miners; and several species are well known pests to the gardener.
_Phytomyza affinis_ breeds in the winter in the leaves of the sow
thistle; the next generation swarm on the marguerites, sunflowers and
many others of the _Compositae_, thereby causing them to wither and
fall.
The SAPROMYZIDAE contain a great number of small flies which are
generally met with resting among the foliage when sweeping or beating
the scrub in the early morning. They seldom have the wings spotted,
and the abdomen is broader than that of the former group. The larvae
feed under the bark of trees, or among decaying vegetation. _Sapromyza
fuscicornis_ is of a uniform pale brownish yellow, with dark eyes, and
with scattered stout bristles on the thorax; it is a large species over
¼ of an inch in length to the tip of the closed wings. It has a wide
range over Australia. _S. decora_ is a very much smaller dark brown
fly, with a fine white stripe on each side of the thorax extending
across the sides of the head above the eyes. It is common in summer in
the orchards among the orange trees.
In the members of the Genus _Celyphus_ the scutellum is so abnormally
inflated that it covers all the posterior parts of the body, so that
these tiny shining black creatures are quite unlike the typical
Diptera. A dark brown fly about the size of a house fly that has been
described under the name of _Batrachomyia nigritarsis_ by Skuse, is
a parasite in the larval state on the back of several of our common
frogs, where feeding under the skin it forms a regular blister; when
full grown the larva makes its way through the skin, and pupates in the
damp soil.
The SCATOPHAGIDAE are slender, elongate, medium sized flies that can be
bred out of dung or decaying vegetable matter, and are found in most
parts of the world. _Scatophaga guerini_ measures over ⅓ of an inch
in length; it is of a dull greyish brown tint, marked on the head and
thorax with parallel whitish bars, thickly clothed on the stout legs
with fine hairs; and the long wings are folded over the back when at
rest. It has a wide range; I have it from Sydney, and have bred it from
the cylindrical white maggots in “toad-stools” collected on the banks
of the Darling River, N.S. Wales.
The Genus _Nerius_ (placed by Van der Wulp in the Sub-family
CALOBATINAE, following the SCIOMYZINAE) is represented by two fine
species common in North Queensland. They are very slender, long-legged
flies, with long, straight-veined wings, rounded at the extremities,
and folded over the narrow pointed abdomen; the head, which has a
distinct neck, might be described as pear-shaped, with short, stout,
lance-shaped antennae standing out in front, and elongate flattened
eyes with a dorsal depression between them; the abdomen is elongate,
oval; and both species, about the same size, measure ½ an inch in
length. _Nerius inermis_, “the Banana-stalk Fly,” is of a uniform dull
brown colour, with the dorsal surface of the head and thorax striped
with white, and the whole of the under surface and thighs (except a
brown comma-like mark on the sides) white. The slender white maggots
feed in the ends of the decaying stalks of the bunches of Queensland
bananas, forming elongate reddish brown chrysalids when they pupate;
they are easily bred out in captivity. This species was originally
described from the Nicobar Islands by Schiner; and has also been
recorded from Celebes and Aroe. _N. lineolatus_, described by Wiedemann
from Java, is common in North Queensland; it differs from the last
species in having the dorsal surface more thickly and brightly striped
with white, and the legs being barred with white.
Family 17. Anthomyia Flies.
ANTHOMYIDAE.
In general appearance they are very like the house fly, of small size
and indefinite colour; they differ in the structure of the wings, and
the eyes of the male are generally large and in contact; the antennae
are bare or feathered. In their larval habits they vary very much: some
are simply scavengers; others feed on living vegetation, and like the
onion and cabbage flies are serious pests; and a few are parasitic. The
family is a large one, and species are found in most parts of the world.
The common bluish fly resting on the decaying weed, and flying along
in front when one is walking along the sea shore, belongs to the Genus
_Lispe_; it looks like a house fly with longish legs and a pale tint.
_Ophyra analis_ is a very common inland fly, and may be found swarming
round dead sheep, or bred from pupae found under carrion lying in the
bush. It is a shining blue black fly about the size of an ordinary
house fly, and is lightly clothed with bristles on the sides of the
thorax; it has a somewhat heart-shaped body, and clear wings. A
second species, _O. nigra_, originally described by Wiedemann from
China, is found in Australia, and is also recorded by Walker from the
East Indies. It may be found swarming about dead sheep in summer.
