the stalk of the cubitus is either shorter, as long as, or longer than
the lower branch of the cubitus. _Crewiis longipennis_ is of a general
bright red tint, and is ¼ of an inch in length; it ranges from Tasmania
to the North of New South Wales. The larva forms a rounded pale yellow
lerp covered with fine woolly filaments upon the leaves of gum trees.
_Lasiopsylla rotundipennis_ forms a large, flattened, irregularly
rounded white scale on the foliage of _Eucalyptus melliodora_, under
which the flattened, pale green larva hides.
The Sub-family APHALARINAE contains a number of small species, and
the head is produced in front into face lobes, with the stalk of the
cubitus as long as or longer than the stalk of the sub-costa. They
usually form lerp scales; but some are naked, or clothed with soft
white woolly filaments.
Several species of the Genus _Spondyliaspis_ belong to this group; all
of them form “sugar lerp scales,” often encrusting all the foliage
of the young gum trees, and are so abundant that in the Mallee scrub
country in Victoria and S. Australia the blacks used to collect and
eat it in quantities, and had a regular “manna harvest.” _Cardiaspis
artifex_ is a short, reddish yellow insect, the larvae of which form
beautiful barred shell-like lerps, marked with red and yellow to look
like delicate fretwork, upon the leaves of _Eucalyptus robusta_.
_C. tetrix_ is a pretty pink and grey species found in the Adelong
district, N.S.W. The larva constructs a most remarkable cage of fine
red bars, not unlike a lady’s hair net, beneath which the larva
crawls about freely like a bird in a cage. _Rhinocola corniculata_
often covers the leaves of different eucalypts with its elongate,
opaque, horny, yellow lerps. The test is not unlike that of a large
_Mytilaspis_ scale, but is open at the broad end through which the
little larva can creep in and out. It ranges from New South Wales to
Western Australia. _R. eucalypti_ is a very tiny, little, dark brown
psylla, the larvae of which cluster at the tips of the foliage of young
blue gums (_Eucalyptus globulus_), and cover themselves with threads
of white flocculent matter. It was described by Maskell from New
Zealand, but is common both in Tasmania and Australia: it has also been
introduced into Africa on the same eucalypt.
The larvae of the Genus _Thea_ are curious, broad, flattened creatures,
with hard integument. They hide under the dead bark on the trunks of
the white stemmed gums, spreading their white woolly secretion around
them; the ants look after them, and probably protect them from many
enemies in return for the “honey dew,” of which secretion the ants are
very fond. _Thea opaca_ is of a general reddish pink colour mottled
with brown and black; the wings are transparent, with a dark stigma on
the fore wing.
The members of the Sub-family PSYLLINAE have the same well-defined
conical face lobes, but the stalk of the cubitus is shorter than the
stalk of the sub-costa. The larvae may be quite naked, but most of
them produce woolly filaments more or less covering them, and form
no true lerp scales or galls. The typical Genus _Psylla_ comprises a
number of usually small and somewhat stouter insects, many of which
cluster in swarms like aphids upon the foliage of wattles and other
trees. The eggs, larvae, pupae, and perfect insects may be found on
the same twigs. _Psylla acaciae-decurrentis_ is a slender, dark-winged
insect remarkable for the length of its slender antennae; it is
common upon the black wattle in early summer. _P. acaciae-baileyanae_
is a much smaller yellow species with mottled wings that often swarms
over the cultivated “Cootamundra wattle,” and is reported to have
destroyed all the flower-buds of this wattle in the neighbourhood of
Melbourne in 1905. _P. capparis_ is a mottled winged species that
frequents the foliage of _Capparis mitchelli_ in the western scrubs:
_P. schizoneurodes_ infests the twigs of the allied “Warrior Bush”;
the larvae are covered with flocculent matter and have a globule of
liquid substance at the tip of the abdomen; when massed together they
look much like “woolly blight” on the apple trees. _P. sterculiae_ is a
small brownish species, found upon the twigs of the Kurrajong, and has
a wide range over New South Wales.
[Illustration: =Fig. 161.=--_Psylla sterculiae_
(Froggatt).
The Kurrajong Twig Psylla.
(“Agricultural Gazette,” N.S.W.)]
Two very curious species are found upon the thick fleshy leaves of
our native figs, and one, _Mycopsylla fici_, lays her eggs upon the
foliage, the squat grey larvae burying their beaks in the leaf cause a
flow of milky sap, under which they hide in small colonies, and when
ready to emerge crawl from beneath the viscid mass. Where numerous,
they cover the foliage with these sticky patches, and cause the leaves
to fall. The perfect psylla is a handsome, dark-coloured insect with
long antennae and ample transparent wings.
