Chapter VI: Introduction (4)

These are commonly known as Ichneumon Flies, and the family is a very extensive one. They play an important part in the economy of Nature in destroying thousands of the moth and other larvae that would otherwise strip our fields and forests of their grass and foliage, and they are therefore useful allies to the agriculturist; though they also often destroy other beneficial insects as well as pests, and thus discount their usefulness. Ichneumon Flies are moderately sized insects furnished with long slender antennae composed of from 16 to upward of 60 joints, with the basal one often thickened, but never elbowed. The wings are well developed, with a distinct stigma and numerous nervures forming regular cells; a few species are wingless in both sexes, but these exceptional ones have not been recorded from this country. The legs are long, generally slender, and well adapted for running about; the abdomen is usually long, rounded or cylindrical, joined to the thorax on the under side, and more or less stalked, while the ovipositor of the female is characteristic of the group and adapted or modified for laying the eggs in or upon the different hosts they prefer to adopt for their offspring; when they infest wood boring caterpillars that are somewhat out of reach, the ovipositor is correspondingly long and the sheath and “tails” produced so as to guide the eggs to their resting place on the grub, out of the sight of the parent ichneumon. When the species lays its eggs on the back of leaf-eating insects with no protective covering, the ovipositor is generally short and stout, the tip sometimes so stiff and sharp, that several species are credited with stinging people when handled. The little wasp-grub, hatching from the egg either deposited on the back or placed beneath the skin, feeds upon the substance of the body of its victim without touching the vital organs, so that in most instances where the caterpillar of a moth is infested, it yet has the power to form its cocoon and pupate before the wasp-grub has finished growing; the latter thus finishes its final transformation in the destroyed moth pupa, and cuts its way out through the side of the cocoon when ready to emerge. Usually, if it is a large species, the ichneumon deposits only one egg in its victim, but in some of the smaller ones half a dozen can be bred from a single cocoon. Over 6,000 species of these insects have been described from all parts of the world, and in many countries, such as this, the native species are still hardly known, and much confusion exists in their classification on account of their parasitic habits and the number of different hosts that the same species may infest; but now that so many economic entomologists are at work all over the world, it will probably not be long before they will have many admirers, and a rich field awaits the entomologist who takes up the study of Australian ichneumons.

Cresson in his “Synopsis of the North American Hymenoptera” lists over 1,100 described species, while in Australia up to the time when Brullé published his “Histoire Naturelle des Insectes, Hymenopteres,” in 1846, only one or two had been described, to which he added eighteen species; Kirby, Smith, Cameron and several foreign entomologists have added a few more; and in Ashmead’s recent paper ten more Australian species are described, which makes a very meagre list.

The Spotted Black Ichneumon, _Pimpla intricatoria_, is one of our largest common species, having a wide distribution over Australia, and it breeds in a number of different moths. It measures nearly 1 inch in length to the tip of the short ovipositor, and is of a uniform black colour with red legs and antennae; the thorax and abdomen are ornamented with pale yellow spots, those on the latter oval, forming a row on either side.

The Dark-winged Ichneumon, _Rhyssa semipunctata_, is a more slender species of about the same length; is of a uniform dull red colour except the basal half of the abdomen, which is black with white markings on the sides; the wings are clouded with brown, darkest on the inner portion. These wasps always follow up the cut worms and caterpillar plagues, and destroy immense numbers in the pupal stage.

The Spotted Ichneumon, _Mesotenus albopictus_, is somewhat smaller, with slender stalked abdomen and the slender ovipositor turned downward: the general colour is black, with the antennae marked with yellow toward the apical portion; the head, thorax and abdomen are richly marked with light yellow; light brown wings and red legs mottled with black and yellow. This ichneumon breeds in a great number of different cocoons, and frequently emerges from the oval cup-like ones of the “Stinging Caterpillars” (_Doratifera_ and _Limacodes_).

The OPHIONINAE comprises a number of genera, of which the typical species are reddish brown insects, with clear wings and curiously curved, laterally flattened bodies, broadest at the extremity. They are frequently noticed in numbers among the low scrub in the day time, and in the summer evenings often fly into the house round the lighted lamp. Six species of the typical Genus _Ophion_ are described from Australia; but none of the Genus _Anomalon_ have been recorded.

=Fig. 50.=--_Bassus laetatorius_ (Fabr.). An
Ichneumon wasp that destroys the pupae of Syrphid flies.

(“Agricultural Gazette,” N.S.W.)]

_Bassus laetatorius_ is a well known Ichneumon which has a very wide range over the globe, and is not a useful species, for it lays its eggs in the larvae of Syrphid flies, which feed upon different kinds of plant lice (_Aphis_) and are very useful insects to the gardener. It measures about ¼ of an inch in length, with the head, thorax, tip and base of the abdomen black, the rest reddish brown with yellow markings on the head. The tibiae of the hind legs are very distinctly banded with white, black, and reddish brown, giving it quite a distinctive character.

Family 9. Small Ichneumons.

BRACONIDAE.

These are insects with very similar habits but easily separated from the large ichneumon wasps by the structure of the fore wings, as they have the outer cross veins wanting, thus showing two long outer cells, which in the former are divided into two cells. The antennae are always composed of more than fifteen joints, and the segments of the abdomen are more soldered together. Many of them, like the _Microgasters_, are very small, others are as large as many of the smaller true ichneumons. This country is probably very rich in indigenous species, while we have a considerable number that have been introduced with their host insect; but hardly anything has been done in describing our species. As far back as 1775 Fabricius named 4 species of the typical Genus _Bracon_, to which only three other species have been added, though over 500 species are listed in Dalla Torre’s Catalogue in the cosmopolitan Genus _Bracon_ from other parts of the globe.

