Part 3

_Family 5, Psocidæ._--This is a family of small insects with simple veined wings. They have a rather large head, and bear a pair of long tapering antennæ. They are found upon trunks of trees, old palings, walls, etc. They are very active in their movements, and generally appear in the imago state about the end of summer or beginning of autumn.

_Atropos pulsatorius_ is one of these. It lives in books and among old damp papers, whence it is often called the "Book Louse."

They are also very destructive to collections of preserved insects and plants. About thirty species occur in this country.

_Family 6, Embiidæ._--This family contains no representative in the British Isles, and consists of a small number of almost exclusively exotic species. Two species, however, inhabit the continent of Europe, one of which, _Embia Solieri_, occurs in the south of France on the Mediterranean littoral.

These insects are very closely allied to the _Psocidæ_ in their habits.

TRIBE V.--SOCIALIA.

The Socialia contains a very peculiar group of insects closely allied to the cockroaches in the _Orthoptera_. They may be considered a connecting link between that order and the Neuroptera. There is only one family.

_Family 7, Termitiæ._--The _Termitiæ_, or White Ants, are almost exclusively inhabitants of tropical climates, and are unrepresented in our own country.

They are a very remarkable family of insects. They build most complicated dwellings, consisting of innumerable galleries and chambers, and they are so interesting in their habits that every traveller who has seen anything of them has always a great deal to relate concerning them.

One species, _Termes lucifugus_, inhabits the south of France, and is very well known on account of the mischief which it sometimes causes.

TRIBE VI.--PHYSOPODA, OR THRIPS.

This tribe of insects, to which the name _Thysanoptera_ is sometimes applied, contains many curious forms.

There are two principal groups of these insects--namely, the _Tuberlifera_ and the _Terebrantia_. They are generally known to gardeners by the name of "Thrips." Some of them occasionally prove injurious to cultivated plants. This is especially the case with the Corn Thrips (_Thrips cerealium_), which generally attacks the ears of corn, and, when numerous, is very mischievous.

TRIBE VII.--MALLOPHAGA OR BIRD LICE.

These insects, which are known as "Bird Lice," were formerly placed among the true lice, but they differ in the possession of biting mouths, and in the diet to which such a structure adapts them.

A great number of these curious little insects have been recorded, and they inhabit all parts of the world. They live among the feathers of birds and the hairs of mammalia.

Almost every animal and bird is subject to these parasites.

The common fowl, duck, goose, game birds of all kinds, and pigeons, are very commonly infested by them, as are also the dog, the cat, the sheep, and the guinea-pig.

The two principal families of the _Mallophaga_ are the _Philopteridæ_ and the _Liotheidæ_.

TRIBE VIII.--THYSANURA OR BRISTLE TAILS.

The forms composed in this tribe of insects are reckoned at present to be the nearest resemblance to the theoretical progenitors of the insects; in fact, Sir John Lubbock hints that they might well be regarded not as insects at all, but rather as the surviving representatives of a group formed by the ancestors of the whole multitude of insect types.

The food of these creatures consists of decayed vegetable matter.

Three principal families may be recognised--viz., _Lepesmidæ_, _Campodeidæ_, and _Japygidæ_.

TRIBE IX.--COLLEMBOLA OR SPRING TAILS.

These insects closely resemble the previous tribe in general character, to which also the same remarks nearly apply.

They are generally small insects, a length of a quarter of an inch being considerably above the average. They are found commonly in loose earth, under decaying leaves in woods, in moss, under the bark of dead trees, and in rotten stumps. They always prefer damp situations.

Cold seems to have but little effect upon them; they will recover their activity after being frozen. One species, _Desoria glacialis_, is found enjoying itself upon the Swiss glaciers, and another, _Degeeria nivalis_, occurs upon the surface of snow in many parts of Europe. Some species also may be met with hopping about upon the surface of standing water. _Podura aquatica_, a minute blue-black species, is common in such situations in England.

The five principal families are the _Smynthuridæ_, _Papyriidæ_, _Degeeriadæ_, _Poduridæ_, and the _Amouridæ_.

