An elementary manual of New Zealand entomology

Frontispiece.

Fig. 1. Bolitophila luminosa. 1a. Larva, 1b. Pupa.

AN ELEMENTARY

MANUAL

OF

NEW ZEALAND ENTOMOLOGY.

BEING

OF

OUR NATIVE INSECTS.

WITH 21 COLOURED PLATES.

BY

G. V. HUDSON, F.E.S.,

WELLINGTON, NEW ZEALAND.

West, Newman, & Co., 54, Hatton Garden.

1892.

To

The Right Hon. LORD WALSINGHAM,

M.A., F.R.S., F.L.S., F.Z.S.,

LATE PRESIDENT OF THE ENTOMOLOGICAL SOCIETY OF LONDON,

THIS LITTLE BOOK IS RESPECTFULLY DEDICATED

BY THE AUTHOR.

PREFACE.

The object of the present volume is to give a brief account of the Natural History of the insects inhabiting New Zealand in a form intelligible to the ordinary reader. For this reason every effort has been made to avoid all unnecessary technicalities, and to adapt the book as far as possible to the requirements of youthful entomologists and collectors.

Several very elaborate systematic lists and descriptions have been published from time to time of the insects of New Zealand, amongst which may be specially mentioned—Captain Broun's "Manual of New Zealand Coleoptera," the illustrated "Catalogue of New Zealand Butterflies," edited by Mr. Enys, and Mr. Meyrick's "Monographs" of various groups of the Lepidoptera; but as yet no attempt has been made to present the subject in a suitable form for beginners.

It is hoped that this book will, to some extent, fill up the blank, and help to render what is now one of the most popular natural sciences in Europe, equally appreciated in New Zealand.

The author is much indebted to Captain Broun, Mr. R. W. Fereday, Mr. E. Meyrick, and others, for assistance in identifying the various species mentioned in this work.

Wellington, New Zealand, 1891.

CONTENTS.

AN

ELEMENTARY MANUAL

OF

NEW ZEALAND ENTOMOLOGY.

———

CHAPTER I

In the present chapter I propose to give a brief sketch of the general principles of Entomology, including a rudimentary glance at the anatomy and classification of insects; after which I think the reader will be in a better position to study the habits and life-histories of the individual species which follow.

The first requisite is a definition of what constitutes an INSECT.

An Insect is an articulate animal having the body divided into three distinct divisions, viz., the HEAD (Fig. I. A), the THORAX (B), and the ABDOMEN (C). It is furnished with three pairs of legs, and generally has two pairs of wings, and to acquire this structure the creature passes through several changes, termed its metamorphoses. The head exhibits no distinct divisions, but bears the following appendages: the eyes, antennæ, and organs of the mouth, or trophi.

The eyes are of two kinds, compound and simple. The former (Fig. I. c c) are situated on the sides of the head above the mouth, and consist of two large hemispheres, composed of a great number of hexagonal divisions, each of which is a complete eye in itself. The latter (s s) are usually three in number, and are situated on the top of the head between the compound ones. They are, however, frequently wanting.

The antennæ (a) are two jointed organs, one of which is placed on each side of the head, between the eyes; their functions are at present extremely doubtful, but they are invariably found in all insects.

The organs of the mouth consist of the following: the labrum (Fig. II. 3), or upper lip, a horny plate, closing the mouth from above; the mandibles (1 1), or upper jaws, two strong bent hooks, articulated to the head on each side of the mouth, and opposed to one another like scissor blades; the maxillæ (2 2), or under jaws, resembling the mandibles, but more delicately constructed, and furnished with a pair of jointed appendages termed maxillary palpi (5 5); and the labium (4), or lower lip, consisting of a horny plate somewhat resembling the labrum, but provided with two jointed appendages termed the labial palpi (6 6). All these organs are subject to great modification in suctorial insects, which I shall notice further on, when dealing with the differences between the various orders.