The typical Braconid is usually very small; many of them are no larger than some of the Chalcids. Wherever the cabbage aphis or other plant infesting insects such as caterpillars are to be found, these little wasps can be observed hovering round, waiting for an opportunity to deposit their eggs. They differ from the large ichneumons, in that while the latter only deposit a single, or at most a dozen eggs upon a victim, these often place hundreds in a large caterpillar, which, emerging when full grown, form little white oval silken cocoons on the top of the remains of their hosts, that are sometimes surrounded with a mass of white fibre exactly like cotton wool. After a plague of cut worms has passed over a paddock it is quite common to find clusters of these little cocoons attached to the grass stalks; these have been often sent to me from the country with the information that they were the eggs of the plague caterpillars or cut worms.

=Fig. 51.=--_Ephedrus persicae_ (Froggatt). A
Braconid wasp that lays its eggs on the bodies of aphids.

(“Agricultural Gazette,” N.S.W.)]

_Bracon limbatus_, one of our larger typical species, is found in Tasmania, and has a wide range over Australia. It measures about ½ an inch from the front of the head to the tip of the abdomen, and is of a general black colour on the upper surface, with dusky almost black wings, and a red head. The under-surface is marked with brown, with the thorax, thighs, and tibiae of the front and middle legs black; the three slender curled hair-like tails forming the ovipositor being longer than the whole insect. Eight other species of _Bracon_ are described, several of which are also recorded from New Guinea and New Zealand. Among the introduced species is _Lepolexis rapae_ of Curtis, which is parasitic upon the cabbage aphis in Europe; it can be collected in gardens about Sydney. Aphids containing these parasites are always swollen, round, and apparently dead skins through which each braconid eats its way.

Five species of the Genus _Agathes_ are described; they are remarkable for their showy particoloured wings, and large size in comparison with other members of this family. Ashmead has described a tiny black species marked with yellow bred by me from the larva of a Noctuid Moth, an undetermined species of _Agrotis_, under the name of _Apanteles antipoda_; and a second larger one as _Apanteles australasiae_. In his Genus _Microbracon_ he has described a dainty little black and yellow creature that infests the larvae of our scale-eating moth (_Thalpochares coccophaga_) under the name of _Microbracon thalpocaris_.

Family 10. Ruby Wasps.

CHRYSIDIDAE.

The popular and scientific names of these insects refer to the brilliant metallic blue, green, golden or copper coloured tints of their armour-plated bodies, which are also covered with coarse punctures, finest upon the abdomen. They are stout thickset wasps with short curled antennae and large eyes; the thorax is broad and closely attached to the abdomen, the latter composed of from three to five segments, the first generally much shorter than the second, with the last toothed along the hind margin, and characteristic of the different species; the under-surface of these plates is concave, with the tip of the abdomen produced into a tubular process, so that when alarmed the wasp can curl her body round into a ball, protected on all sides by the armour-like integument; and as she lays her eggs in the nests of other wasps and bees, and is sometimes caught in the act, this habit is probably a wise provision of Nature which enables her to resist the sting of the lawful nest maker.

Some of the earlier observers called them “Cuckoo Wasps,” under the impression that their larvae, when hatched out in the nests of hunting wasps or bees that filled the cells with insects or bee bread, fed upon the stored food supplies, but later researches show that, though the egg of both the lawful occupant and the intruder may be deposited in the cell, the latter does not hatch until the former has devoured all the food placed there by his mother and is ready to pupate; then the ruby wasp baby comes out, attaches itself to the full fed larva beside it, and sucks him dry, pupating in his skin.

Most of our species that I have bred out are parasitic in the clay nests of the smaller Mason Wasps, _Odynerus_ and _Alastor_, though in Europe many species live in the nests of bees. The perfect insects are generally found crawling over or flying round old fences or stumps and dead trees in the hottest part of the day. Our species were described by F. Smith in 1874 in his revision of the family, in the Transactions of the Entomological Society of London; a few others have since been added to the list by Mocsáry, who monographed the Chrysididae in 1889; and Gribodo in the Annals of the Mus. Geneva, 1879.

No member of the typical Genus _Cleptes_ common in Europe and America is recorded from Australia; but two well defined species of the beautiful ruby wasps of the Genus _Stilbum_ that has a world wide range are described, _Stilbum splendidum_ confined to Australia and New Caledonia, and _Stilbum amethystinium_, found also in Asia, Africa and America. The great Genus _Chrysis_, which contains over 600 described species, is represented here by about 27 species.

Family 11. Hatchet-bodied Wasps.

EVANIIDAE.

Under the recent classification of this family it now comprises three very well defined genera, which have moderately thick antennae, not elbowed, consisting of thirteen or fourteen joints; the nervures of the wings not so well defined as those of the Ichneumons; and the stalked abdomen attached to the upper part of the metathorax. They are well represented in this country, and have been chiefly described by Westwood and Schletterer.

Family MEGALYRIDAE.

1. _Megalyra fasciipennis_ (Westwood). ♀.

Family ICHNEUMONIDAE.

2. _Pimpla intricatoria_ (Fabr.). ♀.

Family EVANIIDAE.

3. _Gasteruption sp._

Family MUTILLIDAE.

4. _Mutilla formicaria_ (Westwood). ♀.

Family CHRYSIDIDAE.

5. _Stilbum splendidum_ (Fabr.).

Family THYNNIDAE.