_Phoania personata_ might be taken for a large house fly from the
regular stripes on the thorax, but it is more thickly clothed with
bristles, and the abdomen has a deep metallic blue tint. I have bred
numbers from larvae pupating in rotting oranges piled on the ground.
_Limnophora ruficoxis_ is a somewhat smaller fly with the dorsal
surface of the thorax and abdomen clothed with a dull buff pubescence;
and the scutellum is smooth and shining. I have specimens from Sydney,
N.S.W., and Gatton, Queensland.
Family 18. Parasite Flies.
TACHINIDAE.
This is one of the most useful groups of flies to the agriculturist,
for nearly all the members deposit their eggs upon the living larvae of
other insects such as the plant-destroying cut-worms, many different
moths, and the grubs of our large saw-flies, and immature grasshoppers.
This is a family of considerable extent, for over 1,000 species have
been described from America alone, and in Van der Wulp’s Catalogue 187
species are listed from South Asia, but very little has been done in
working up the Australian species.
In general appearance they are not unlike large house flies, but more
bristly; the bristle of the third antennal joint is bare; the posterior
cell of the wing almost or quite closed, and the large squamae cover
the halteres. They attach their white eggs to the surface of the
caterpillar with a gummy secretion, and it is quite common in summer
time to find caterpillars thus infested, the perfect flies generally
emerging from the pupal shell of their victim.
The members of the Genus _Winthemia_ are rather large flies, parasitic
upon the larvae of different moths; several American species are great
checks upon the increase of the “Army worm” (_Leucania unipuncta_).
_Winthemia lata_ measures slightly under ½ an inch in length, and
is thickset in proportion; it has a silvery face, with the brownish
thorax covered with short stout bristles on the sides; the abdomen
is black, with the sides and outer margin of the segments blotched
with dull yellow; and the whole upper surface is lightly clothed with
fine bristles. I have bred this fly from our Native Silkworm Moth
(_Antheroea eucalypti_), from Lewin’s Moth (_Ocinaria lewinae_), and
from an undetermined hawkmoth.
The Genus _Miltogramma_ comprises a number of smaller flies common in
Europe, which lay their eggs upon the captured prey of the sand wasps
while the latter are placing them in their burrows in the ground; and
not only does the parasitic fly larva devour the food supply, but also
when that is finished, feeds on the baby wasp. An Indian species is
parasitic upon one of the large plague locusts. I have a very handsome
undetermined species from Southern Queensland which has the abdomen
ringed with bright yellow bands; this would suggest that it may deposit
its eggs in the underground chambers of a similarly banded _Bembex_.
Another much smaller species, not unlike the house fly in size and
general colouration, has the grey abdomen barred with black.
Family 19. Metallic Green Flies.
DEXIIDAE.
These flies differ from the Tachinidae, which they otherwise resemble,
in having longer legs, and the bristle of the antennae pubescent or
plumose. Australia is rich in large handsome species, often brightly
marked with metallic tints; they are usually most plentiful in open
forest country, often resting on tree trunks; when flying round they
make a loud humming sound. Most of them are parasitic in their habits,
depositing their eggs upon the larvae of lamellicorn beetles that are
buried in the ground.
_Chaetogaster violacea_ is of the usual thickset form, with a broad
body and long pointed wings; it measures nearly 1 inch from the front
of the head to the tips of the folded wings. It is of a general dark
metallic blue colour, with the dorsal surface of the head and thorax
marked with grey, and the whole insect is clothed with scattered black
bristles. The wings are clouded with dull yellow on the basal half,
giving it a very distinctive appearance. _Amphibolia fulvipes_ is
another very handsome and smaller fly with a broader body than the
last, but the wings are shorter and clouded at the base; the head and
legs are yellow; the rest black, with the thorax spotted behind and
marked with a row of short broken parallel bars in front; the greater
part of the abdomen above and below is creamy white mottled with seven
bilobed blotches of black forming a pattern on the dorsal surface. It
is found about Sydney and has a wide range on the eastern coast.
_Amenia leonina_ is about ½ an inch in length with a more rounded
abdomen. The large head is bright yellow, with the thorax and abdomen
rich metallic blue; the sides of the thorax and abdomen are marked with
several white circular dots, the last two on the tip of the abdomen
very distinct. It is found in Tasmania, and ranges along the eastern
coast of the mainland into Queensland.
