Part 4

Some of the Chinese Bugs belonging to the genus _Tesseratoma_ are the largest species known.

_Family 2, Coreidæ._--This family contains a great number of plant-feeding native and exotic species, varying considerably in shape and structure. The majority of European species are, however, of small size in comparison to those found in tropical parts of the world.

The insects of this family are rarely adorned with bright colours, different shades of brown being the prevailing tints, although a few of them are gaily adorned.

In their general habits they much resemble the Shield Bugs.

Two British species are _Syromastes marginatus_ and _Verlusia rhombea_.

_Family 3, Lygæidæ._--The members of this family are, on the whole, much smaller than the _Coreidæ_, some of the smallest forms of which many of them resemble.

These insects are generally of a red colour, with black bands and spots.

Several species are very injurious to cultivated plants. One of the most destructive of all is _Blissus leucopterus_, a black insect with white fore wings, each of which is marked with a large black triangular spot on the outer edge. It measures about an eighth of an inch in length. The young larva is red. In the United States this insect, which abounds to a considerable extent, is called the "Chinch Bug."

_Family 4, Pyrrhocoridæ._--This family of bugs abounds in all parts of the world, and in Europe and Britain is undoubtedly the most numerously represented of all the families of bugs. A very common species in this country found on nettles is _Phytocoris tripustulatus_, which is about one-sixth of an inch in length, and generally yellowish in colour.

_Family 5, Capsidæ._--This family contains a great number of small species of variegated colours, which feed exclusively on the sap of plants or the juice of fruits.

A rather small species (_Capsus ater_) is common upon herbage. The male is entirely black; in the female the head and thorax are reddish. The genus _Miris_ and its allies include elongated species, which are found chiefly in grassy places.

_Family 6, Tingididæ._--The species of this family differ considerably among themselves in size, structure, and habits; and although the majority of them are carnivorous, others, especially among the smaller species, are herbivorous. One species (_Tingis pyri_), found in our own country, is sometimes very injurious to pear trees.

_Family 7, Cimicidæ._--The type of this family is the common Bed Bug (_Acanthia lectularia_), which is only too well known to most people. Although treated as a British insect, it does not always appear to have been an inhabitant of these islands, but to have made its way here about the beginning of the sixteenth century. Three other British species have been described as inhabiting the dwelling-places of certain animals and sucking their blood. _A. columbaria_ attacks pigeons. _A. hirundinis_ is found in swallows' nests, and _A. pipistrelli_ feeds on bats.

_Family 8, Reduviidæ._--All the insects of this family are predaceous in their habits, and are exceedingly numerous in tropical climates. The largest British species is _Reduvius personatus_, an insect about three-quarters of an inch long, of a blackish-brown colour with reddish legs. It is well furnished with wings, and flies especially in warm summer evenings, when it frequently enters houses, being attracted by the lights. This insect is said to be a great enemy to the bed bug.

Some of the foreign species of _Reduviidæ_ are most formidable insects, such as the great black _Conorrhinus renggeri_ of Chili, which often attacks travellers when camping out.

_Family 9, Emesidæ._--Most of these insects are carnivorous in their habits. The best known species of this family is probably _Plæaria vagabunda_, a brown, delicately-formed insect, which inhabits trees.

TRIBE II.--HYDROCORES OR WATER BUGS.

All the insects belonging to this tribe are either water insects, or found only in the immediate neighbourhood of water. It contains the remaining families of the _Heteroptera_, six in number.

_Family 10, Saldidæ._--The majority of species belonging to this family are small, dull-coloured insects, always found in the neighbourhood, though they are not strictly aquatic.

_Family 11, Hydrometridæ._--The habits of most of these insects are herbivorous, and they are all found near water.

_Hydrometra stagnorum_ is a black or brown insect, more or less tinged with reddish, and about half an inch long. It is found running on the surface of water, or else on the banks or among water plants, but is not so active as some of the other species.