[Illustration: =Fig. 162.=--_Tyora sterculiae_
(Froggatt).
The Star-psylla found on the surface of the leaves of the
Kurrajong.
(“Agricultural Gazette,” N.S.W.)]
Sub-family TRIOZINAE. The cubitus of the wing has no stalk, the veins
forking directly from its junction with the sub-costa. All our species,
with one exception, come into the typical Genus _Trioza_: many of them
are gall makers in the larval state, others are naked and cling to
the under surface of twigs and leaves. The larvae of the gall-makers
are broad, oval, flattened creatures, covered with a mealy secretion,
the outer margin of the dorsal shield in each case being fringed with
fine regular ciliae. Most of the perfect insects are thickset; they
range from chestnut brown to reddish yellow; and have clear transparent
wings. _Trioza carnosa_ makes a large, oval, fleshy, brightly tinted
gall with an irregular opening at the summit, often covering and
aborting the foliage of eucalypts about Sydney. The larva of _T.
eucalypti_ forms a rounded, hard, woody gall upon the leaves, without
any opening on either side until the gall contracts and splits open,
when the full grown pupa emerges. _T. casuarinae_ is a very pretty
little psylla with dark-barred wings, and its curious naked fish-like
larva clings to the slender foliage of the she-oak (_Casuarina_). _T.
banksiae_ has a tiny, naked, yellow larva covered with silvery down; it
is a rare insect found on the under surface of the honeysuckle leaves.
Nearly all these species have been collected within a day’s journey
from Sydney, but have a wide range on the eastern coast.
The Sub-family PRIONOCNEMINAE was formed by Scott for Walker’s Genus
_Tyora_, in which I have placed two species. _Tyora sterculiae_ is a
pale green, aphid-like psylla, with long antennae and large transparent
wings. The larvae cluster together on the leaves of the Kurrajong,
forming white patches over the foliage, and each larva throws out
slender white threads, fringing the tip of the abdomen and radiating
about the body. _T. hibisci_ is a delicate pale green insect which has
been taken on the foliage of _Hisbiscus tiliaceus_, about Brisbane,
Queensland, and also on a creeper on the Tweed River, New South Wales.
Family 7. Aphids or Plant Lice.
APHIDAE.
These destructive little creatures are well known to gardeners under
different names, such as “smother or green-fly,” “plant lice,” or
“blight.” This family contains one of the most destructive and
widespread pests that ever attacked cultivated plants, namely the vine
louse (_Phylloxera vastatrix_), which has destroyed millions of
pounds’ worth of vines, and has followed its host all over the world.
Aphids are all small soft-bodied creatures, green, black, or yellow in
colour; and at least ten introduced species are to be commonly found in
our gardens and fields; but as far as I know, no indigenous aphid is
recorded in Australia.
The life history of these insects is very complex; the winter eggs or
larvae lie dormant during the cold season in crevices on the trunks, or
hidden underground on the roots of their host plants; but as the warm
weather approaches they crawl up the trunks, cluster round the opening
leaf buds, and sticking their sharp beaks into the tissue, suck up the
sap. These give birth to living larvae which grow very rapidly, and in
turn (though virgin females) bring forth fresh broods of live larvae
that in the course of several generations develop two pairs of large
transparent wings, and consist usually of both sexes, though in some
species the males are wanting. The last generation fly away in swarms
but before dying deposit eggs which carry on the cycle of their life
into the next summer.
The wingless forms are short, stout, rounded creatures with small,
slightly lobed heads, and rather stout 3 to 7 jointed antennae; the
legs are well-developed with two-jointed feet. The abdomen often
swells out into a flask-like shape; it is furnished on the 5th segment
with a pair of cylindrical tubes called siphons, through which it
discharges a sweet secretion known as “honey dew”; this liquid is often
ejected in such quantities on aphis-infested plants that it covers the
foliage, and attracts the ants, which come and lick up the globules of
honey-dew on the tips of the siphons, and even caress the aphis with
their antennae; and therefore in popular works these insects are often
described as “ants’ cows.”
[Illustration: =Fig. 163.=--_Siphonophora rosae_
(Linn.).
The Rose Aphis of the garden.
1, Rose buds infested with aphis; 2, larva; 3, winged female
aphis.