The typical Genus _Rutilia_ is well represented in Australia by a
number of large, showy flies rich in metallic tints, and as a general
rule not so thickly or coarsely clothed with bristles. _Rutilia
formosa_, originally described from New Holland by Desvoidy, is not
uncommon along the eastern coast in the summer months. It measures from
¾ to 1 inch in length; is of a general rich light metallic blue tint;
the abdomen indistinctly barred with black is rich metallic coppery
red, duller in the larger females, which have the abdominal segments
more hirsute and bristly. The larvae are parasitic upon beetle grubs,
probably those of the brown cockchafer (_Anoplognathus_). _R. decora_
is about the same size and has much the same habits and range. The
thorax is rich metallic blue, darker in front, with a row of short
black bars; the abdomen is black with a double row of bright green
metallic spots down the centre, the two at the anal tip largest. _R.
vivipara_ measures about 1 inch in length, with a wing expanse of 1½
inches; it is of a general dull greyish brown tint; the abdomen is
lighter brown, and has a dark line down the centre and the sides and
tips lightly clothed with grey hairs. _R. inornata_, about the same
size as the last species, is a much darker fly; the abdomen is of a
uniform dull shining black with grey hairs on the sides but none on the
tip. Both these species have an extended range in forest country.
_Myocera longipes_ has the general colouration of a house fly, with
long, clear wings behind which are large white squamae; and it has very
long slender legs. It has a curious habit of resting on the tree trunks
with its long legs spread out in a very characteristic manner.
[Illustration: Plate XXIX.--DIPTERA.
Family MUSCIDAE.
1. _Lucilia tasmaniensis_ (Macquart). Large blue-bottle
fly.
2. _Lucilia caesar_ (Linn.). Introduced sheep fly.
3. _Lucilia sericata_ (Meigen). Metallic blue-bottle fly.
4. _Musca domestica_ (Linn.). Common house fly.
5. _Musca corvina_ (Fabr.). Bush fly.]
[Illustration: _Plate XXIX.--DIPTERA._]
Family 20. Flesh Flies.
SARCOPHAGIDAE.
These flies differ from the true house flies in having the bristle
of the antennae plumose at the base but fine and hair-like at the
extremity. They lay their eggs or living larvae upon meat or other
exposed food, and are also known as “Scavenger” flies because they
frequent evil-smelling places like pig-sties and slaughter-yards. Some
species are known to deposit their larvae in the nostrils of animals,
and there are several records of the death of human beings from
infestation by these maggots.
The typical Genus _Sarcophaga_ is world-wide in its distribution, and
contains a number of well known species. _Sarcophaga aurifrons_ is
our commonest species in Australia, and is also found in the Malay
Archipelago. It is over ⅓ of an inch in length; the front of the head
is golden; the large eyes deep red; the legs black; and the thorax
and abdomen black but thickly clothed with silvery grey pubescence;
the black shows through, forming three black bands on the front of
the thorax; and the abdomen is mottled with indistinct spots. _S.
frontalis_ is a slightly larger species with the face very bright
golden yellow; the black bars on the thorax finer and darker; and the
abdomen mottled with a more irregular pattern. A much smaller species,
hardly larger than a house fly, was described by Skuse (Agricultural
Gazette N.S.W. 1891, p. 251) as a parasite of the plague locust; he
named it _Masicera pachytyli_; this fly Mr. Coquillett says belongs
to the Genus _Sarcophaga_. I have since bred a much larger species
from the bodies of locusts in the Bombala district, N.S.W. _Tachina
oedipoda_, described by Olliff (Agr. Gaz. N.S.W. 1891, p. 769), I am
also informed by Mr. Coquillett, should be _Sarcophaga oedipoda_, and
is closely allied to _S. aurifrons_: it also is a parasite on the same
species of locust.
Family 21. House Flies.
MUSCIDAE.
This group comprises all the typical house flies, some of which are
world-wide in their distribution. All of them have the bristle that
forms the tip of the antennae hairy or plumose, while the abdomen is
spineless, without bristles except at the extremity.
