Australian insects

This division contains an immense number of very interesting insects which, though generally known as bees, ants, and wasps, comprise many other just as important families; some are unfortunately popularly called flies, such as saw-flies, gall-flies, and ichneumon-flies, but all true flies have only one pair of wings. Hymenoptera are, with a few exceptions, furnished with two pairs of semitransparent membranous wings, sometimes shaded with black or yellow tints, devoid of hairs or scales, but traversed by stout nervures forming irregular cells; the hind pair are the smaller, and are furnished with a row of spines along the front margin capable of hooking into the hind edge of the fore pair, thus adding to their powers of flight.

In a few anomalous groups we find the females wingless, such as Thynnidae, Mutillidae and others; in some like the fig insects Blastophaginae, the males are wingless and blind; in the ants, while the males and females are winged, the bulk of the community consists of wingless workers forming a third sex or caste.

These insects are furnished with well developed antennae; large compound eyes, in some groups composed of an immense number of facets; usually 3 simple eyes or ocelli, but these are sometimes wanting; a more or less tubular mouth adapted for sucking up food (commonly called the proboscis), though mandibles are always present. The thorax is stout and broad; the three primary portions, prothorax, mesothorax and metathorax, are distinct on the upper surface with well defined lateral or ventral plates. The legs are generally large, with spined tibiae, and slender tarsi terminating in a double claw or hook, but varying much in size and shape in the different families. The abdomen takes all kinds of remarkable forms, from the thickened sessile body of the sawfly to the slender stalked abdomen of the sand-wasp, and the female is furnished with an ovipositor, sting, or saw at the extremity.

The Hymenoptera are considered by naturalists to be one of the most highly developed or specialised orders of insects, on account of the social habits of some of the chief families, and the care they display in providing for the safety and food supplies of their larvae.

They undergo a complete metamorphosis: from the egg is hatched out a soft, generally legless larva which when full grown, if in a protected cell, is simply enveloped in a thin skin, but otherwise forms a stout silken or parchment-like cocoon; the larva usually takes a considerable time to change into the pupa; the change is not rapid as that of a butterfly.

Australia is very rich in hymenoptera; most of the typical families are well represented, and we also have a few very distinct groups peculiar to this country.

There have been many schemes of classification and sub-divisions of these insects proposed by various authors, and the present idea among specialists seems to tend to a still closer definition of the families, as exemplified in Ashmead’s recent Classification running through the pages of the Canadian Entomologist; but in a book of this kind, I can only deal with the most important divisions and refer my readers to the work of such specialists.

Westwood divided the first section, Terebranti, in which the females are provided with a more or less projecting instrument for depositing their eggs, into two sub-sections, Phytiphaga, in which the abdomen is sessile, and Entomophaga, in which the body is stalked. Some of the French entomologists had previously suggested dividing them up into five large families defined by the peculiarities of the ovipositor or borer. Kirby used the same terms as Westwood, but I have followed Sharp, who uses the names Sessiliventres instead of the first, and Petioliventres for the second, for they certainly express more clearly the form of the body of the groups under observation. The first group contains four families.

Family 1. Stem-Sawflies.
CEPHIDAE.

The first group comprises what Sharp terms “Stem-Sawflies,” which are not represented in Australia. They are slender little insects with long antennae; the larvae feed in the stems of plants; one damages wheat stems in Europe, another infests willows in America, a third is recorded from Japan; but they are unknown in Australia.

Plate X.—HYMENOPTERA.

Family Tenthredinidae.

Family 2.
ORYSSIDAE.

This family consists of the single Genus Oryssus, of which only 20 species are known. They are remarkable for the curious situation of the antennae on the under-surface of the head, the cylindrical rounded abdomen, and the exposed needle-like ovipositor. Turner has described one from Mackay, Queensland, in the Proceedings of the Linnean Society N.S.W. under the name of Oryssus queenslandicus. It is a small black insect measuring ½ an inch in length; with mottled brown wings, and typical shape of the genus.

Family 3.
SIRICIDAE.