_Family 12, Gerridæ._--This family includes some very familiar insects, which may be seen running over the surface of every piece of water. These insects, of which several species are abundant in Britain, have boat-shaped bodies. The typical form is _Gerris lacustris_, which may be met with almost anywhere. They are predaceous in their habits, feeding upon other insects. Some nearly allied, but mostly very small species, with legs even longer in proportion than those of our common forms, are met with at sea within the tropics, and often at a great distance from land.

_Family 13, Galgulidæ._--This family only includes a few American species, which are generally brown spotted with yellow. _Galgulus oculatus_ inhabits the southern part of the United States, and measures about two-fifths of an inch in length.

_Family 14, Nepidæ._--The species of this family are not very numerous, but are of considerable interest. They are of large size, and very fierce and voracious. The genus _Betostoma_, found in the East Indies and America, includes the largest species of _Heteroptera_, some of which measure four and a half inches in length, and nearly six inches in expanse of the wing. Their food consists of small fish, frogs, etc.

The best-known species in our own country is the Water Scorpion (_Nepa cinerea_), which has the power of inflicting a very painful wound if handled. It measures about an inch in length. In colour it is yellowish-grey, the back of the abdomen being red, and its large front legs, which somewhat resemble the claws of a scorpion, have given rise to the name by which it is popularly known. It is very common in stagnant water.

_Family 15, Notonectidæ._--These insects are commonly known as "Water Boatmen," from their habit of rowing themselves about on their backs with their long hind legs. They are carnivorous, feeding on small insects and other "fry."

The most typical British species is _Notonecta glauca_, a yellowish insect about half an inch long. It is a most predaceous insect, and can bite severely.

Another common species inhabiting our own country is _Coriax Geoffroyi_, which is nearly half an inch long. The _Notonectidæ_ are all very powerful and active creatures.

SUB-ORDER II.--HOMOPTERA.

This extensive sub-order includes the Cicadas, Lantern Flies, Plant Lice, Scale Insects, etc.

As already pointed out, the most striking general character of this group consists in the uniform texture of the forewings.

There are eleven families included in the _Homoptera_, all the species belonging to which feed upon vegetable juices.

_Family 1, Cicadidæ._--These insects are mostly inhabitants of warm climates, and our only British representative of the family (_C. anglica_) is one of the smaller species, the wings only expanding about an inch and a quarter. Four or five hundred species, however, are known to inhabit the world, and some of them attain to considerable dimensions.

They generally live upon trees and shrubs, and obtain their nourishment by piercing the tissues and sucking out the juices of their young tender shoots.

The _Cicadas_ are improperly called "Locusts" both in America and Australia, on account of the chirping noise which they perpetually keep up in the woods, both day and night.

_Family 2, Fugloridæ._--This family includes the Lantern Flies and Candle Flies, which are remarkable for their large size, bright colours, and strange forms. They are almost all exotic insects.

The largest species is found in South America, and is called the Great Lantern Fly (_Fulgora laternaria_), measuring nearly three inches in length, and over four inches in expanse of the wings.

The Chinese Lantern Fly (_Fulgora candelaria_) has a red body, the fore wings being greenish with yellow spots, the hind wings orange colour with black tips.

_Cixius nervosus_ is found in the British Isles, chiefly on alders. It measures about a quarter of an inch in length, and in colour is black with yellow legs, and transparent wings dotted with brown.

_Family 3, Membracidæ._--This family is chiefly remarkable for the fantastic shapes assumed by the prothorax.

Most of the species are inhabitants of America, where they occur in wonderful abundance and variety.

A common species, _Centrotus cornutus_, is found in the British Isles and over the greater part of Europe. It is rather over a quarter of an inch long, black, with a pair of upright horns on the prothorax.

Another common European and British species (_Gargara genistæ_) is smaller than the preceding, and has no horns on the prothorax.

_Family 4, Cercopidæ._--The "Froghoppers" and "Cuckoo-spits" belong to this family. They are chiefly small insects found among grass and bushes in the summer.

