbed up the wall to the bee's nest to deposit her eggs.
CRŒSUS BUTTERFLY OF BATCHIANCRŒSUS BUTTERFLY OF BATCHIANMale natural size
CRŒSUS BUTTERFLY OF BATCHIANMale natural size
CRŒSUS BUTTERFLY OF BATCHIAN
Male natural size
CRŒSUS BUTTERFLY OF BATCHIAN.Photo by W. P. Dando F.Z.S. Regent's Park.Printed at Lyons, France.CRŒSUS BUTTERFLY OF BATCHIAN.Female slightly reduced
Photo by W. P. Dando F.Z.S. Regent's Park.Printed at Lyons, France.CRŒSUS BUTTERFLY OF BATCHIAN.Female slightly reduced
Photo by W. P. Dando F.Z.S. Regent's Park.Printed at Lyons, France.
CRŒSUS BUTTERFLY OF BATCHIAN.
Female slightly reduced
ICHNEUMON-FLY.Photo by W. P. Dando, F.Z.S.][Regent's Park.ICHNEUMON-FLY.One of the largest British species of a very extensive group of parasitic insects.
Photo by W. P. Dando, F.Z.S.][Regent's Park.ICHNEUMON-FLY.One of the largest British species of a very extensive group of parasitic insects.
Photo by W. P. Dando, F.Z.S.][Regent's Park.
ICHNEUMON-FLY.
One of the largest British species of a very extensive group of parasitic insects.
The group of stinging insects begins with theAnts, which are probably the most intelligent animals now living in the world. Different species, however, differ very much in their manners and customs, and in the grade of civilisation to which they have attained. Some of the more industrious among them keep other insects as cattle, and even as pets; others harvest grain, while a few species cultivate grain for their own use; and others make large mushroom-beds of comminuted leaves, and thus do great harm to cultivated trees in many parts of tropical America. When the industrious ants are not too busy, they sometimes indulge in sports and pastimes. But there are some species which live in idle communities. Such ants are only energetic as marauders, and are so degraded that they cannot even feed themselves, and starve to death if they are deprived of the services of their black slaves, which have been carried off as pupæ by the others in piratical raids, and brought up by other slaves, which do all the work in the nests of their captors.
Quitting the Ants, we arrive at a rather extensive series of insects of moderate or considerable size, and with very spiny legs, calledBurrowing-wasps. They are brightly coloured, active insects, and generally dig holes in the ground, which they provision with caterpillars, grasshoppers, or spiders, which they paralyse with their stings, and leave in a moribund condition to form the food of their progeny. They are generally winged in both sexes, but in one family the females are stout and very hairy, and look like large hairy ants, while the males are slender winged insects, very unlike their partners. In the burrowing-wasps the front of the thorax, or second division of the body, is usually transverse, and often narrow; but in theTrue Waspsit bends back to the wings. Among these latter it is only the small group of theSocial Waspswhich are gregarious, and among which we find workers as well as males and females. The largest of the British wasps is theHornet; but there are several much larger species in the East Indies, some of which are black and yellow, like the ChineseMandarin-wasp, the largest of all, which often measures 2 inches across the wings. Others are black, with one large reddish band on the abdomen. Their nests, which they construct of a kind of paper, are formed in a hole in the ground, in a hollow tree, or in a bush, or under the eaves of a house. A nest is commenced by a single female which has survived the winter, and is afterwards enlarged by the exertions of her progeny.