These handsome Sawflies are common in Europe and America, the larvae living in timber; the members of the typical Genus Sirex have long cylindrical bodies rounded to the apex; the borer of the female extends beyond the tip of the abdomen. One species, Sirex australis, has been described from Australia by Kirby (List of Hymenoptera 1882). I have never heard of another specimen being found, and believe the type is unique.

Family 4. Sawflies.
TENTHREDINIDAE.

These are the typical stoutly built Sawflies, with the pronotum narrow, and the thorax generally broader than the head; the abdomen sessile, and provided in the female with a beautiful saw-like instrument on the under-surface of the tip of the abdomen, with which she slits the leaves to deposit her eggs in the tissue. The larvae are caterpillar-like creatures usually furnished with three pairs of legs; they feed upon the foliage of many plants.

Our species all belong to genera peculiar to Australia: Klug described several in the Berlin Magazin in 1814; Leach figured and described others in his “Zoological Miscellanies 1817”; Westwood described and figured a number in an important paper in the Proceedings of the Zoological Society 1880, others in his “Arcana Entomologica 1841”; and Kirby added to them in his List of Hymenoptera, B.M. Catalogue 1882.

The Genus Perga contains about 50 of our largest Sawflies, broad thickset insects, with reddish or light brown opaque wings, and short antennae forming an elongate club at the extremity. The larva is black or brown clothed with short scattered shining bristles, black head, three pairs of short stout legs, broad thorax, and abdomen tapering to a rounded tip. They feed gregariously upon the foliage of eucalypts, often stripping off all the leaves of the young bushes; they rest in the day time clustered together in a bunch of 50 or more round a branch, holding on with the legs; when disturbed they raise and rap the tip of the abdomen against the leaves, at the same time discharging a sticky yellow fluid from the mouth smelling strongly of eucalyptus extract. They are very subject to the attacks of dipterous and hymenopterous parasites, which these means of defence may keep away. When full grown they bury themselves in the soil, and form elongate, oval, parchment-like cocoons clustered together.

The Steel Blue Sawfly, Perga dorsalis, is slightly over 1 inch in length; is of a deep metallic blue, marked on face and thorax with bright yellow, and has stout reddish brown wings; the smaller male has the upper surface of the abdominal segments clothed with silvery pubescence. Perga kirbyi is dark reddish brown, similar in form and size to the last species; Perga lewisii, a much smaller yellowish brown insect, flattened on the dorsal surface, is common about Sydney upon the foliage of the “blood-wood” (Eucalyptus corymbosa), where she lays her eggs in the leaf in a double row, and stands over them until the tiny larvae hatch out and are able to move away; while thus occupied you can pick her up, but she will not move away, but raise her wings and fight like a hen over her chickens. Though this is our commonest species, and I have taken hundreds of females, I have never seen a male. Perga cameronii is like the last species, but larger, with more distinct markings on the back; it is found on the Blue Mountains.

In the Genus Pterygophorus about 10 species are described; they are much smaller insects, with bright metallic blue colours marked with reddish yellow; the male has the antennae produced into a comb or feathery structure, those of the female are formed of short rounded joints. The larva is a dull olive green creature covered with small warty tubercules; the head is broad, and the abdomen tapers off into a slender pointed tail; it has seven pairs of abdominal legs. It feeds upon the foliage of Leptospermum, wild dock and other plants, and when full grown bores into dead wood, pupating in a rounded oval cell.

The Ringed Sawfly, Pterygophorus cinctus, ½ an inch in length, is dark blue marked with deep reddish orange on the thorax, with a ring round the centre and tip of the abdomen of a similar colour; the wings are marked and clouded with black.

Plate XI.—HYMENOPTERA.

Family Tenthredinidae.

The Pale Coloured Sawfly, P. interruptus, slightly larger, has the thorax marked with orange yellow, and the abdomen deeply blotched with the same colour, forming interrupted bands on the sides; both these species are taken upon flowers in the summer months.