ORDER ORTHOPTERA.

INCLUDING THE GRASSHOPPERS, LOCUSTS, CRICKETS, COCKROACHES, EARWIGS, AND THEIR ALLIES.

The _Orthoptera_ include all those forms of insects which have four wings, the anterior pair being of a leathery nature. They are mandibulate; that is, their mouths are formed for biting, and they undergo an imperfect metamorphosis.

The insects comprised in this order are extremely numerous and destructive in the tropical parts of the world (Kirby gives their number as about 7,000), but they are only represented in the British Isles by about sixty species, few of which are really abundant. They include the cockroaches, crickets, grasshoppers, locusts, earwigs, etc.

All these insects may be divided into three sub-divisions or tribes--namely, the Runners or _Cursoria_, the Leapers or _Saltatoria_, and the Earwigs or _Euplexoptera_.

The following table will show at a glance the outlines of the proposed arrangement:--

_Tribe_ I., _Cursoria_.--Hind wings with veins radiating from the base. Hind legs formed for running.

_Tribe_ II., _Saltatoria_.--Hind wings with veins radiating from base. Hind legs formed for leaping.

_Tribe_ III., _Euplexoptera_.--Hind wings with veins radiating from the apex of a horny piece occupying the base of the anterior margin.

The _Euplexoptera_, or Earwigs, are regarded by some authors as a separate order. They are thus treated by Westwood in his "Introduction to the Modern Classification of Insects," but the modern tendency is to revert to the Linnæan system, and retain them among the _Orthoptera_.

TABULAR VIEW

OF THE

PRINCIPAL FAMILIES OF THE ORTHOPTERA.

TRIBE I.--CURSORIA.

Family 1. Blattidæ or Cockroaches. Family 2. Mantidæ or Praying Insects. Family 3. Phasmidæ or Stick and Leaf Insects.

TRIBE II.--SALTATORIA.

Family 4. Achetidæ or Crickets. Family 5. Gryllidæ or False Locusts. Family 6. Locustidæ or True Locusts and Grasshoppers.

TRIBE III.--EUPLEXOPTERA.

Family 7. Forficulidæ or Earwigs.

We will now proceed to describe each of these families in turn.

TRIBE I.--CURSORIA.

The insects constituting this group are distinguished by having their hind legs adapted for walking or running. They are subdivided into three families.

_Family 1, Blattidæ._--This family includes the numerous species of cockroaches, or "black bats" as they are often called by uneducated persons. They are represented in all parts of the world, but are most abundant within the tropics, and especially in central and southern America, where also the largest and finest species are to be found. Many curious forms are also to be met with in India and different parts of Africa.

They are very active creatures, and run with considerable rapidity, but their activity is chiefly nocturnal, and during the day they generally remain quietly concealed in some obscure retreat. Their diet consists of both vegetable and animal matter, and offal of every description. They are most useful in hot climates, acting the part of scavengers, and by these means preventing the outbreak of malaria and other pestilential diseases.

The best-known species in this country is the common Cockroach (_Blatta orientalis_), which, by-the-bye, is not a native of Europe, having been introduced from the East several centuries ago, and to have made its home here.

Other species besides this are met with occasionally in different parts of the country, having been introduced in like manner at different times from foreign parts. The Giant Cockroach (_Blaberus giganteus_) is one of these. Its native home is South America and the West Indies, and in the latter place it is commonly called the "drummer." It measures nearly three inches in length. The Zoological Gardens in London is a favourite resort of this species.

_Family 2, Mantidæ._--The _Mantidæ_ may be at once distinguished from the insects comprising the other two families of the _Cursoria_ by the structure of the forelegs, which are converted into powerful raptoral organs.

The body of these insects is more or less elongated, and the head, which is triangular or heart-shaped, is attached to the thorax by a distinct neck.

The _Mantidæ_, or Praying Insects, are celebrated for their habit of resting on their four hind legs, and with their front legs raised in the air, in what was formerly supposed to be an attitude of devotion, but really in an observant attitude, and on the alert for their prey.