6. _Diamma bicolor_ (Westwood).
10. _Thynnus variabilis_ (Kirby). ♀.
11. _Thynnus variabilis_ (Kirby). ♂.

Family SCOLIIDAE.

7. _Trielus zonata_ (Smith). ♀.
8. _Discolia verticalis_ (Fabr.). ♂.
9. _Discolia soror_ (Smith). ♀.

Family SPHEGIDAE.

12. _Bembex tridentifera_ (Smith).

(Original photo. Burton.)]

The members of the typical Genus _Evania_ are generally shining black insects, sometimes variegated with dull red markings; the head and thorax are short and broad; the abdomen has the first segment produced into a slender stalk, and the remaining ones forming a vertically compressed hatchet-like body. They are parasitic upon the egg cases of cockroaches; some with a very wide range have been introduced in all probability with their cosmopolitan hosts, while they are often found in the house flying on the window panes, evidently introduced in the same manner. In the bush the perfect insects are commonly found on flowering shrubs in the summer time. About 20 species are described from Australia and Tasmania. _Evania princeps_ is of a uniform black colour with dusky wings, and is recorded from most parts of Australia, Woodlark Island and New Guinea. It is one of our largest species, measuring ½ an inch in length, broad in proportion, and furnished with very long spined legs.

The Genus _Gasteruption_, which takes the place of the Genus _Foenus_ in the earlier catalogues, contains 36 described species from Australia; as they are rare insects, there are probably many more to be discovered. Nothing is known about their habits for certain, but they are supposed to be parasitic upon the larvae of wood boring insects; I have generally found them flying round the trunk of a dead or burnt tree. They differ from the former genus in having the head almost globular, with antennae standing out straight in front, and large oval eyes on the sides; the thorax is more elongate, rounded in front, so that the insect appears to have a slight neck. The abdomen springs from a rounded node on the thorax, with the basal segments slender, swelling out gradually, and broadest at the tip; the females bear a very long hair-like ovipositor. The legs are slender, the hind pair longest, with both the thighs and apical half of the tibiae thickened in a very distinctive manner. Ten species are described from Sydney; and one, _Gasteruption pedunculatum_, is also common to New Zealand.

The Genus _Aulacus_ contains ten described species of smaller insects. _Aulacus apicalis_ is parasitic upon the larvae of a longicorn beetle (_Piesarthrius marginellus_). I have found as many as fifty, each enclosed in a thin parchment cocoon, all matted together in a single cavity. This little wasp has a long extended ovipositor, and measures about ½ an inch in length; the head and greater portion of the abdomen is black, the rest reddish brown, with a blotch of yellow on the upper surface of the base of the abdomen; the hyaline wings are tipped with black.

Family 12. Long-tailed Wasps.

MEGALYRIDAE.

These remarkable parasitic wasps, peculiar to Australia, are comprised in a single genus containing 16 species, none of which are very common. They are all shining black insects; the head short, broad and almost rounded, the thorax broad and stout, both very rugose and clothed with fine silvery hairs on the sides; the eyes large, circular, and very prominent; ocelli small; the antennae composed of irregular wiry joints; the wings semitransparent, generally banded with black, and the transverse nervures wanting in the apical half; legs long, with the thighs thickened. The abdomen is closely attached to the thorax, cylindrical, tapering to the extremity, and in the females furnished with an ovipositor often more than three times the whole length of the insect, looking exactly like three black horse-hairs. These elongated ovipositors are used for depositing their eggs in the wood-boring larvae of longicorn beetles belonging to the Genus _Phoracantha_, and probably others of like habits, which feed under the bark in the sap wood of different eucalypts. The perfect insects are generally found about flowers on low shrubs in summer.

_Megalyra shuchardi_ is of the usual black colour with silvery pubescence; the wings are pitch black and opaque: the whole insect measures slightly under 1 inch in length, with the ovipositor over three inches. It is found in Victoria and New South Wales, and also recorded from Melville Island on the North Coast. _Megalyra fasciipennis_ was described by Westwood when he founded the genus, in the Transactions of the Entomological Society 1841; and it is again figured in Griffith’s Animal Kingdom, Insects, Vol. II. It is much smaller than the previous one, of similar form, the legs and ovipositor reddish brown, the wings hyaline, barred across the centre and clouded at the extremities with blackish brown. The male is much smaller than the female, with similar wings, but the body is more slender and comes to a point at the tip, furnished with a curious bifid anal appendage. This is the species we have found breeding from the longicorn larvae.

Six other species have been described, some by Schletterer (Berliner Entom. Zeitschrift 1889); one, _Megalyra melanoptera_, closely allied to Westwood’s dark winged species. In 1902 Szepligeti (Termes Z. Fuzetek, xxv.) monographed the family and added one more; and Bradley last year, describing the last new form (Trans. Ent. Society of London 1905) appends a translation of the former’s tabulation of all the known species, seven in number. I have (Pro. Linn. Soc. N.S.W. 1906) since added 8 new species to the list.

Family 13. Ants.

FORMICIDAE.

The ants are among the first insects that attract one’s notice in a new country; civilization seems to agree with many species which form their nests in the lawns or gardens, and even take up their quarters in the house. Within the last decade a small introduced species has appeared in the heart of London, and the small red ant, _Monomorium pharaonis_, is a world wide pest in houses from Europe to Australia.

Ants live in communities forming nests in the ground, under logs or stones, or in dead trees, and sometimes among the foliage of plants. These communities consist of winged males and females, and wingless aborted females known as workers, the bulk of the family consisting of the latter; in some groups there are several varieties of workers, that are often called soldiers on account of their great size and swollen heads. In those species that are furnished with a sting both the workers and winged females should be handled with care.