A very common species in this country is the common Cuckoo-spit (_Aphrophora spumaria_), which is about a quarter of an inch in length, and of a yellowish-grey colour. This insect can make a prodigious leap in proportion to its size. It is said to sometimes spring to a distance of two yards. Its yellow _larvæ_ may often be seen on grass and low plants enveloped in a mass of froth, which has given rise to the name of "Cuckoo-spit."

_Family 5, Tettigonidæ._--These insects are exceedingly numerous, and are often remarkably elegant in form. They are mostly inhabitants of America, where some three or four hundred species have been described, but in England we have an exceedingly pretty species (_Tettigonia viridis_), which is common in damp meadows.

_Family 6, Ledridæ._--Many of the insects belonging to this family resemble beetles somewhat in appearance. _Ledra aurita_, which may be considered the type of the family, is a greenish insect, about three-quarters of an inch in length, and found on oak trees.

_Family 7, Jassidæ._--This family contains a considerable number of small insects, some of them of great beauty and elegant in appearance. The typical genus is _Jassus_.

_Family 8, Psyllidæ._--This is the first family of the so-called "Plant Lice" or "Blight." They resemble the "Froghoppers" in their habits of jumping. Most of them are small insects, and they subsist on the sap of plants, to which they are sometimes injurious. A few species produce galls.

_Livia pyri_ is a reddish insect, abundant on pear trees. Other common species are found on the alder, ash, oak, and nettle.

_Family 9, Aphidæ._--The _Aphidæ_, or "Plant Lice," "Blight," and "Green Fly," as they are variously called, are amongst the most destructive of insects. They are small and feeble creatures, but make up for their individual insignificance by their immense numbers.

They sometimes exist in countless millions, completely smothering the plants upon which they feed.

Migratory habits seem to be strongly developed among the _Aphidæ_, hence it is we are so suddenly visited by such enormous quantities of the insects during hot weather in the summer time.

In colour the _Aphides_ are generally green, brown, and black, according to the species. Different kinds live on different plants and trees.

The Hop Aphis (_Aphis humuli_) lives upon the hop, and its abundance or scarcity is a most important matter to the hop-growers in this country.

One of the most destructive insects of the whole family is the Vine Aphis (_Phylloxera vastatrix_), which has committed terrible ravages at various times in most of the vine-growing districts on the Continent.

The Aphides have the habit of discharging a sweet sticky substance called honeydew, of which ants are very fond.

The reproduction of the _Aphidæ_ constitutes one of the most interesting chapters in the history of the animal kingdom.

_Family 10, Aleyrodidæ._--Many of the insects of this family resemble moths in appearance. Indeed, the typical species, _Aleyrodes proletella_, a very small reddish insect, was formerly considered to be a moth by the older writers on entomology.

_Family 11, Coccidæ._--This family contains the Cochineal Insects, the Scale Insects, and their allies.

The _Coccidæ_, or Scale Insects, are sometimes very injurious to cultivated plants, but they are also useful, producing cochineal, shellac, manna, and other substances of considerable importance.

The Cochineal Insect (_Coccus cacti_) is a native of Mexico, and furnishes us with the most valuable and durable red dye that we possess, and the Lac Insect (_Coccus lacca_), an East Indian insect, produces the well-known lac-dye.

The common Scale Insect (_Coccus adonidum_) is well known in hothouses and conservatories in our own country, though it is not indigenous, having been imported from abroad.

SUB-ORDER III.--ANOPLURA.

This sub-order contains only one family, which is considered to be the last and lowest group of the _Hemiptera_, of which it may be regarded as a very degenerate form. The insects have no wings, and live upon the blood of other animals.

_Family 1, Pediculidæ._--The "Lice" are a very extensive family, but at present not very well known. Almost every mammal has a louse peculiar to itself.

Three species infest man. The Head Louse (_Pediculus capitis_), found on the head, especially in children. The Body Louse (_Pediculus vestimenti_), found in the clothes; and the Crab Louse (_Phthirius inquinalis_), a broader and shorter insect, found in the hair on the face and body of uncleanly persons.