None of these insects are met with in the British Isles, but several species are rather abundant in the south of France. Two species, _Mantis pauperata_ and _Mantis religosa_, measure about two or two and a half inches in length. A third species, _Mantis oratoria_, is also common but somewhat smaller in size.

_Family 3, Phasmidæ._--These insects very much resemble the _Mantidæ_ in general appearance, to which also they are very closely allied.

They are among the most peculiar insects in existence. Their appearance is comical in the extreme. Many of them resemble sticks, either green growing trees or brown and withered branches, and hence the name of stick insects commonly applied to them is very appropriate. On account of their skeleton-like forms they have also been likened to ghosts and spectres.

Some few species mimic leaves of trees and various plants, and these are often called "leaf insects."

The number of species of this family is not very large, and by far the greater part of these are inhabitants of the warmer regions of the earth, and they seem to increase in size, especially the nearer their home lies to the Equator.

Among the more interesting species we may mention _Cyphocrania semirubra_ from Brazil, with short greenish elytra and pink wings.

_Bacillus rosii_ is a brown, wingless form found in Italy and the south of France.

Some of the tropical species are among the largest insects known. A winged Australian species attains the length of ten inches.

_Lopaphus cocophagus_ is a common species in the South Sea Islands, and sometimes commits great ravages in the plantations of cocoa-nut trees. When this insect is alarmed it squirts out a highly acrid fluid, which causes great pain, and sometimes blindness if it reaches the eye.

We may remark that no species of _Phasmidæ_ are known to inhabit the British Isles.

TRIBE II.--SALTATORIA.

The principal character of the insects belonging to this tribe consists in the adaptation of the hind legs to the purpose of leaping.

The males of most of the species possess the faculty of producing loud chirping sounds, but the means by which this is effected vary in the different families.

_Family 4, Achetidæ._--The most familiar British insect belonging to this family is the common House Cricket (_Acheta domestica_). Living, as it does, in the immediate vicinity of the fire, it seems to be totally independent of the changes of the seasons, and may usually be found of all ages at all periods of the year. Crickets are particularly abundant in bakehouses, being extremely partial to warmth. The chirping noise which they produce at night-time is sometimes almost deafening, and it is really surprising from what a very long distance the sound may be heard.

Their food consists of bread crumbs and scraps of meat and vegetables which have been allowed to accumulate during the daytime. The best way, therefore, to get rid of the insects is to take proper care in clearing away all the refuse after meals, for if this were not there the crickets could not subsist, and would soon quit the house. They are, however, generally objected to only by weak-nerved people, and do very little harm, if any whatever. It is a question whether they are not very useful in acting as scavengers.

A nearly allied British species is the Field Cricket (_Acheta campestris_), which is rather larger than the house cricket. It is comparatively rare and local in this country, but abounds everywhere on the Continent.

A third British species is the Wood Cricket (_Nemolicus sylvestris_), which is considerably rarer than either of the preceding. It is found abundantly among dead leaves in woods in France and other parts of the Continent, but is very rarely found in England.

The Mole Cricket (_Gryllotalpa vulgaris_) is perhaps the most interesting member of the family. It is a large, robust insect, about an inch and a half in length and of a very dark brown colour. It is remarkable for the peculiar shape of its front legs, which exactly resemble those of the mole.

It burrows in loose soil, and, like the mole, it passes along close beneath the surface of the ground, and often raises a small ridge as it advances. It frequents gardens, especially near the banks of canals, and is also fond of damp meadows and other localities in the vicinity of water.

The eggs to the number of 200 or 300, are deposited in a chamber of considerable dimensions, and enclosed in a sort of cocoon-like envelope.

The _larvæ_ when first hatched are white, and are said to be three years in arriving at a state of maturity. The mole cricket is found chiefly in the south of England.

_Family 5, Gryllidæ._--The most conspicuous insect belonging to this family in Britain is known as the great Green Grasshopper (_Phasgonura viridissima_), which measures nearly four inches in expanse of the wing, and is therefore nearly as large as the migratory locust which sometimes visits us.