The thorax consists of three primary divisions, viz., the prothorax (Fig. I. b), mesothorax (d), and metathorax (k). The upper surfaces of these are termed the pronotum, mesonotum, and metanotum respectively, and the under the prosternum, mesosternum, and metasternum; other divisions exist in some insects, but they are not of a sufficiently general character to be noticed here. The six legs are attached to the under surface of the thorax, a single pair to each division; they are composed of the following joints: coxa (Fig. I. n), trochanter (o), femur (p), tibia (r), and tarsus (s).

Fig. I.—Body of an insect (Hymenoptera), showing the principal divisions: A, head; B, thorax; C, abdomen; a, antenna; c, compound eyes; m, mandible; s, simple eyes; b, prothorax; d, mesothorax; k, metathorax; 1W, fore-wing; 2W, hind-wing; n, coxa; o, trochanter; p, femur; r, tibia; t, tarsus; 1 to 9 segments of the abdomen.

Fig. II.—Oral and digestive system of Deinacrida megacephala (this insect is drawn on Plate [XVIII]., fig. 2): 1, mandibles; 2, maxillæ; 3, labrum; 4, labium; 5, maxillary palpi; 6, labial palpi; 8, œsophagus; 9, crop; 10, gizzard; 11, pancreas; 12, stomach; 13, biliary vessels; 14, ilium; 15, colon; 16, anus.

The wings are attached to the meso- and metanotum; they consist of two membranes traversed by numerous horny ribs (Fig. I. 1W and 2W).

The abdomen is made up of nine segments (C 1 to 9), some of which are not infrequently wanting. It contains the organs of nutrition, circulation, and generation.

The digestive system, the structure of which is apparent from Fig. II., consists of the following divisions: the throat, or œsophagus (8); the crop (9); the gizzard, or proventriculus (10); the pancreas (11 11); the stomach, or ventriculus (12); the biliary vessels (13 13 13); the ilium, or little gut (14 14); and the colon (15); ending in the anus (16). In the suctorial tribes, the crop is modified into a very peculiar organ, termed the sucking stomach, which presents itself as a small bag, attached to the throat by a thin tube. This bag exhausts the air from the throat, when the insect is sucking, thus producing a vacuum therein, and causing a rapid ascent of fluid into the stomach.

The heart of insects consists of an elongated tube lying along the back, and termed the dorsal vessel. It is composed of a variable number of chambers, the blood being driven forward towards the head by its contractions. These motions may be easily seen in transparent species.

The breathing organs are distributed throughout the body in the form of numerous minute air-tubes, which are supplied with air from a variable number of apertures, situated on the sides of the insect, and termed spiracles.

The nervous system consists of a chain of ganglia, running down the ventral surface of the insect, and analogous to the spinal cord of higher animals. The number of ganglia varies greatly among the different tribes.

The metamorphosis of insects, which I have previously mentioned as one of their most essential attributes, consists of four distinct stages, viz., the Egg, Larva, Pupa, and Imago.

The eggs of these animals exhibit a great diversity in shape among the different species. They are deposited by the parent with unerring instinct on substances suitable for the food of the larvæ, which, in the majority of cases, is quite different from that on which she herself subsists.

The larva state immediately succeeds the egg, and is spent almost exclusively in feeding, the insect growing at a great rate, and being frequently compelled to change its skin.

The pupa is usually completely quiescent, the insect being at this time quite incapable of any motion, except, perhaps, a slight twirling of its abdomen. Exceptions to this rule occur, however, in two of the orders, in which the pupa state does not differ materially from that preceding it.

In the imago, or perfect state, the insect appears under its final form, with every organ completely developed.

We will now consider the seven great divisions, or Orders, into which insects are divided, the complete knowledge of which is one of the most important elements in the entomologist's preliminary education. I trust that by a careful perusal of the following definitions, aided by references to the Plates, which illustrate numerous members of each order in their several states, the reader will be enabled to master the subject without much difficulty.

Order I.—COLEOPTERA.