(“Agricultural Gazette,” N.S.W.)]
[Illustration: =Fig. 164.=--_Aphis persicae-niger_
(Smith).
The American Peach Aphis (introduced).
(“Agricultural Gazette,” N.S.W.)]
Among the introduced species common in Australia is the Cabbage Aphis,
_Aphis brassicae_, a dull green insect covered with a floury exudation;
it is one of the greatest pests that the cabbage-growers have to deal
with, and is always most troublesome in dry weather. The Rose Aphis,
_Siphonophora rosae_, is a pale green species appearing in the spring
on the young buds of the roses, but seldom doing very serious damage.
The Woolly Aphis, _Schizoneura lanigera_, common both on the roots and
branches of apple trees, is found in most of our old orchards; the dull
blue aphids cluster together in colonies with their beaks buried deeply
in the bark, and the clusters become covered with a mass of soft white
flocculent exudation, hiding them from view. From the irritation to
the plant tissue caused by their presence large galls or excrescences
appear all over the branches. The Peach Aphis, _A. persicae-niger_, is
another common orchard pest which winters on the roots of the peach
trees: in early summer they commence to spread, and if neglected do a
great deal of damage to the leaf and flower buds.
The chief work dealing with the systematic classification of plant lice
is Buckton’s “Monograph of the British Aphidae,” published by the Roy.
Society, London 1881. A number of new species have been described since
by American entomologists in bulletins on Economic Zoology.
Family 8. Snow-Flies.
ALEURODIDAE.
These are all very small delicate creatures; both sexes are furnished
with two pairs of broad rounded wings with simple parallel veins, and
are usually thickly covered with a mealy white dust from which they
take their popular name of “Snow-Flies.” The head is broad, furnished
with a three-jointed beak enclosing setae; seven-jointed antennae; and
large reniform eyes, with an ocellus on either side above the eyes.
The thorax is broad and the abdomen soft and rounded. The tarsi are
two-jointed terminating in two claws at the extremities.
The female lays her eggs in clusters on the under surface of the
leaves, where the young larvae later on form regular oval, glassy tests
of various colours, enclosed in which they feed and finally pupate.
The adult insects have their short broad wings slightly expanded,
and cluster together in threes and fours: but the moment their food
plant is touched they fly out in a little cloud. They can, like the
scale insects, be very easily introduced into a new country with their
food plant, and several species, like _Aleurodes vaporariorum_
described by Westwood from Europe, have a wide range over America and
this continent.
The snow-flies are well represented in Australia, and several species
do a considerable amount of damage to native shrubs, but on account
of their delicate structure and small size they are difficult to
collect, and harder to preserve when collected; if mounted on card
they dry up, with nothing to determine them from but the wings, which
have very few distinctive characters. The most satisfactory method of
preserving them, is to drop the live insects into oil of cloves on
a micro slip, when they usually open their wings and legs, and then
make, with a little care, very fine objects when mounted in balsam; at
times, however, the floury covering floats off the wings and body and
sometimes clouds the mount.
Maskell has described 8 species from Australia (Trans. N. Zealand Inst.
1896); most of these descriptions, however, were based upon the larval
tests or scales (and not the adult insects) which had been sent to him
under the idea that they were scale insects; so that whoever takes up
the study of snow-flies will have to breed them out, to be sure of
the identity of his species. _Aleurodes styphelia_ forms a flattened,
oval, black test fringed with white waxy tubes almost as long as the
encircled larva, scattered about over the leaves of _Styphelia richei_,
a common scrub bush about Sydney. _Aleurodes t-signata_ forms a spiny
black test; and with a second undetermined pale yellow species without
a marginal fringe, is found about Sydney on the foliage of _Acacia
longifolia_. Another species, _A. banksiae_, is found upon both the
honeysuckle (_Banksia_) and the bottle brush (_Callistemon_).
In Maskell’s paper, which is an important contribution to the study of
these small but very interesting insects, he lists 65 known species
belonging to the typical Genus _Aleurodes_; some have since been
described from America, of which a few have been placed in the Genus
_Aleurodicus_, formed by Douglas for those with a distal and basal
branch on both wings.
Family 9. Scale Insects.
COCCIDAE.
These insects take their popular name of scale insects from the habit
that many of the typical species have of protecting themselves, after
they have settled down on their food plant, by forming a shield or
scale over their backs under which they feed and produce their eggs or
living larvae. To form the scale the moulted larval skin, called the
pellicle, becomes a nucleus in the first place, round which exudations
are added until the scale insect ceases growing.