Philomastix glaber has very curious larvae that feed upon the wild bramble on the northern rivers of N.S. Wales; they have large heads, no abdominal legs, and two slender rat-like tails on the tip of the body. The sawfly measures 1 inch in length; the general colour is shining yellow, mottled with dull metallic blue on the thorax and abdomen; the semiopaque wings are barred with dark brown; the male has shorter antennae composed of short funnel shaped segments. There are a number of small species, belonging to the Genera Eurys, Euryopsis and Polyclonus, found chiefly upon flowers; Polyclonus atratus, sole representative of the Genus, has 18 jointed antennae, each joint furnished with a hairy finger turning inward at the tips. The Blister-leaf Sawfly, Phylacteophaga eucalypti, punctures the leaves of small gum trees; the larva feeds in the tissue, and when full grown pupates in a chamber in the centre, forming a distinct blister in the leaf: in the pupal state it has power to bend the body and rap against the side of the chamber. The sawfly measures ¼ of an inch in length; the male is black with a red head; the slightly larger female has the head and thorax reddish brown; the antennae have eight joints, long and slender. They have long stout legs, and are very active when they first emerge from the leaves, making a loud buzzing sound as they run about and try to escape.

Family 5. Gall-flies.
CYNIPIDAE.

This is the first group of the Petiolata, which are often known from their small size as Micro-hymenoptera. They are all small creatures, differing from the succeeding families in that they are broadly speaking plant eating, usually forming galls in which they live and pupate. However, there are some that live upon the gall-making forms; others live only upon the tissue of their cousins’ galls without disturbing their host; and again some that are known as inqualines (visitors that dwell in the cavity with the true gall-maker); so that their life histories are somewhat complicated.

The typical gall-fly deposits her eggs in the tissues of the selected plant by means of her ovipositor, which is beautifully adapted for the purpose; she injects in some cases a fluid that keeps the wound from closing up at once and so destroying the delicate egg. Most of the Cynips galls are rounded woody excrescences. The Gall Wasps have wings with few cells and no stigma; the front portion of the thorax is joined to the second; the ovipositor is concealed; the antennae straight, containing from 13 to 15 joints. I described three hymenopterons forming galls on wattles (Proc. Linn. Soc. N.S.W. 1892), but these insects submitted to Dr. Mayr some years afterwards proved to belong to another family. The only species described from Australia are 3 named by Ashmead (Pro. Linn. Soc. N.S.W. 1900), which were collected by Koebele without any exact locality being given; and Hypodiranchis aphidis described by me as a parasite of the common peach aphis in the Agricultural Gazette N.S.W. 1904.

Family 6. Parasitic Wasps.
CHALCIDIDAE.

This is a very extensive family, the members of which differ from the other small wasps in having the antennae elbowed, the first segment often as long as all the others combined; the antennae may be simple, but are often clubbed at the tips, and in the males of some groups with the segments or joints feathered or furnished with slender branching fingers. The delicate gauze-like wings are traversed by very few veins, and the abdomen is produced into all sorts of curious shapes, ornamented sometimes with remarkable anal appendages; and the ovipositor of the female, though often short, is sometimes much longer than the whole insect, and is usually prominent. These tiny little creatures deposit their eggs in the eggs, larvae, and pupae of other insects, wood galls, and excrescences produced by other insects, though a few groups are plant feeders and even produce galls.

Most of them are very minute, and can only be collected by keeping infested galls, leaves, eggs and cocoons in jars and breeding them out, so that the majority of them escape the eye of the ordinary collector, though among the most beautiful of all insects in rich colours and delicate structure.