They are divided into five sub-families, based on the difference in the structure of the segments of the body, absence or presence of a sting, and a few other minor characters. The leading specialists differ somewhat in the sequence of these groups; I follow Forel in placing the _Ponerinae_ at the head of the family; and for a good classification and definition of the genera would refer my readers to Emery’s paper in the “Annales de la Societe Entomologique de Belgique,” Vol. xl., 1896. All our species described before 1858 are listed in Smith’s British Museum “Catalogue of the Formicidae,” where he described a number of new species: Lowne described a number of new species collected in the neighbourhood of Sydney in the Entomologist, Vol. ii., 1865: Mayr in several papers, chief of which are “Myrmecologische Studien,” “Neue Formiciden,” and “Die Australischen Formiciden” added many up to 1876. Emery, Forel, and others have since added to the list; and in Dalla Torre’s great “Catalogue of the Hymenoptera,” published in 1893, all species described up to that date are recorded. I have lately (1905) published a list of Australian species (Miscellaneous Publications No. 889, Dep. Agr. N.S.W.), including all Forel and others have added to our fauna, in which nearly 400 species are recorded, without counting the large number of races and varieties into which some of them are divided. From my own researches I think a great many more will be found when they are systematically collected in the tropical scrubs and the dry districts in the interior, which as yet have hardly been touched.

* * * * *

The sub-family PONERINAE includes many large or medium sized ants with elongated bodies furnished with only one constricted segment or node at the base of the abdomen, and the latter terminating in a powerful sting. The larvae are enclosed in stout silken cocoons. The Genus _Myrmecia_ contains most of our largest typical species peculiar to Australia, popularly known as “bull-dog ants,” “inchmen,” or “jumpers”; about 34 species have been described, some of which have a very wide range. The “Jumper,” _Myrmecia albo-cincta_, forms its nest under the shelter of a low bush; it is a low mound with an opening on the summit, and another on the side level with the ground; when disturbed these ants come rushing out like a pack of dogs with a series of short jumps, and attack everything they meet. It is one of the smaller species, about ½ an inch in length, of a uniform black colour, with only the front and hind portion of the thorax brownish red to yellow. _Myrmecia forficata_ is our large red and black “bull-dog ant,” with a very extended range like the previous one from Victoria to Queensland. They measure up to 1 inch in length, and are of a uniform dull red, except the eyes and abdomen, which are black. They live in rather large colonies up to 200 in number, digging deep circular shafts or irregular chambers under logs; when away from the latter, they form regular domed mounds over the nests, which in summer contain the large, elongated, oval, brown sacks enclosing the pupae, and often a number of winged males and females; the former with small heads and jaws, the latter with jaws as large or larger than those of the workers. _Myrmecia gulosa_ is of a lighter red colour, with the tip of the abdomen black. _M. tarsata_ is our common black bull-dog ant, with yellow jaws, and antennae and tips of the legs reddish brown; it has a great habit of hunting up and down the larger tree trunks, and drops to the ground at the least alarm; when disturbed in the nest, if the first two or three are captured, the others will usually retreat down their burrows, and not show fight like the other species. Sharp notes the bull-dog as forming large mounds (Cambridge Natural History); but I think he was misinformed, as the nests of the Mound Ant, _Iridomyrmex detectus_, are often confounded with these ants. The Genus _Odontomachus_ contains a number of curious slender black ants with large heads and long projecting jaws; they are more tropical in their range, but _O. ruficeps_ and its varieties are found from the Darling River N.S. Wales through Queensland to North Australia.

The “Green-head,” _Ectatomma metallicum_, is a common ant of medium size that lives in small communities under stones or logs, and often makes nests in the dry banks of lawns in our gardens. Though somewhat sluggish, they sting sharply if they crawl on one when resting on the grass. About 28 species and many varieties of this genus occur in Australia; one in New Zealand; and 3 in New Caledonia. The members of the Genus _Ponera_ are remarkable for their extended range; we have several species or varieties in Queensland closely allied to species from South America, Borneo, Europe, and Africa, while three are recorded from New Zealand; _Euponera lutea_, a slender pale yellow ant with the abdominal segment constricted, lives in small communities under stones or roots. It ranges from Sydney to Fremantle, round to N. Queensland. _Pachycondyla piliventris_ is a large, hairy black ant with large head and rounded body, roughened, and clothed with fine rusty down. They are generally found under stones in communities of a dozen or so, and when exposed or disturbed pretend to be dead, with their legs folded up under the body; they are common about Sydney.

Six species of the Genus _Sphinctomyrmex_ are found chiefly in the North. They are somewhat rare ants; I have found two species, both small, slender, dull brownish yellow insects living under stones; _S. froggatti_ in a vineyard near Sydney; and the second, _S. hednigae_, in the New England district under large stones.

* * * * *

The second sub-family, DORYLINAE, comprises ants with the antennae placed close together in the front of the head, the abdomen elongated, with the first segment forming an irregular node. This group contains some very remarkable ants in Africa and America, but is only represented in Australia by two species belonging to the Genus _Ænictus_, both of which are described from specimens collected by Turner at Mackay, Queensland.

* * * * *

The third sub-family, MYRMICINAE, is well represented here; they are all small or medium sized ants, with the base of the abdomen formed into two small nodes, and the sting rudimentary; the pupa naked and not enclosed in a cocoon. Many of them live in very large communities.

