This extensive sub-order includes the Cicadas, Lantern Flies, Plant
Lice, Scale Insects, etc.
[Illustration: Fig. 97.--Fulogra Horsfieldi.]
As already pointed out, the most striking general character of this
group consists in the uniform texture of the forewings.
[Illustration: Fig. 98.--Cixius Cunicularius (Mag.)]
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.
[Illustration: Fig. 99.--Delphax Longipennis.]
[Illustration: Fig. 100.--Derbe Strigipennis (Mag.)]
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.
[Illustration: Fig. 101.--Issus Coleoptratus.]
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.
[Illustration: Fig. 102.--Tettigometra Virescens (Mag.)]
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.
[Illustration: Fig. 103.--Pœciloptera Phalænoides (Mag.)]
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.
[Illustration: Fig. 104.--Membracis Foliata (Mag.)]
_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.
[Illustration: Fig. 105.--Smilia Fasciata (Mag.)]
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.
[Illustration: Fig. 106.--Œda Inflata (Mag.)]
_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.
[Illustration: Fig. 107.--Physoplia Nigrata (Mag.)]
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."
[Illustration: Fig. 108.--Hypsauchenia Westwoodii (Mag.)]
_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.
[Illustration: Fig. 109.--Heteronotus Vulneratus (Mag.)]
[Illustration: Fig. 110.--Jassus Atomarius (Mag.)]
_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.
[Illustration: Fig. 111.--Bythoscopus Venosus (Mag.)]
[Illustration: Fig. 112.--Livia Juncorum (Mag.)]
_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.
[Illustration: Fig. 113.--Darnis Limacodes (Mag.)]
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.
[Illustration: Fig. 114.--Tricophora Sanguinolenta (Mag.)]
[Illustration: Fig. 115.--Aphis Tiliæ (Mag.)]
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.
[Illustration: Fig. 116.--Lachnus Quescus (Mag.)]
The reproduction of the _Aphidæ_ constitutes one of the most
interesting chapters in the history of the animal kingdom.
[Illustration: Fig. 117.--Aleyrodes Proletella (Mag.)]
_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.
[Illustration: Fig. 118.--Coccus Cacti (Mag.)]