Walker described a number of Australian species in the British Museum Catalogue, Hymenoptera 1846, others in his Monograph of the family 1839, and the Proceedings of other Journals (1863, &c.); but his usual locality is simply “New Holland,” and without access to the types one would have some difficulty in determining any species. Westwood obtained and figured some of our largest; and Haliday others in the “Entomologist” 1842; while the few others described are those obtained by the zoologists on the various scientific expeditions visiting this country. Ashmead has contributed the only modern paper (Pro. Linn. Society N.S.W. 1900) on these and other parasitic hymenoptera collected by Mr. Koebele and myself. The species in the Genus Leucaspis are large thickset chalcids, with the ovipositor curving round and fitting into grooves in the dorsal surface of the abdomen. Leucaspis darlingi was obtained by Westwood from the Darling Downs Queensland (I have specimens from Mackay Q.): it is black mottled with yellow, and has brownish wings; the hind legs are swollen: the antennae thickened; and it measures ½ an inch. L. australis was obtained by Walker from S. Australia. Nothing is known about their habits, but Leucaspis gigas in Europe lays its eggs in the nests of mud-dauber wasps, piercing the clay walls with its stout ovipositor. Trichoxenia cineraria, a slightly smaller black insect, is deeply punctured all over the dorsal surface of the head and thorax; the wings are clouded at the apex; and the upper surface of the body is thickly clothed with dense yellow down, thickest toward the apex. Specimens in my collection were taken about Sydney.

The typical Genus Chalcis contains a number of short stout insects, generally black, sometimes marked with yellow and brown; they are easily distinguished by the globular form of the thighs of the hind legs, which are sometimes nearly as large as the abdomen. These insects are chiefly parasitic upon the larvae of small leaf-rolling moths: Chalcis vicaria is black, with the base of the tibiae and tarsi yellow; it is common about Mackay Queensland. I have bred numbers of Chalcis phya, a small black species with white mottled hind legs, from the chrysalids of the lucerne moth (Tortrix glaphyriana). Another undetermined yellow legged species has been bred from the codlin moth pupa. Eurytoma binotata, a tiny black insect clothed with a white pubescence, has the pronotum spotted with yellow, and the antennae and legs marked with reddish brown; it can be bred from the galls on the twigs of the turpentine gum. E. eucalypti, a smaller black species, slightly over ⅛ of an inch, comes out of eucalyptus galls collected at Uralla N.S.W. The members of the extensive Genus Megastigmus are all obtained from galls; they are more elongate in form, with broad globular heads, the males with short cylindrical bodies, but the larger females furnished with bristle-like ovipositors turning upward often longer than the whole insect. Megastigmus brachyscelides measures ¹⁄₁₂ of an inch, and is black to dark brown marked with yellow; it is bred from the large galls of Brachyscelis crispa. M. iamenus, originally described from Tasmania, I have bred from another gall coccid (B. pileata); also a larger light yellow species bred from dipterous galls on the Snow-bush (Aster ramulosus) has been named by Ashmead M. asteri; M. brachychitoni, ⅙ of an inch, reddish brown and yellow, is common in the large fleshy galls on the Kurrajong tree.

Stilbula peduncularis is a remarkable looking insect, with broad, rich metallic coppery red head and thorax; the basal portion of the abdomen forms a slender stalk with the apical tip produced into a small oval club. I have had a closely allied form out of the pupal cocoon of the red bull-dog ant.

The Perilampinae comprise some of the largest and most remarkable chalcids: Thaumasura terebrator has been described and figured by Westwood; my specimens came from S. Australia, and were sent by Mr. Blackburn. It is a slender, rich metallic purple insect, about ¼ of an inch in length to the apex of the flask-shaped body, which is continued in a long jointed tail three times the length of the whole insect. T. femor-rubra is a smaller insect with a tail not so long as the body, and of a general black colour with transparent wings and reddish legs. Dinoura auriventris is a very curious, metallic tinted species ¼ of an inch in length, with the apical portion of the attenuated abdomen produced into four flanges. I have bred a number of these wasps out of the large wood galls of coccids (Brachyscelinae), chiefly B. pileata. Pteromalus puparum is an introduced parasite of butterfly pupae, and is common about Sydney, where it infests that of the orange feeding butterfly (Papilio erectheus). Another tiny little metallic tinted chalcid, Eupelmus antipoda, infests the eggs of our common mantis.

About twenty species of the cosmopolitan Genus Tetrasticus are described by Walker, chiefly from Tasmania. The allied Tetrastichodes froggatti is a very tiny creature, described by Ashmead from shot-like galls on the leaves of eucalypts. Euryischia lestophoni, a larger black insect with mottled wings, is interesting to economic entomologists, as it is a secondary parasite of the Cottony Cushion Scale (Icerya purchasi), feeding on the fly parasite.