The great green grasshopper is not, however, a very common insect in this country, being principally confined to the south of the island.

Another European and British species, _Decticus verrucivorus_, is of about the same length. It receives its name from the custom prevailing among the Swedish peasants of making it bite their warts. This insect, in common with many others of the same family, when at all roughly handled, emits from the mouth a brownish fluid, which is said to possess acrid qualities, and the introduction of this into the warts is supposed to cause their disappearance.

_Family 6, Locustidæ._--This family, which includes the grasshoppers and true locusts, is easily distinguished from both the preceding families by the character of the antennæ, which are comparatively short.

The common English Grasshopper (_Rhammatocerus biguttulus_), whose song must be familiar to every one who has walked through the fields during the summer time, is produced by the friction of the hinder thighs against the wing-cases.

The locusts have been celebrated from the dawn of history on account of the terrible ravages which they have committed in various parts of the world; and although many different species have made their appearance in our own country at various times, the climate, fortunately, seems unsuitable for them to live in, and they have, therefore, not been known to breed here.

The Migratory Locust (_Ædipoda migratoria_) is perhaps the best known in this country on account of its visits, many stray individuals of which have visited us at different periods.

Locusts are known all the world over, in fact, nearly every country has a species peculiar to itself. The most extraordinary accounts are on record of the vastness of the swarms which every now and again invade particular districts. They are said sometimes to absolutely darken the sun.

They clear off everything from the surface of the ground as completely as if the place had been visited by fire.

In many eastern countries locusts are relished as articles of food.

The distinctive character of the insects comprised in this group is found in the structure of the wings. The anterior pair are of a horny or leathery consistence, but always much shorter than the abdomen. The hind wings, on the contrary, are of large size, and are composed of a very delicate membrane. There is only one family.

TRIBE III.--EUPLEXOPTERA.

_Family 7, Forficulidæ._--The insects of this family present a great uniformity of structure. They are, for the most part, of nocturnal habits, concealing themselves during the day in crevices under the bark of trees, or in the ground under stones and leaves, etc.

Their food consists almost exclusively of vegetable substances, and are sometimes very injurious to flowers and fruit.

It has been said, however, that they also feed largely on plant lice or aphides, which, if true, give them a very redeeming quality.

The female earwig deposits her eggs under a stone in some cavity in the ground often dug out by her own labour.

Unlike most other insects, the female does not perish as soon as she has laid her eggs, but lives to behold her offspring, brooding over them almost like a hen. But it is distressing to learn that if the mother should die she is immediately devoured by her progeny.

The _Euplexoptera_ are widely distributed over the surface of the earth. The tropical regions, however, can hardly claim any great predominance over more temperate climates as regards either the number or size of the species.

The largest European species (_Forficesita gigantea_), which is an inhabitant of some parts of England, measures about an inch in length of the body.

Our common Earwig (_Forficula auricularia_) is not only found all over Europe, but apparently throughout the greater part of the eastern hemisphere.

Another British species, viz., the little Earwig (_Labia minor_), is also of wide distribution.

The earwig derives its name from its occasionally creeping into the human ear in search of concealment. This has been denied by many authors, but we have personally known instances of earwigs entering the ears of persons lying asleep in fields in the summer time. The insect can be driven out immediately by pouring a little oil into the ear.

Some writers have attempted to prove that the name earwig is a corruption of "earwing," in allusion to the shape of the hind wings; really a very ingenious idea, but incorrect nevertheless.

ORDER HEMIPTERA.

INCLUDING THE LAND BUGS, WATER BUGS, PLANT BUGS, SKATERS, LANTERN FLIES, FROG HOPPERS, APHIDES, AND THEIR ALLIES.

The _Hempitera_ are _Haustellate_ insects; they have four wings, which are membranous and naked. Their metamorphosis is incomplete. The order is a very extensive one. The insects, however, are mostly found in the tropical parts of the world, from whence nearly twenty thousand species have been described. In the British Isles their number reaches nearly a thousand.