The lice infesting different races of men differ in colour--thus, those found on niggers are black; and those on Europeans are whitish.

Other species of lice infest the dog, cat, pig, mouse, elephant, monkey, etc.

The _Pediculidæ_ undergo no metamorphoses.

ORDER DIPTERA.

INCLUDING THE GNATS, MIDGES, CRANE FLIES, HAWK FLIES, BEE FLIES, BREEZE FLIES, BOT FLIES, AND THEIR ALLIES.

The _Diptera_, or two-winged flies, are among the most numerous orders of insects, but they have been so little studied hitherto that we have but a very imperfect knowledge of them, especially as regards the tropical species.

The number recorded in the British Isles is about 3,000, that of the whole world probably exceeds 30,000, and it is certain that this number will be increased immensely as time goes on.

The _Diptera_ may be defined as insects with a sucking mouth (_Haustellate_), and with only two wings, which are membranous, while the hind wings are represented only by a pair of small knotted organs, called _halteres_. Their metamorphoses are complete.

The _larvæ_ are footless "grubs," generally with a soft body, but sometimes leathery or even nearly horny. Many of them possess a distinctly marked head, which may contain _ocelli_, but in the majority the head appears as if it were simply one of the neighbouring segments.

Their food generally consists of decayed animal and vegetable matter, and thus they are very useful as scavengers, particularly in hot climates.

The _larvæ_ frequently live in the substance upon which they feed, while others reside in water, and many are parasitic.

For the classification of the _Diptera_ we owe much to that eminent entomologist, Osten-Sacken, whose arrangement has been here generally adopted.

TABULAR VIEW

OF THE

PRINCIPAL FAMILIES OF THE DIPTERA.

TRIBE I.--NEMOCERA.

Family 1. Cecidomyiidæ or Wheat Midges. Family 2. Mycetophilidæ or Army Worms. Family 3. Simuliidæ or Sand Flies. Family 4. Bibionidæ or Garden Flies. Family 5. Blephariceridæ or Blood Flies. Family 6. Culicidæ or Gnats. Family 7. Chironomidæ or Midges. Family 8. Orphnephilidæ or Bread Flies. Family 9. Psychodidæ or Fungus Midges. Family 10. Tipulidæ or Crane Flies. Family 11. Dixidæ or Wood Gnats. Family 12. Rhyphidæ or Dung Midges.

TRIBE II.--BRACHYCERA.

Family 13. Xylophagidæ or Tree Flies. Family 14. Cœnomyiidæ or Poplar Flies. Family 15. Stratiomyiidæ or Manure Flies. Family 16. Acanthomeridæ or Pomade Flies. Family 17. Tabanidæ or Breeze Flies. Family 18. Leptidæ or Fox Flies. Family 19. Asilidæ or Hawk Flies. Family 20. Midaidæ or Wolf Flies. Family 21. Nemestrinidæ or Flower Flies. Family 22. Bombyliidæ or Bee Flies. Family 23. Therevidæ or Hairy Flies. Family 24. Scenopinidæ or Window Flies. Family 25. Acroceridæ or Sloth Flies. Family 26. Empidæ or Little Hawk Flies. Family 27. Dolichopodidæ or Fairy Flies. Family 28. Lonchopteridæ or Water Flies. Family 29. Syrphidæ or Dart Flies. Family 30. Conopidæ or Wasp Flies. Family 31. Pipunculidæ or Hedge Flies. Family 32. Platypezidæ or Fungus Flies. Family 33. Œstridæ or Bat Flies. Family 34. Muscidæ or Meat Flies.

_Section 1.--Calypteræ._

Sub-family 1. Tachininæ or Parasitic Flies. Sub-family 2. Descinæ or Rainbow Flies. Sub-family 3. Sarcophaginæ or Screw Worms. Sub-family 4. Muscinæ or Blow Flies. Sub-family 5. Antromyiinæ or Summer Flies.