Wings four; the anterior pair (termed elytra) horny and opaque, the posterior membranous, and employed in flight; mouth masticatory. The larva a grub with or without legs, but a distinct head always present. The pupa inactive, taking no food, the limbs of the future insect enclosed in distinct cases, and applied closely to the body. This is the largest of the Orders, and consists of all those insects popularly known as Beetles. (Plates [I]. and [II].)

Order II.—HYMENOPTERA.

Wings four, membranous, the posterior pair being the smaller, and connected with the anterior during flight by a row of minute hooklets; mouth masticatory, the maxillæ and labium being elongated, in many of the families, into a long sucking instrument or "tongue." Metamorphosis as in the Coleoptera. A large Order, containing the numerous tribes of Sawflies, Bees, Wasps, Ants, and Ichneumon-flies. (Plate [III].)

Order III.—DIPTERA.

Wings two; the posterior pair represented by two minute clubbed appendages termed poisers; mouth a suctorial tube formed by an elongation of the labium, enclosing within it a variable number of setæ answering to the mandibles, &c., of biting insects. The larva without legs, a distinct head being often absent. The pupa inactive, the limbs of the imago firmly attached to the body, but plainly visible. Among the majority of species included in this Order the larval skin is not cast away, but envelopes the insect in a hard shell; the true pupa is consequently only visible on the removal of this covering, when it is found to closely resemble those in which no such arrangement occurs. The Order comprises the numerous Gnats and two-winged Flies. (Plates [IV]., [V]., [VI]., [VII].)

Order IV.—LEPIDOPTERA.

Wings four, generally covered with scales; the anterior pair slightly superior in size; mouth suctorial, the maxillæ forming a spiral tongue, which is coiled between the large labial palpi when not in use; other oral organs rudimentary. In many instances the whole mouth and alimentary canal are more or less obliterated, a considerable number of the species taking no food in their final state. The larvæ always possess a distinct head and six thoracic legs, and in addition a variable number of prolegs are often present on the abdominal segments. Pupa inactive, the limbs of the future insect being usually indicated by lines in the integment. This Order contains all the varied tribes of Butterflies and Moths. (Plates [VIII]., [IX]., [X]., [XI]., [XII]., [XIII].)

Order V.—NEUROPTERA.

Wings four, of equal size, membranous, and traversed with numerous branching ribs; the mouth masticatory, and in many instances but slightly developed. Larva with a distinct head and three strong thoracic legs; chiefly carnivorous. Pupa inactive; the limbs very perceptible and loosely applied to the body, but incapable of distinct motion. A small Order, comprising the Stoneflies, Lace-wings, Ant-lions, &c. (Plate [XIV].)

Order VI.—ORTHOPTERA.

Wings four, of nearly equal size; the anterior pair often more or less leathery, but with distinct veins. The larva and pupa closely resembling the imago; the latter with rudimentary wings. In the instances where these organs are wanting in the mature insect, the metamorphosis merely consists of a series of moultings, and it is consequently a matter of some difficulty to determine when the insect is full-grown. This Order is of small extent; it includes the Earwigs, Cockroaches, Grasshoppers, Crickets, Termites, Dragonflies, Mayflies and Perlidæ; the last four being transferred from the Neuroptera of most authors. The minute species of Mallophaga and Thysanura will also come under this heading. (Plates [XV]., [XVI]., [XVII]., [XVIII]., [XIX].)

Order VII.—HEMIPTERA.

Wings four, in some cases wholly membranous, but in a large proportion of the families the basal portions of the anterior pair are horny, and form protective cases for the other pair when not in use; mouth suctorial, consisting of an elongate rostrum, enclosing four fine setæ. The larva and pupa resemble the imago, the latter being active, with rudimentary wings. In a few instances, a slight divergence from the parent form is shown in the preparatory states (Cicadas, &c.). This is a small Order, containing the Cicadas or "Singers," Bugs, Plant Lice, and all the suctorial animal lice. (Plate [XX].)

After the Orders, the divisions to be considered are the Groups, Families, Genera and Species.

Groups are large divisions immediately subordinate to the orders, and consist of a number of kindred families. They are of great assistance to the student in dealing with the very large Orders, such, for instance, as the Coleoptera.