The larvae are pale yellow, pink, or dull-red coloured little
creatures, oval or shield-shape in form, usually fringed round the
margins of the body with fine filaments, which are often long upon
the somewhat thickened irregularly-jointed antennae and form longer
setae upon the tip of the abdomen. They have distinct black eyes,
well-developed legs; the mouth is pointed and beak-like. At this stage
of their existence the sexes do not differ in outward appearance, but
when they attach themselves to their food plant the males and females
of the same species often construct scales of very dissimilar form;
while in others the male scales are simply more elongate than those of
the female.
The male coccid is a delicate fragile little creature, usually
microscopic in size, so that, unless bred out in confinement from
scale-infested foliage, they are seldom seen. He has a well defined
head rounded behind, furnished with moderately long antennae composed
of thickened irregularly-jointed segments fringed and surmounted with
fine filaments. The globular black eyes stand out on the sides of the
head, but the mouth is aborted so that it cannot feed. The thorax,
lobed on the dorsal surface, is furnished with a pair of rounded wings
each with a simple central nervure, but he can fly well in spite of
their delicate structure. The slender legs are simple, terminating in
rudimentary hooks; the elongated abdomen is distinctly segmented and
furnished at the extremity with a pair of long slender white filaments.
This period of his existence is short: thousands of them perish very
soon after they leave their scale, and the survivors as soon as they
have impregnated the female die.
The female coccid as soon as she settles down to suck up the sap
develops under her protective shield (which, unlike the male, she never
leaves) into an oval or rounded yellow mass: her legs, antennae, and
even head become aborted though the segments of the abdomen are well
defined in most species, and finally she becomes simply a sack of eggs.
She deposits her eggs under the protection of the shield, in other
cases the larvae develop within her shrunken dead skin.
The larvae swarm out and spread over plants when, owing to their
immense numbers sucking up the sap with their sharp beaks, they soon
injure the tissue and often kill the food plant. Thus from an economic
point of view the scale insects are one of the most important groups
of the insect-world that man has to deal with, and thousands of pounds
are spent in spraying and fumigating cultivated trees to destroy these
pests. Many species are cosmopolitan in their range and choice of food
plants, having been introduced all over the world, but Australia has a
great number of indigenous species, many remarkable for their curious
habits, particularly those forming solid woody galls on the eucalypts.
The classification of the scale insects is based chiefly upon the
structure of the adult female coccid, viz.:--Of the spinnerets,
abdominal cleft, lobes, spines, and anal ring of the abdomen, and the
structure and number of joints of the antennae. The shape and structure
of the puparium or scale, or other secretions are used to separate them
into the larger sub-divisions.
The greater number of our species were described by Maskell in
the “Transactions of the New Zealand Institute between the years
1878–1898,” in which period he added over 100 new species to our list:
Green (Pro. Linn. Soc. N.S.W. 1900) has described some others; and
in the same Journal (1882–1898) I dealt with the gall-making coccids
belonging to the sub-family BRACHYSCELINAE. In 1894 Maskell
issued a “Synoptical List of the Coccidae reported from Australia and
the Pacific Islands,” in which 180 species were credited to Australia.
To this Maskell added later a number of new forms; and Fuller others
from Western Australia (Trans. Ent. Soc. London 1899). In Mrs.
Fernald’s “Catalogue of the Coccidae of the World” (Hatch Experiment
Station Bulletin 88, 1903) over 328 species are listed, from this
country, but there are a considerable number of doubtful species among
them.
The COCCIDAE have been divided into a number of sub-families: I follow
Green (Coccidae of Ceylon, 1896), though Mrs. Fernald in following
Cockerell reverses the families and starts with the mealy bugs; I also
retain most of the well-known generic names unless there is a very
valid reason for discarding them, which does not appear to be the case
in many of Cockerell’s amendments.
The Sub-family DIASPINAE are known as armoured scales and embrace most
of the forms which cover themselves with stout horny shields (puparia).
When adult the female is almost legless, with rudimentary antennae,
and incapable of movement. The members of the Genus _Aspidiotus_ form
round scales, and among them are some of our worst orchard pests.