The members of the Genus _Meranoplus_ are tiny little brown ants with rounded heads and bodies, resembling some of the small wingless female Mutillid in shape and habits, for though they form irregular galleries under stones or in dry banks, they are generally found running up and down tree trunks; when touched they curl up the body and sham death. _Meranoplus oceanicus_, reddish brown, is common in N.S. Wales; _M. pubescens_ has a very wide range right round Australia.

* * * * *

_Monomorium pharaonis_ is our tiny red house-ant introduced from Europe, now world wide in its range; and when once it becomes established in a house is a difficult pest to destroy. _M. rubriceps_, a much larger species but under ¼ of an inch in length, is bright reddish brown, with the nodes very small and the apical portion of the abdomen black, and broadly rounded. It is found crawling upon the trunks of trees, and has a wide range from Sydney to Cape York. The typical tree-trunk ants included in the Genus _Podomyrma_ are much larger ants, sluggish in their habits, forming their nests in tree stems and always found crawling about the trunks. They are broad-headed ants with short stout jaws toothed at the tips; the thorax is widest in front, tapering to the narrow pedicle of the broadly rounded abdomen; the thighs of the legs are thickened in the centre. _Podomyrma gratiosa_, under ½ an inch in length, is bright reddish brown, rugose and spined on the front margin of the thorax, with the abdomen black, smooth, and shining; it is widely distributed over Australia from Adelaide to Cape York. _P. adelaidae_ is a smaller species with black legs, and a distinct oval brown blotch on either side of the black abdomen; it is common in South Australia and Victoria. _P. bimaculata_ is still smaller, with the blotches on the abdomen smaller and more oval; I have had it from Kalgoorlie W.A., and Wagga N.S. Wales.

Family FORMICIDAE.

1. _Iridomyrmex detectus_ (Smith).
2. _Polyrhachis semi-aurata_ (Mayr).
3. _Myrmecia gulosa_ (Fabr.).
4. _Ectatomma metallicum_ (Smith).
5. _Iridomyrmex rufoniger_ (Lowne).
6. _Camponotus nigriceps_ (Smith).]

The Genus _Pheidole_ is well represented in Australia by 22 species and many varieties found in all parts of the country, forming irregular chambers and galleries under stones and logs; they are tiny reddish brown ants, with a very large headed form of soldiers often four or five times the size of the ordinary workers. The winged forms are also very large in proportion. _Pheidole bos_ is dark reddish brown, the soldiers furnished with very large swollen heads; it ranges from Western Australia to Victoria. _P. anthracina_ is a darker coloured form, ranging from the northern portion of N.S. Wales into Queensland. The members of the Genus _Cremastogaster_ are very small black, brown, or dull yellow coloured ants with longer legs, and heart-shaped bodies; they live in large communities in nests under logs and stones. _C. fusca_ is black with reddish tarsi, and a reddish tint on the thorax; it comes from Queensland. _C. pallipes_ and _C. ruficeps_ are lighter coloured, found under stones about Sydney.

_Sima laeviceps_ is a very curious elongated shining black ant with reddish brown antennae and tarsi, which ranges up the Queensland coast to N.W. Australia, and is found crawling about on tree trunks, when touched curling its body up like a wasp and shamming death.

* * * * *

The sub-family DOLICHODERINAE comprises a number of small or medium sized ants living often in very large communities and having naked pupae. The base of the abdomen consists of a single small node with no constriction between the two following segments; sting practically wanting (rudimentary). The typical Genus _Dolichoderus_ is represented here by five species widely distributed. _D. doriae_ is common about Sydney living in large communities under logs, often clustered over each other like a swarm of bees; they collect on the leaves of eucalypts, upon which the sugar lerp psylla, (_Spondylaspis eucalypti_) constructs its larval scales, and suck or lick up the sugary exudation. This ant measures ¼ of an inch in length; the head and thorax are black and roughened; the legs reddish brown, and the flattened heart-shaped abdomen clothed with a silvery pubescence. _Leptomyrmex erythrocephalus_ might well be called the “Silly Ant” from the aimless manner in which it rushes about with its head stuck up in the air, and its abdomen curled over its back. They live in underground nests sometimes deep down, but others live under stones; they are slender-bodied, long-legged black ants under ½ an inch in length, with an oval red head, rounded behind with long slender antennae, and the front of the thorax produced into a slender neck. In some varieties the whole of the thorax, legs, and head are yellowish brown.

The typical Genus _Iridomyrmex_ contains 18 distinct species, some of which have been subdivided into three or four varieties or races; most of them are small, except our “Mound Ant,” sometimes known as the “Meat Ant,” _Iridomyrmex detectus_, which is the commonest and most widely distributed ant in Australia. They construct large mounds a couple of feet above the surface of the ground, and two or three yards in diameter; they are formed of the soil excavated from beneath when forming their network of irregular open galleries; the upper surface is pierced with numbers of rounded vertical shafts, up which they swarm in countless thousands and attack any intruder, biting savagely with their stout sharp jaws and making things generally unpleasant for the stranger. When a mound is situated in open grassed country, one can trace regular bare roads leading off from the nest, worn smooth by the regular stream of ants passing backward and forward day after day. It is too well known to need description, but measures about ⅓ of an inch in length, and is of a general brownish purple tint, with the head light reddish brown. Smith described the worker under the name of _Formica purpurea_, and the male as _F. detectus_, so in most Museum collections it will be found under the former specific name. Forel has made a new variety, which he calls _Var sanguineus_, of the coastal form found in North Queensland, with the head and thorax light reddish brown.