Families, again, consist of a number of allied genera, and Genera, in the same way, of allied species.

With regard to the Families, I have in the main followed those of Professor Westwood in his 'Modern Classification of Insects,' as most recent writers appear very much divided in opinion as to the correct limits of these divisions. Much diversity also prevails with respect to the proper definitions of Genera and even Species, but I have deemed it best to follow the authority of the latest catalogues in this matter, as any changes in nomenclature are always liable to produce confusion.

CHAPTER II

So many excellent essays have been written on collecting insects that it would probably be a most difficult task to supply much fresh information on the subject; but as many of my readers may be unable to consult works specially devoted thereto, the present chapter will, perhaps, be of some value in showing them a few of the most convenient methods of collecting insects in New Zealand.

Coleoptera, or Beetles, may be found almost everywhere. Overturning logs and stones, peeling off bark, and cutting into the solid wood of trees, all produce a great variety of species. A small axe and an iron wrench, shaped something like a chisel, but bent round at the upper end, are the best instruments for working old trees. The bark should be all stripped off and examined, as well as the surface of the log underneath. The same remarks apply to stones, which should be searched as well as the places from which they were removed. Sacks, if left about the fields for a few weeks, often harbour good beetles, and when found they should always be pulled up and examined.

An umbrella, held upside down under flowering shrubs in the forest, will often be found swarming with beetles after the plants have been sharply tapped with a stout walking-stick. The same object may be attained by spreading a newspaper, or sheet, under the trees and then shaking them; the beetles will fall on to the sheet, and may then be captured. The only advantage of the umbrella is that it can be more readily used in awkward places, such as on steep hill sides.

The dead bodies of birds and animals also contain peculiar species; they may be held over the umbrella and shaken into it, when the inhabitants will fall out, and can easily be obtained. Dead fish on the sea beach are often very productive. Moss and fungi are unfailing resorts of many of the smaller species of Coleoptera, and can be examined in the winter when the entomologist is otherwise idle.

Beetles should always be brought home alive. The small round tin boxes sold with Bryant and May's wax matches will be found very serviceable for this purpose. These boxes are far better for all kinds of collecting than either pill- or chip-boxes, as they do not break when knocked about. A separate box should always be given to a large or rare species, but most of the smaller kinds will travel quite safely in company, especially if a wisp of grass or a leaf is put into the box to give them foothold.

Beetles must be killed with boiling water, and left immersed some hours before setting. They must be pinned through either the right or left elytron, and each collector must always keep to one side, as nothing looks worse than to see some of the specimens pinned on the right and others on the left side. When pinned the beetles are set on a corked board, the legs, &c., being placed in a natural position, and retained until dry by means of pins and pieces of paper and card. The smaller species should be mounted with transparent gum on a neat piece of card, which can be pinned in the store-box or cabinet with the others. The greatest care should be taken to set symmetrically, so that the limbs on the right-hand side of an insect are in the same position as those on the left.

Hymenoptera may be captured with the ordinary butterfly-net, and are found abundantly during the summer. The larger species are pinned through the centre of the thorax, and set in the same way as Coleoptera, the smaller ones on card with gum. These insects should, if possible, be made to fly into the vessel of boiling water, as by this means they generally die with their wings expanded, which is a great assistance when setting them. This can usually be managed by holding the box containing the specimen immediately over the water, and giving it a sharp tap with the finger of the other hand.

Diptera are also captured with the net, and pinned in the same way, but should be killed with the laurel bottle.

Lepidoptera are the most difficult of all to collect, and are at the same time the most attractive to beginners. They may be captured with a net made of fine gauze (mosquito net dyed green is the best material); the frame to support the net is constructed of a piece of cane bent into a hoop, each of the ends being supported in a forked tube shaped like a Y, and the long tube, forming the base of the Y, is firmly fitted on to the end of a walking-stick. This form of net is light, strong, and easily made; the only thing requiring special attention is the Y, but this can be readily made by any tinsmith out of two pieces of gas-pipe of different sizes, the larger one for the stick, and the smaller one for the ends of the cane to fit into. The collector should also be furnished with a number of small tin boxes.[^[1]] All this apparatus can easily be packed into an ordinary satchel.