The Blastophaginae are remarkable little creatures, for there is a very great difference in the sexes of the same species; the males, yellow or brown, wingless, and blind, are more like white ants in general appearance than chalcids. They breed in the interior of figs, and are numerous in Australia. Saunders (Trans. Ent. Soc. 1883) described our common species (Pleistodontes imperialis), found in the fruit of the Moreton Bay fig about March. The tiny male, ¹⁄₁₂ of an inch in length, is of the typical form and colour; the elongate, shining black female (which is figured) is so different a looking creature that it would never be taken for the opposite sex of the insect. Their life history and remarkable habits have been described in the Agricultural Gazette (June 1900). Idarnis australis, described in the same paper, is a slender, bright, metallic green wasp, with a long tubular ovipositor nearly twice the length of the whole insect, which she also uses by pressing it down against the fig to jump like an acrobat, as well as for puncturing the skin of the fruit. The insect I described as the supplementary male of P. imperialis, is, Dr. Mayr tells me, the wingless male of this species. Mayr in “Neue Feigen-Insekten 1906” states that he finds that my identification is wrong and this is not the one named by Saunders but a new species which he calls Pleistodontes froggatti, and places my Idarnis in his Genus Sycoryctes.

Plate XII.—HYMENOPTERA.

Family Chalcididae.

Additional species of Chalcididae have been added to our fauna by the researches of Messrs. Perkins and Koebele (Bulletins 1, pts. 6 & 8 Hawaii 1905). In the Encryritinae he describes 12 new species, most of them bred from the pupae of the Dryinids collected in Queensland, but a few from more southern regions. Chalcerinys eximia is only ¹⁄₂₅ of an inch in length; is of a rich metallic green tint marked with black and brassy-yellowish tints, and is furnished with long antennae. It ranges from Bundaberg to Sydney. In the Eupelminae he describes one new species parasitic upon the parasite fly, Pipunculus cinerascens, under the name of Anastatus pipunculi. It is a bright metallic green and purple little creature about ¹⁄₁₂ of an inch in length. One species of the Tetrastichinae, which he calls Ootetrastichus beatus, has been bred from the eggs of leaf-hoppers from both Queensland and Fiji, while another parasite on the eggs of a Jassid embedded in the branchlets of a Eucalyptus was bred in Southern Queensland. Perkins describes it under the name of Pterygogramma acuminata, a tiny creature not ¹⁄₂₅ of an inch in length, of general brown and yellowish tints.

Five species of the parasitic wasps belonging to the Mymaridae are described from Queensland. They are all tiny little creatures with slender feathered wings and long legs. They deposit their eggs in the eggs of different species of leaf-hoppers, and some species are very abundant. Four species of the more robust parasites belonging to the Genus Aphanomerus are also described as egg parasites from Queensland. After studying the galls and insects from the wattles which I described in the Proceedings of the Linnean Society 1892, as belonging to the Cynipidae, Dr. Mayr finds that the insects will not fit into any known genera, so he has formed the Genus Trichilogaster to contain T. maideni, which forms galls on the branchlets of Acacia longifolia, and T. a-longifoliae, which aborts the flower buds of the same wattle into oval or rounded red and yellow galls as big as marbles. He describes a third species I sent him, T. pendulae, forming rounded galls on Acacia pendula, and has made the remarkable discovery that the tiny wasp deposits a female egg, which forms the central cavity on the gall with a second male egg in a small cavity on the side of the same gall, so that a male and female wasp is always produced from each gall, and he thinks this will be the case with our two common species when they are examined.

Family 7. Micro-hymenoptera.
PROCTOTRYPIDAE.

In general appearance these tiny creatures, some of the smallest in the insect world, would seem to be almost identical with those of the previous family; but Ashmead says: “If the anomalous group Mymarinae are removed there will be no difficulty in distinguishing at a glance a Proctotrypid from a Chalcid,” and defines them thus: “In all true Proctotrypidae the pronotum extends back to the tegulae, and the ovipositor issues from the tip of the abdomen, the sheaths in a few abnormal cases being conjoined and forming a more or less cylindrical tube or scabbard for the reception of the two spiculae and the ovipositor proper.”