_Section 2.--Acalypteræ._

Sub-family 6. Scatophaginæ or Dung Flies. Sub-family 7. Ortalinæ or Wood Flies. Sub-family 8. Trypetinæ or Fruit Flies. Sub-family 9. Piophilinæ or Cheese Flies. Sub-family 10. Diopsinæ or Horn Flies. Sub-family 11. Chloropinæ or Corn Flies. Sub-family 12. Drosophilinæ or Mould Flies. Sub-family 13. Agromyzinæ or Holly Flies.

Family 35. Phoridæ or Plant Flies.

TRIBE III. HOMALOPTERA.

Family 36. Hoppoboscidæ or Forest Flies. Family 37. Nycteribidæ or Bat Lice. Family 38. Braulidæ or Bee Lice.

TRIBE IV. APHANIPTERA.

Family 39. Pulicidæ or Fleas.

The number of families comprised in the _Diptera_ is so great that space will only permit us to deal very briefly with each.

TRIBE I.--NEMOCERA.

This tribe contains many well-known insects--namely, the Midges, Gnats, Daddy-longlegs, etc., which are divided into twelve families.

_Family 1, Cecidomyiidæ._--These are small delicate species, generally clothed with long hair. They are all vegetable feeders, some of them being very destructive to crops. The Hessian Fly (_Cecidomyia destructor_) is probably one of the best-known species, on account of the terrible mischief which it has caused in various countries, and particularly in the United States of America. Miss E. A. Ormerod, the well-known economic entomologist, has recently written a great deal concerning this insect, with the view to preventing its increase in our own country.

The Wheat Midge (_Diplosis tritici_) is another very mischievous species.

_Family 2, Mycetophilidæ._--These are generally small species. They are all vegetable feeders. The _larvæ_ live gregariously in fungi, rotten wood, bark, etc.

The Army Worms (_Sciara_) of America, which belong to this family, sometimes congregate in enormous numbers.

The flies are remarkable for their remarkable powers of leaping.

_Family 3, Simuliidæ._--This family includes only one genus, _Simulium_.

It is, however, widely distributed, and some of the species, which are popularly called Sand Flies, are exceedingly annoying in hot climates.

_Family 4, Bibionidæ._--Several species belonging to this group are very familiar insects. Among them is the St. Mark's Fly (_Bibio Marci_), which is black, with transparent wings in the male and brownish in the female.

These flies appear in the spring, and their _larvæ_ live in dung or damp earth.

Many of the species are popularly called "garden flies."

_Family 5, Blephariceridæ._--These flies have long legs, the _antennæ_ are usually long and slender, and the wings broad and long. The type of this family is _Blepharicera fasciata_, the female of which is a very blood-thirsty creature. It is a dark brown fly, with transparent wings and yellow legs, and it measures about one-third of an inch in length. It is, however, by no means abundant.

_Family 6, Culicidæ._--The _Culicidæ_, or Gnats, are a very extensive family.

The _larvæ_ are nearly all aquatic.

They are generally small, dull-coloured insects, and are often called "Mosquitoes" in the country. These insects frequently cause much annoyance during the summer months to persons engaged in out-door occupations. They are particularly abundant in damp meadows, in the vicinity of water, and also in hay-fields, where the face and hands of the mowers are sometimes blistered to much pain by the suckers of the little creatures.

One of the most troublesome species is probably the House Gnat (_Culex ciliaris_), which, thirsting for its evening meal, often enters our apartments, sounding its approach by a tolerably loud humming.

_Culex annulatus_ is a little larger, and is said to produce a greater amount of irritation by its bite.

_Family 7, Chironomidæ._--These insects are small delicate insects, much resembling gnats in appearance, and are popularly called "Midges." The _larvæ_ of most of the species are aquatic.

The _larva_ of _Chironomus plumosus_, which is common in stagnant water, is called the "blood worm" from its bright red colour.