Most of the other species are small black ants: _Iridomyrmex rufoniger_ is very common in the bush and in the gardens; a variety which Forel has called _domesticus_ is the common black ant that comes into the house in Sydney, and is a regular pest in the summer in many districts. _Tapinoma minutum_ is about as large as the “Mound Ant”; black; the head and thorax deeply pitted and corrugated; the abdomen slightly constricted in the centre, smooth and shining. It comes from Townsville, N.Q.: a second species, _T. melanocephalum_, taken in Cairns, is also found in Samoa and the Tonga Islands.

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The last sub-family, CAMPONOTINAE, is a large division well represented in Australia; they live in more or less large communities, and with a few exceptions have the pupae enclosed in cocoons. The base of the abdomen forms a single node, and there is no constriction between the second and third abdominal segments; the sting is wanting, and the anal orifice is fringed with hairs. In the works of early entomologists a number of our ants were described under the Genus _Formica_, but they have been gradually identified and placed in their proper genera, until we only have about half a dozen still remaining in this genus, probably more on account of the difficulty of identifying them than because they really belong here.

The Genus _Acantholepis_ is represented by four species all described by Forel from specimens I have collected and sent him from N.S. Wales, so that their range seems to be restricted. They are all small, reddish brown, smooth, shining ants; _A. bosii_ was found under stones at Cooma, N.S.W.

The Green Tree-ant, _Oecophylla smaragdina_, found in tropical Africa, India, and New Guinea, is common in the tropical scrubs on the coast of North Queensland. They live in large communities among the foliage of the trees, in nests formed by webbing the leaves together into an irregular mass varying in size from a cricket ball to a man’s head. The material with which they make these nests is obtained by the workers, by squeezing the pupae and using the secretion they discharge. The winged female measures nearly ¾ of an inch in length, has a broad thorax and large oval body; the worker is only about ¼ of an inch, and slender in proportion, but for his size is the most pugnacious creature in the insect world; if one damages a nest pushing through the scrub, down tumble a swarm of green tree ants on one’s head and neck, and wherever they drop they stick their jaws in and hang on, and each one has to be picked off in detail. In these forests they destroy an immense number of insects, catching the little bees as they come out of their nests in the tree trunks, and dragging the small beetles off the twigs by main force. I have often seen half a dozen hanging on to the legs of a stout weevil, apparently trying to wear him out, for they would remain for hours in the same position, and probably succeeded in the end.

The great Genus _Camponotus_ contains about 400 described species from all parts of the world, of which about 60 are recorded from Australia. Most of them are found in open forest country, forming their nests in the ground, under logs or stones, or near the butts of trees. Several of our common species are known as “sugar ants,” as they come about at night and invade the pantry and store room in search of sweets; but they are omnivorous in their tastes, and will often come round the camp fire at night, prowling about for the small moths that flutter round, often rushing right into the edge of the ashes to capture a moth when it falls with singed wings. _Camponotus intrepidus_ is one of our largest species, varying from black to reddish brown in tint, and is thickly clothed with short hair. They form nests in the open sandstone country about Sydney, sometimes raising a little mound or producing a fragile funnel-shaped structure above the opening leading into the nest. The Sugar Ant, _Camponotus nigriceps_, is the commonest house species; it forms large chambers under stones or logs in which they all cluster together. The general colour is black, with all the abdomen except the base dull yellow, but the variations of the yellow and black are common; it measures to ¾ of an inch in length.

_Camponotus inflatus_ is the curious “honey ant” of Central Australia figured and described by Lubbock in his “Bees, Ants, and Wasps.” The naturalists on the Horn Exploring Expedition obtained a number of this and other species, described by me in the Zoology of this Expedition. The ordinary members of the “honey pot ants” are of the usual normal form, but certain individuals of each nest of these species are crammed with a honey secretion (probably obtained by the workers from aphids or psyllids), until the abdomen swells out of all proportion to the rest of the ant; the honey pot ants remain hanging about in the bottom of the nests like a number of bottles of honey, incapable of leaving the nest; the supply is probably used as food for the larvae. Spencer says that the blacks dig up these nests and look upon the “honey pots” as great luxuries. The honey is sweet with an acrid taste like the honey of our native bees. They are apparently common in Central Australia; Miss Ormerod sent me some from England which she had received from a correspondent at Kalgoorlie; and recently Mr. Field of Tennant’s Creek sent me a fine red species from the far north.

_Camponotus claripes_, a smaller pale coloured species, generally makes its galleries at the base of a tree trunk, and has a very wide range from Victoria to North Queensland. I found the cocoons of this species in a nest at Howlong infested with full grown red velvet mites (_Trombidiidae_), which occupied the whole space.

The Genus _Polyrhachis_ contains a number of black ants of fair size, most of which build their nests in dead logs, and live in rather large communities, but others form small nests by matting the foliage of trees together; the latter are confined to Queensland, and are generally smaller shining black forms. The true “wood ants” are more or less covered with bright metallic pubescence and fine hairs, and with the hind portion of the thorax and the node of the abdomen ornamented with a pair of slender spines.

_Polyrhachis ornata_ is black, with the thorax and base of the spines richly tinted with gold; it comes from Queensland. _P. ammon_, ranging from Victoria to Queensland, is clothed with pale golden pubescence lightest on the head and thickest on the abdomen. _P. semi-aurata_ has both the head and thorax golden, with the abdomen smooth, black and shining. _P. laevior_ is one of the smaller tree nesting forms, and is smooth and shining without any metallic tints, and the thoracic and abdominal spines are very small. _P. turneri_, also a northern form, has the head golden, and large well developed spines.

Family 14. Solitary Ants.

MUTILLIDAE.