The introduced species _Aspidiotus auranti_, the Red scale of citrus
trees, is now found on many garden shrubs. The puparium of the adult
female is dull reddish yellow with the centre lighter coloured, and
the twigs, leaves and fruit of neglected trees are often covered with
these scales in all stages of growth. _A. perniciosus_, the notorious
San José Scale, that attacks deciduous fruit-trees in the same manner,
is a dull brown circular scale; its original home is somewhat doubtful,
and though it was first recorded as a pest in California, is said to
have come from China. The scales are much darker than those of the red
scale, and infest the branches and twigs so thickly that they destroy
the bark, and whenever they attach themselves to the fruit produce a
red spot. _A. hederi_ (better known under the name of _A. nerii_), is a
pure white scale with a yellow centre; it has a world-wide range, and
its range extends far out into our western scrubs, sometimes covering
the whole of a large tree. _A. rossi_ is a very distinct, round, black
scale, partial to _Euonymus_ in the garden, and to grass trees in the
bush. _A. ficus_ is often known as the “Round Scale” from its size and
regular shape; it is deep chocolate brown in colour, common upon palms,
and is sometimes found upon oranges coming from the Pacific Islands.
_Fiorinia acaciae_ covers the stems and twigs of _Acacia longifolia_
with its narrow white ribbed scale; it is much longer than broad,
and is truncate at the extremities; this gives it a very distinctive
character.
The Genus _Diaspis_ contains a number of delicate, more elongated
scales, among which is the well known white rose scale _Diaspis rosae_,
common in the garden. _Poliaspis exocarpi_ is another white scale
infesting _Oxylobium_, _Dillwynia_, and other bush shrubs; the male
scales are long, slender, and loosely attached to the smaller twigs.
The Genus _Chionaspis_, containing a number of cosmopolitan and
indigenous species, has the base of the scale narrow, elongate, but
broadly rounded at the extremity. _Chionaspis xerotides_ is white,
common upon the blades of the sedge growing along the sea shore at
Botany, N.S.W., and has a wide range. _C. eugeniae_ is a larger broader
scale, variable in size and shape; it infests several native shrubs,
and a very large form is found on the waratah.
_Mytilaspis_ is another world-wide genus, in which the scales are
attenuated at the base and are oyster-like in shape; _Mytilaspis
pomorum_ is the common “Mussel” or “Oyster” scale of the apple tree
found all over the world. _M. spinifera_ is a handsome, broad, white
scale common on the weeping myall (_Acacia pendula_), growing in the
interior. _M. striata_ is a very slender form of scale that has had
to adapt its shape to the slender foliage of the Casuarina which it
infests. _M. acaciae_ is a grey species that clusters thickly together
in masses like the apple scale, covering the stems of several different
species of Acacias in the bush with its stout irregular scales.
[Illustration: Plate XXXIV.--HOMOPTERA.
Family =Coccidae=.
1. _Apiomorpha urnalis_ (Tepper).
2. _Frenchia semiocculta_ (Mask.).
4. _Frenchia casuarinae_ (Mask.).
3. Galls of Buprestid beetles (_Ethon corpulentum_,
Bohem.).]
[Illustration: _Plate XXXIV.--HOMOPTERA._]
In the Sub-family LECANIINAE the female coccids are active or
stationary; naked or covered with some secretion; sometimes without
legs; the abdomen marked with a median cleft and furnished with two
dorsal lobes. Several species of the tropical Genus _Ceroplastes_ are
found about Sydney, where they were introduced into the gardens at a
very early date, and have since spread into the orchards and bush. The
Indian wax-scale, _Ceroplastes ceriferus_, covers orchard trees, and
bush and garden shrubs with its irregular rounded masses of greasy
white matter that protect the liver-coloured coccids beneath. _C.
rubens_ is a smaller and more regularly rounded dull red scale, the
enveloping material forming a hard waxy shell.
The members of the Genus _Ctenochiton_ are chiefly confined to New
Zealand, but two fine species have been described from Australia.
_Ctenochiton eucalypti_ comes from the Newcastle district, N.S.W.,
where it infests the leaves of gum saplings. The scales of the sexes
differ very much; those of the male are slender, white, and glassy,
while those of the female are broad and dark coloured. _C. rhizophorae_
comes from Queensland, where it is found upon the mangrove. The
beautiful, brittle, glass-like scales of _Inglisia foraminifer_ and _I.
fossilis_, are often very plentiful in the interior on low scrub trees.
[Illustration: =Figs. 165= and =166=.--Scale
Insects.
165. _Icerya purchasi_ (Maskell).
The Cottony-cushion or Fluted Scale of the orange tree.
166. _Ceroplastus ceriferus_ (Anderson).
The introduced Indian Wax Scale of citrus trees, etc.]