They deposit their eggs in stable manure or other decaying matter; the
maggots, developing very rapidly in warm weather, form the usual hard
parchment-like chrysalids from which the perfect flies emerge. Many
interesting observations have been lately made on the habits of house
flies and the danger of their spreading diseases by carrying germs or
particles of putrid matter upon their feet, and thus contaminating
food or transferring germs into open wounds; it was proved in the
Spanish-American war that the swarms of flies had a great deal to
do with the spread of fever in this manner. _Musca domestica_, the
common house fly, is almost world-wide in its distribution, and is the
chief species found inside the house. In the larval state it chiefly
develops in stable manure. It measures about ¼ of an inch in length; is
of a uniform black tint but is so thickly clothed with grey tomentum
that it appears to be brown; the eyes are red; the thorax is clothed
with stiff black bristles, and has four parallel bars down the centre
of the dorsal surface. The freshly deposited eggs hatch within a day
or two; the maggots develop within six days, and remain in the pupal
state for only a few days in the summer; so that it is no wonder that
they multiply with such marvellous rapidity, particularly when we
discover that one house fly will lay over 1,000 eggs in the season.
_Musca corvina_ is a smaller darker tinted species, showing only two
parallel stripes down the thorax. It is a common bush species and a
great pest in the bush all through the summer, swarming in countless
thousands from the eastern coast into the interior. It has a wide
range over Europe, North America, Ceylon, and the Malay Archipelago.
_Stomoxys calcitrans_ is of a more brownish tint, with the abdomen more
flattened, and it differs from the last two species in having a well
developed biting mouth; this fly is a troublesome pest to horses, and
will alight on one’s hand and bite quite sharply. It has a wide range
from Europe across Asia to Ceylon, Java, and Australia.
The Genus _Calliphora_ is well represented by several very distinct
species of typical “Blow-flies”; but though the common European
species, _Calliphora vomitaria_, is said to be common in New Zealand
I have never taken it in Australia. _C. villosa_ is our large common
blow-fly; it measures about ½ an inch in length; is of a general
slate grey colour with the abdomen thickly clothed with fine golden
pubescence giving it a bright mottled yellow tint. _C. oceaniae_ is the
smaller blow-fly with a steely blue abdomen, the base on either side
bearing a dull yellow blotch by which it can be easily distinguished.
Both these species are found in the bush and in the house; they lay
their eggs on any food they can gain access to; but in the summer, or
when they cannot get at food in time, the egg is hatched in the body of
the mother and dropped as a living maggot. Some of the bright metallic
species also come in this Genus; _C. rufifaces_ is a much smaller
bright rich metallic blue fly, with a silvery face, red eyes, and white
flaps behind the wings; it, and the much smaller _C. varipes_ with a
yellow face and darker tinted body, are common about dead sheep or
decaying matter in the interior.
[Illustration: Plate XXX.--DIPTERA.
Family MUSCIDAE.
1. _Calliphora oceaniae_ (Desv.). Blue-bodied blow-fly.
2. _Calliphora oceaniae_ (Desv.). Maggot.
3. Head segment of maggot, showing mouth hooks.
4. Anal segment of maggot, showing tubercles.
5. Pupa.
6. _Calliphora villosa_ (Desv.). Yellow blow-fly.]
[Illustration: _Plate XXX.--DIPTERA._]
_Neocalliphora ochracea_ is somewhat thicker and broader than
_Calliphora villosa_, and a much rarer species; it is of a general dull
reddish brown colour, with the head and thorax darkest.
In the Genus _Lucilia_ we have the typical “Bluebottle” flies, which
are well represented in this country: _Lucilia sericata_ and _L.
caesar_, both of a moderate size and deep metallic green and coppery
tints, are widely distributed. _L. tasmaniensis_ is a larger species,
measuring under ½ an inch in length; it is of a uniform bright metallic
blue, and has a wide range.
Family 22. Bot-flies.
OESTRIDAE.