The study of the _Hemiptera_ has hitherto been sadly neglected, owing to the great majority of them being very small species.

They include the Plant Bugs, Sand Bugs, Water Bugs, Cuckoo Spits, Froghoppers, Plant Lice, and many other familiar forms. The three great divisions into which they are divided are treated by many entomologists as distinct orders. The following will show under each heading the principal distinguishing character of each group or sub-order as we shall designate them.

_Sub-Order 1, Heteroptera._--Fore wings of a parchment like consistency.

_Sub-Order 2, Homoptera._--Fore wings membranous and naked, similar to the hind ones.

_Sub-Order 3, Anaplura._--Wingless; no metamorphosis.

The _Heteroptera_ are regarded as the highest of the three groups, followed by the _Homoptera_, while the _Anoplura_ constitute a somewhat aberrant series, and are somewhat in the same position as the fleas (_Aphaniptera_) are to the true _Diptera_.

TABULAR VIEW

OF THE

PRINCIPAL FAMILIES OF THE HEMIPTERA.

_Sub-Order 1.--Heteroptera._

TRIBE I.--GEOCORES OR LAND BUGS.

Family 1. Scutelleridæ or Shield Bugs. Family 2. Coreidæ or Land Bugs. Family 3. Lygæidæ or Chinch Bugs. Family 4. Pyrrhocoridæ or Plant Bugs. Family 5. Capsidæ or Sap Bugs. Family 6. Tingididæ or Tree Bugs. Family 7. Cimicidæ or Bed Bugs. Family 8. Reduviidæ or Pirate Bugs. Family 9. Emesidæ or Wolf Bugs.

TRIBE II.--HYDROCORES OR WATER BUGS.

Family 10. Saldidæ or Water Jumpers. Family 11. Hydrometridæ or Skaters. Family 12. Gerridæ or Ocean Bugs. Family 13. Galgulidæ or Shark Bugs. Family 14. Nepidæ or Water Scorpions. Family 15. Notonectidæ or Water Boatmen.

_Sub-Order 2.--Homoptera._

Family 1. Cicadidæ or Cicadas Flies. Family 2. Fulgoridæ or Lantern Flies. Family 3. Membracidæ or Horn Flies. Family 4. Cercopidæ or Froghoppers. Family 5. Tettigonidæ or Meadow Lice. Family 6. Ledridæ or Oak Lice. Family 7. Jassidæ or Elegant Lice. Family 8. Psyllidæ or Plant Lice. Family 9. Aphidæ or Aphides. Family 10. Aleyrodidæ or Powder Flies. Family 11. Coccidæ or Scale Insects.

_Sub-Order 3.--Anoplura._

Family 1. Pediculidæ or True Lice.

SUB-ORDER I.--HETEROPTERA.

The _Heteroptera_ constitute the first sub-order of the _Hemiptera_. They include the True Bugs, an extensive group of very varied structure and habits. The greater part of the terrestrial species feed on plants, though some feed on the blood of animals, while the aquatic species are principally carnivorous in their habits. This sub-order is divided into two tribes.

TRIBE I.--GEOCORES OR LAND BUGS.

This tribe includes the terrestrial species of bugs. It is subdivided into fifteen families.

_Family 1, Scutelleridæ._--This extensive family includes the greater portion of the largest and handsomest species of the Land Bugs.

The insects live upon plants, trees, and shrubs, and feed upon the juices, which they suck out of the soft tissues, many of them especially attacking juicy fruits. The family is very well represented in the warmer parts of the world, where also the most beautifully coloured species are met with.

One of the most handsome representatives in Europe is _Graphosoma lineatum_, which measures nearly half an inch in length. It is reddish in colour and is common on flowers, especially those of the _Umbelliferæ_, but is not met with in our own country.

_Edessa cervus_ is a native of South America, and another pretty species.

The most familiar British species is what is commonly known as the Colewort Bug (_Strachia oleracea_), a very pretty insect, which lives on cruciferous plants, and is said sometimes to be injurious in gardens.