Sharp on the other hand considers that this is one of the most difficult groups of the Hymenoptera to define; to a specialist of course they can be easily separated, but anyone who first takes up the study of these Micro-hymenoptera (and bear in mind that we are talking about insects, so small that when a collector breeds them out in jars he has to liberate them upon a window pane that he may see them against the light), he will I think endorse Dr. Sharp’s decision. Besides the peculiarities of the abdomen previously noted, the antennae, sometimes twice the length of the whole insect, are composed of from 7 to 15 joints, and in the typical groups, though the first joint may be long, it is not elbowed as in the Chalcids, and is seldom branched. The wings are delicate, without any nervures, except in a few small groups where the veins are somewhat like those of small ichneumon wasps. The hind legs are generally longer than the others, and though some have the thighs swollen as in the Chalcids, they are as a rule much more slender, and the abdomen is usually pointed.

They can be bred from galls, particularly those of small Gall-flies (Cecidomyia), the eggs of all kinds of insects, and the larvae of small beetles, moths, and other wasps.

In Ashmead’s “Monograph of the Proctotrypidae of North America” nearly 600 species are described, and a number have been added since these were recorded in 1893. The Australian species are probably numerous, judging from my own observations when studying gall-making insects; but very few have been described. Westwood described four in his “Thesaurus Entomologicus, Oxford 1874,” belonging to the Bethyllides, the peculiarities of which he defines, and figures with coloured plates. Ashmead describes another (Pro. Linn. Soc. N.S.W. 1900) under the name of Ateleopterus longiceps, obtained by me in a hollow twig of a wattle tree; a shining black ant-like creature about ⅙ of an inch in length, rusty red legs, and transparent wings clouded at the base, probably parasitic on the larva of some wood boring beetle. Sierola antipoda was bred from the curious bract-like gall of Cecidomyia frauenfeldi on the twigs of Melaleuca bushes. A second species of this genus was collected by Webster, and forwarded to Ashmead, who named it after the sender.

In 1890 Riley described “An Australian Hymenopterous parasite of the fluted scale” in “Insect Life” which he named Ophelosia crawfordi; it is a tiny reddish brown wasp with a shining black body, and the wings obscurely barred with smoky brown; it is easily bred from this mealy bug, which it greatly keeps in check. Goniozus antipodum, described by Westwood from S. Australia, is a little shining black ant-like wasp which has been lately discovered destroying the grubs of codlin moth both in S. Australia and N.S. Wales. The larvae feed upon the outside of the grub, burying their heads in the tissue, and when full grown spin a loose silken cocoon.

Perkins has recently added a number of new species to this family belonging to the Dryinidae. In his Bulletins Hawaii 1905, Nos. 1 & 10, “Leaf Hoppers and their Natural Enemies,” he describes 45 new species, chiefly collected by Koebele in Queensland, but some from the neighbourhood of Sydney. These curious little proctotrypids are parasitic upon the larvae and pupae of the small homopterous insects commonly known as Leaf or Frog-hoppers (Families Jassidae and Fulgoridae). The adult wasp captures the insect, holding it with its curious clawed feet while it deposits its egg in its body; when full grown the larva spins a white silken cocoon, from which the active winged insect emerges in about 18 days.

Gonotopus australis is a tiny wingless ant-like creature about ¹⁄₁₂ of an inch in length, which attacks jassids and fulgorids feeding upon grass and low herbage. This species comes from Bundaberg Queensland; but Koebele has bred a second species about ⅛ of an inch in length, of a general brownish colour, from a Jassid collected near Parramatta. The curious little sacs or larval bags of these parasites can be readily noticed projecting from the sides of the thoracic segments. Most of these insects have well developed wings, but, according to Koebele’s observations, they stalk their prey when looking for the host for their egg.

Family 8. Larger Parasitic Wasps.
ICHNEUMONIDAE.

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.

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.

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.

Plate XIII.—HYMENOPTERA.

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.