The members of this family are well known in most parts of the world
in the larval state as “bots,” internal parasites in the stomach of
the horse, in the nostrils of sheep, and the skins of cattle. The
life history of the common European bot-fly, _Gastrophilus equi_, is
well known; the active fly lays her eggs upon the shoulders or jaws
of the horse, attaching them to the hair by a gummy secretion; the
horse licking itself transfers the eggs into its mouth, where the
tiny maggots hatch out and are carried down into the stomach. They
are provided with a pair of fine curved hooks in front of the head by
which these little creatures hook themselves into the membrane of the
stomach, absorbing their nutriment from the liquid with which they
are surrounded. When fully developed these oval spiny bots detach
themselves and pass out with the excrement, the maggots at once burying
themselves in the damp soil and pupating; the perfect fly emerges early
in February in most parts of N.S. Wales. The flies, about ½ an inch in
length, have large thickset bodies thickly clothed with short brown
or golden hairs, giving them the general appearance of a hairy bee;
the male has a short rounded abdomen; that of the female is greatly
elongated and usually curled up underneath. There are probably several
introduced species now common in Australia with a wide range over the
country. It is remarkable that though they do not bite or sting the
horses when laying their eggs, yet as soon as the horses hear the loud
hum of the bot-fly they gallop about and show an inherited fear of this
pest, which, though it does not kill them, must be a very unpleasant
parasite when numerous. The members of the Genus _Hypoderma_ are a very
serious pest in Europe and other countries where they infest cattle,
and are known both as “warble” or “bot-flies.” The fly lays her eggs
upon the back of the beast; the tiny larva makes its way through the
hide, beneath which it lives and feeds upon the putrid matter caused
by the irritation of its presence; it finally produces an inflamed
blister-like swelling or “warble,” eventually working its way out
through the hide and falling to the ground, where it buries itself and
pupates. No species have been found in Australia, but in some parts of
England very serious damage is caused to the health of the beast, and
the skin by being perforated loses value for making leather.
[Illustration: =Fig. 151.=--_Gastrophilus equi_
(Fabr.).
1 and 2, The introduced Bot-fly, showing dorsal and lateral
view of female; 3, eggs attached to hairs of horse; 4, egg
enlarged (the eggs should be more truncate at the tips); 5,
larval bots attached to piece of the stomach of a horse; 6,
bot much enlarged; 7, enlarged head of bot showing the mouth
hooks.]
The Sheep Nostril Fly, _Oestrus ovis_, has a wide range over the
world, and was probably introduced into Australia many years ago,
though it has been noticed only quite recently as a serious pest.
This fly lays living maggots in the nostril of the unfortunate sheep;
the maggots work their way up into the frontal sinuses of the head,
where they remain until fully developed, when they turn downward and
are usually sneezed out by the sheep in their efforts to get rid of
the obstruction. The fly is slightly under ½ an inch in length; the
upper surface of the head and body are grey to dull yellow, spotted or
mottled with darker tints; the abdomen is yellowish mottled with darker
markings. It has been found chiefly in the Blue Mountains N.S.W.
Family 23. Louse or Spider Flies.
HIPPOBOSCIDAE.
These are parasitic Diptera, that having taken to idle and slothful
habits (though some of them can fly very well), take up their quarters
among the fur or feathers of different animals and birds, where they
live and are carried about by their hosts. To suit this method of
existence they have become quite altered in structure; they have flat
leathery bodies, and their feet are produced into large pincer-like
claws which enable them to cling to the skin of their host. Some have
large wings with stout nervures but very rudimentary venation; a few
though provided with wings at birth bite them off soon after; and
others like the well known “sheep tick” are wingless.
As a rule their presence even when numerous does not seem to incommode
the infested animals after they have become used to them, for the
wild ponies in the New Forest in England are often covered with the
horse-fly, _Hippobosca equi_, and they take no notice of them. Yet
if one alights upon a horse unaccustomed to the presence of the fly
he becomes almost crazy with fright, probably from the pinching or
tickling sensation produced by their claws.
[Illustration: =Fig. 152.=--_Ortholfersia macleayi_
(Leach).
A parasitic fly that lives upon wallabies. Figured by me
as _Olfersia macleayi_ (Leach) in the “Agricultural
Gazette,” N.S.W.]
The Common European Sheep Tick, _Melophagus ovinus_, was introduced
at a very early date into this country among the wool on the backs
of sheep. It is a dark-brown, wingless creature thickly clothed with
fine hairs, more like a stout-legged spider than a fly in general
appearance, but it has not the requisite fourth pair of legs. These
bristly legs are furnished with the usual stout curved claws, between
which is a slender appendage like a short string, supposed to be used
to hang on with by coiling it round the wool. From their blood-sucking
habits and these pincer-like claws, they are very annoying to the sheep
when numerous.
The Wallaby Louse Fly, _Olfersia macleayi_, is very common on small
marsupials in Australia and Tasmania. When the dogs while hunting pull
down and kill a wallaby, these flies generally crawl off and cling
to the dog’s nose, rendering him very unhappy. It is a winged form,
measuring under ½ an inch to the tip of the folded wings, and is of a
uniform shining dark brown tint with a greenish shade very noticeable
in the legs. Speiser (Annals Musei Nationalis Hungarici 1904) has
placed this species in his Genus _Ortholfersia_.