Though these interesting little creatures were once placed in the Formicidae, and are still popularly known as “Solitary Ants” in Europe and “Cow Ants” in America, they are now classified as the first family of the fossorial wasps. Unlike the true ants, they are solitary in their habits and probably all parasitic in other insects’ nests. Until quite recently they were all placed in the Genus _Mutilla_, in which about 1,000 species have been described from all parts of the world, and about 130 from Australia; the earlier ones by Messrs. Westwood and Smith, the later ones by Andre, who has had the great advantage of obtaining a great many specimens from Mr. Gilbert Turner, who was able to sex the species, add valuable notes about their habits, and give the exact locality of the specimens collected. Turner, who was a most careful observer, after some years of collecting was not positive where they passed the earlier stages of their existence, but told me that he believed that some of them were parasitic in the nests of ants. Several of the European _Mutillidae_ are known to be parasitic in the nests of bees: I have on several occasions dug the females of the smaller species out of moss at the foot of tree trunks, and our two largest species are generally found under stones in open chambers, while on hot summer days both sexes of _Mutilla cordata_ and several other species are found running up and down the tree trunks.

The males are furnished with two pairs of dark or semiopaque wings. The head is rounded; the antennae curving round; with large eyes and ocelli; the thorax broad, but showing the segmental divisions, and the abdomen rather short and rounded, without any pedicle; the legs stout, and spined on the middle pair. The whole insect is rugose and deeply punctured or roughened, and more or less clothed with pubescence and longer hairs. The females are wingless, with shorter curled antennae, very different in size, sculpture, and even colouration to the males of the same species; with the body more elongated and terminating in a long powerful sting. Andre remarks upon the brilliant metallic colouration of many of the Australian species, which is much more pronounced than in those from other parts of the world. He also says that they resemble the American species in the fact that they can be divided into two groups by the configuration of the eyes.

Within the last few years specialists have subdivided the Genus _Mutilla_ into a number of new genera; and Andre places nearly all the Australian species in the Genus _Ephutermorpha_, but for simplicity I retain the old name.

_Mutilla rugicollis_, described by Westwood many years ago, is our largest species, measuring in the larger female over ¾ of an inch in length. She is black, very deeply punctured, thickly clothed with black and silvery white hairs, the latter forming white patches on the hind portion of the head, sides and under-surface of the abdomen, and has a dorsal row of five distinct spots down the back. The male is much smaller, with somewhat similar but not so distinct white markings, and is furnished with dark brown wings, which are hyaline, close to the sides of the thorax.

_Mutilla quadrisignata_ has about the same measurements as the female of the last species; with blackish hairy covering, except on the under surface of the abdomen, and four dark, reddish brown, oval spots forming a square on the dorsal surface. Both these species have a wide range over Australia. _Mutilla ferruginata_ is a smaller species with a similar deeply punctured surface; is of a uniform dull rusty red colour, thickly clothed with darker brown hairs; the legs and antennae deeper coloured than the body. _Mutilla cordata_ is typical of the smaller active forms that frequent tree trunks; the male is black with dark wings and slender abdomen, and measures about ⅓ of an inch in length; in this case much larger than the female, which has a rounded body with the centre of the dorsal surface occupied with a large rounded golden blotch. I have found the best time to collect these insects is in the hottest part of the day, when they are running up and down the larger tree trunks; but they are very active, and drop at the least alarm, so that it takes some practice to capture them.

Family 15. Flower Wasps.

THYNNIDAE.

These handsome flower wasps are closely allied to the members of the previous family, as they have similar wingless females of such peculiar shapes that, if examined alone, they would never be taken for the consorts of the large wasp-like _Thynnus_, with its long stout antennae, well developed legs, and large powerful wings. The males fly about the flowers of leptospermum and eucalypts, and when captured bite and pretend to sting by turning up the tip of the abdomen, which ends in a horny, harmless process. Fortunately, when hunted for in the summer, most of our commoner species can be taken _in copula_ with the smaller female, with which he flies about quite easily; when caught the female immediately detaches herself and falls to the ground, where she crawls out of sight, so that care must be taken by the collector to keep each pair captured in a box by themselves, or else when once mixed up it is impossible to determine unknown species. Australia is the headquarters of this group, for of about 400 described species, 300 are peculiar to this country; the others are chiefly confined to Brazil and Chili in South America, with a few from Asia and the Islands. Smith has described a great number in the British Museum Catalogues; Westwood others; and Guerin those collected during the Voyage de Coquille in 1830; but as many of these were determined from single specimens of one sex, it is certain that when a collection of sexed specimens can be compared with the types, the number of species will suffer considerable reduction.

Nothing definite is known about the earlier stages of their development; I have however obtained cocoons composed of a stout silken case enveloped in a thin outer second papery covering, oval in form, with a nipple-like projection at the extremity, from which I have bred one of our large species. These cocoons are buried several inches in the ground like those of the _Scolias_, so that the females, which are furnished with short, stout, spiny legs well adapted for digging, probably lay their eggs in lamellicorn larvae living in the loose soil.