When the entomologist reaches his hunting-ground, he will mount his net and place a number of the boxes in his left-hand coat pocket. The foliage of all trees and shrubs should be vigorously beaten and the insects captured as they fly out. When a moth is taken, the collector will first turn the net half way round so as to close the entrance, and then, directly the insect ceases fluttering, he should carefully place one of the little boxes over it and slip on the lid. The box is then transferred to the right-hand pocket. He will soon learn to do this without in any way damaging the insect. On arrival at home, the insects should be immediately killed in the laurel bottle. This is an ordinary wide-necked bottle with a small bag of well-bruised young laurel shoots at the bottom, covered with a circular piece of card fitting accurately to the sides of the bottle. Laurel shoots can always be obtained about the middle of October, when several killing bottles can be prepared. They must always be wiped out before using, and kept carefully corked. After a few hours the insects should be tilted out of the bottle on to a tablecloth, and pinned exactly through the centre of the thorax. The rough surface of the tablecloth prevents them from slipping during the operation. About one-third of an inch of pin should project below the body of the insect. If a moth or butterfly dies with its wings folded upwards over the back, it must be carefully picked up between the thumb and index finger of the left hand, and the pin inserted with the corresponding fingers of the right hand. When all are pinned they should be transferred to a tin box, lined with cork, which has been previously well damped with water. While pinning them into this box great care must be taken not to allow the wings to come in contact with the damp cork. In about twenty-four hours the specimens thus treated will be ready for setting. This process is performed by means of corked boards of various widths for different sized species. Each board has a groove down the centre for the bodies of the insects to rest in, while the wings are spread out on either side. They should be carefully moved forwards with a fine-pointed needle to the desired position, and retained by strips of tracing cloth pinned firmly down at the ends. These strips must not be removed until the insects are thoroughly dry and ready to place in the store-box or cabinet. In setting Lepidoptera, as with other insects, symmetry and a natural position are the main points to be aimed at, special care being taken that the antennæ, fore- and hind-legs, and wings, are shown in correct positions, the middle pair of legs being of course, in the majority of cases, hidden by the wings. It is almost needless to say that different sized pins should be used for various insects, but this point must be left to the discretion of the collector. Entomological pins of all sizes can be obtained from James Gardner, of 29 Oxford Street, London. Gilt pins are useful for many species which are liable to form verdigris on the pins, and are universally employed by many entomologists, but are probably not so strong as the silvered ones.

Many species of moths are only to be found at night. When working at this time the collector must suspend a bulls-eye lantern round his neck or waist, and can then have both arms free for capturing insects on the wing or at blossoms. Honey mixed with a little rum, and applied with a small brush to the trunks of trees a few minutes after sunset, will, on some evenings, attract large numbers of valuable species, but not infrequently it is quite unproductive. This mode of collecting has been termed "sugaring" by entomologists, and may be employed during the whole summer. The best blossoms for attracting insects in New Zealand are those of the white rata,[^[2]] which blooms in the forest from February till April, and from which the collector may generally rely on getting a rich harvest. The insects can usually be slipped directly from the flowers into the killing bottle.

This is much better than netting them, although occasionally one will escape during the process. When dead the specimens should be placed in a small tin box which has been filled with cotton-wool, packed very lightly. In this way a large number of moths may be carried a long distance with perfect safety, and the extremely inconvenient process of pinning them in the field obviated. If Jahncke's patent boxes are employed it is quite unnecessary to kill the moths in the field. They can be boxed directly from the blossoms and taken home alive without suffering any injury.