A number of our common species are plentiful on the flowering Leptospermum and Melaleuca bushes, and many of the smaller ones may be found feeding upon the honey dew covering the foliage of small eucalypts that are infested with scale insects. _Thynnus variabilis_, our commonest species, is a very handsome wasp measuring over ¾ of an inch in length, and nearly 1¾ across the outspread wings; the general colour is brown; the front of the head, hind margin of thorax, and broad bands or double dots across the abdominal segments bright yellow; the semiopaque wings reddish brown. The female, very broad in proportion, is shorter than the male; she is reddish brown; the abdominal segments are rugose and blotched with yellow, forming transverse bars of rounded dots on the hind portion. The antennae are short and curled; the head broad, with a stout thorax; and she has short hairy legs. _Thynnus leachellus_, slightly smaller, is found in the vicinity of Sydney. The abdomen is broader and shorter in proportion; the general tint is black, richly marked on the head and thorax with bright yellow, and each of the abdominal segments carries a narrow transverse band of the same colour, broken by a dorsal stripe of black. The female is much smaller, short and thickset; is of a general reddish brown colour; the abdomen is marked with yellow blotches and bands, only the last one divided as in the male. _Thynnus flavilabris_, somewhat larger, is quite black, with only the face marked with deep yellow; the wings are dark, smoke-coloured; and the hind margin of the thorax is thickly covered with white hairs.

_Thynnus brenchleyi_ is a type of the North Australian forms; it is nearly as large as _T. variabilis_, but has the whole upper surface smooth and shining, the hind margin of the thorax and the base of the abdomen truncate and fitting close against each other. The head and prothorax are bright yellow, the rest black. This handsome insect was described by Smith in the Zoology of the Voyage of the Curaçoa, and it was said to come from the northern coast of Western Australia; my specimens were taken near Charters Towers, North Queensland. A female, sent with this species as its mate, is black, marked on the head, sides of thorax, and abdomen with yellow, and is furnished with a curious fringe of pale buff hairs on the hind margin of the thorax, and along the front of the first abdominal segment.

In the Genus _Rhagigaster_ the males are more slender in form; the abdomen, elongated and deeply constricted or corrugated at the junction of the segments, is usually black, with more or less dark coloured wings: the females are very small in proportion.

Among the most remarkable is the “Blue Ant,” _Diamma bicolor_. In this case the female is most common; about Sydney I have caught scores of females, but so far have never taken a male. She measures 1 inch in length, and is of a rich metallic blue to purple colour, smooth and shining, the antennae and legs reddish brown. She is furnished with a fine pair of jaws and a powerful sting, more formidable than that of any ant, and when disturbed turns over on her back and shows fight with both jaws and sting. The male, much smaller in size, is black, with red legs and black tarsi; the wings are semitransparent with black nervures. The whole upper surface of head and thorax is rugose, and the insect very ant-like in general appearance.

Mr. Roland Turner is at present engaged in working up the Australian Thynnidae at the British Museum, having his own and my collection of specimens to identify; probably this combined collection is the largest in existence, and contains an immense number of sexed specimens collected in the field, as we have both spent a great deal of time over these typical Australian insects.

Family 16. Hairy Flower Wasps.

SCOLIIDAE

These insects are easily distinguished from the Thynnidae in being thickset hairy wasps; both sexes are furnished with wings in which the neuration is distinct at the base, but the nervures fade out before they reach the tips; the thorax is broad, rounded in front, with a very short pedicle attaching it to the stout abdomen. The legs are stout, compressed, very hairy, and spiny, with one stout spur on the tibiae of the middle pair of legs well adapted for burrowing. The males are easily distinguished from the females in being more slender in form, with longer straight antennae (in the latter sex short, thickened, and curling round the sides of the head); and the legs are slender, with fewer spines. Several species are plentiful about the Sydney gardens and bush, where they can be easily captured on the flowers. In observations made by earlier entomologists, their life history seems to have been confused with those of the long legged sand wasps, which burrow in the ground and form regular nests provisioned with other insects and spiders; but the SCOLIIDAE form no true nest; the female burrows into the ground or under logs, where she finds the larvae or white grubs of the larger lamellicorn beetles, on which she deposits a single egg, first carefully stinging the beetle grub (according to Fabre, the French naturalist, who studied the habits of several European species). The young wasp hatching out attaches itself to the helpless grub in such a manner that it does not injure the vital organs, and by the time it has devoured its host it is ready to pupate, spinning a brown silken cocoon which fits into the cavity first occupied by the unfortunate beetle grub; when fully developed it digs its way up to the surface.

About 50 species have been described from Australia; Smith listed and described a number of new species (British Museum Catalogue Hymenoptera 1855): Saussure described several in the same year (Memoires de la Societe de Physique, &c., Geneve), and later on others in the Annals of the Entomological Society of France 1858. In 1864 he and Sichel monographed the family: Smith described 8 more four years after: and Kirby going through the British Museum Collections in 1889 revised the Genera and added another to our list.

_Discolia soror_ is our commonest shining black species; the female measures over 1 inch in length, and is easily identified by its beautiful, iridescent, opaque, dark blue wings. It may be often seen in our gardens on the flowers or hovering in numbers over a dead stump, looking for beetle larvae in which to deposit its eggs. _Scolia fulva_ is our largest species; the female measures up to 1½ inches in length, and is broad in proportion; it is black and reddish yellow, but so thickly clothed with coarse reddish hairs that it is more the latter tint; and the semiopaque wings are reddish brown. This species is figured and described by Gray in Griffith’s Animal Kingdom 1832.

_Scolia radula_ is a smaller black species, under 1 inch in length; the head, apex of thorax, base of abdomen and most of the under-surface are clothed with grey hairs, but the hind margin of the head and dorsal surface of abdomen are clothed with reddish brown; the latter is orange yellow above, but marked with black at the base and tip.

1. _Dielis formosa_ (Guérin). ♀. (1a.--Life size.)
2. „ „ Larva.
3. Pupal Cocoon, showing opening whence the wasp has emerged.

(“Agricultural Gazette,” N.S.W.)]