Lepidoptera, and in fact all insects, are attracted by light, and in some situations the collector will find that he may frequently obtain good species by merely opening his sitting-room window and waiting for the insects to arrive. Much of course depends on the situation of the collector's residence and the nature of the night, which should be dark and warm. I have occasionally tried taking a lamp into the forest to attract insects, but have not met with much success. In swampy and flat situations, no doubt, attracting by light would be very effective, especially if a powerful lamp was employed, in an exposed situation, with a sheet behind it, supported between two poles. This method has been followed with great success by many English entomologists in the fens, but has not yet been tried in the New Zealand swamps, where it would probably be the means of bringing many new and interesting species to "light."

With regard to collecting members of the three remaining Orders but little need be said. Neuroptera can be treated in the same way as Lepidoptera, but they should be set on flat boards. The treatment of the Orthoptera will resemble that of the Coleoptera, but the larger species will require to be stuffed with cotton-wool before setting. A few of the largest species of the Lepidoptera must also be stuffed. For this purpose the specimens should be placed on their backs on a piece of clean glass so that none of the scales may be rubbed off. After the contents have been removed, a little chalk should be introduced into the abdomen with the cotton-wool. Hemiptera can be collected and set like Coleoptera, but some of the more delicate species, such as the Cicadæ, should be killed in the laurel bottle instead of in boiling water.

Before concluding the present chapter I should like to say a few words on the subject of rearing insects, which the entomologist will soon learn to regard as by far the most interesting method of acquiring specimens for his collection.

Members of the Coleoptera are probably the most difficult insects to rear in captivity. Their larvæ may be kept in ordinary jam-pots covered with perforated zinc, and filled with earth or rotten wood. The carnivorous species must, of course, be supplied with the animals on which they feed. Beetle larvæ are often some years in attaining maturity. Many of the Hymenoptera and some of the Diptera are parasitic on the larvæ of the Lepidoptera; they are consequently found in rearing these insects, and their economy should always be carefully recorded.

Lepidoptera are, perhaps, the most satisfactory insects to rear. Most of the larvæ feed on the leaves of different plants, and all that is needed is to keep them well supplied with fresh food.

So great a variety of cages have been devised for the rearing of caterpillars that it would be quite impossible to describe them here. I will therefore only give a short account of those which I have used myself, and have found so convenient that I do not hesitate in recommending them to those entomologists who wish not only to rear insects but to study their habits.

The cages I have been in the habit of using are made of two or three thicknesses of cardboard bent round into a cylinder and strongly pasted together. They may be of various sizes, from three to four inches in diameter up to eight or ten, and constructed so that one will go inside the other. The height should exceed the diameter by about one and a half inches. The cylinders should be made so as to stand exactly level on a flat surface, and they should have two rows of small openings round the sides for the admission of air. It is a good plan to have four of these openings in each row and place them opposite one another. They should be covered on the inside with gauze, stiffened with green or brown paint, as the dark colour will enable the observer to see inside more readily. A circular piece of glass is fitted into the upper end of the cylinder, and fixed by means of paste and paper. The base of the cage consists of two round pieces of wood, one about half an inch smaller than the other, the smaller one nailed exactly in the centre of the larger piece. These are made so that the cardboard cylinder fits accurately on the outside of the smaller piece of wood. The whole cage is then neatly covered with white paper inside and brown outside. A complete view of the interior can of course be obtained by looking in at the top, while the cages can be stowed away one within the other when not in use. A stone ink-bottle should be put on the floor of each cage and filled with water, into which a sprig of the food-plant can be introduced. Care must be taken to plug up the mouth of the bottle, so that the larvae may not crawl down the stem of the plant into the water and thus meet with an untimely end. This may readily be done by means of a cork with a hole bored in it for the stem to pass through, or a plug of moss or blotting-paper. Members of almost all the orders can be reared in these cages, as jam-pots full of earth may easily be introduced, in the place of the stone bottle, when required for species which bury. A circular piece of blotting-paper should be placed over the bottom of each cage, while larvæ are feeding in them, and renewed when at all soiled. The excrement must also be removed when the larvæ are supplied with fresh food. As a rule, this is only necessary about twice a week, as the water will keep most plants fresh for quite a lengthened period. When it is necessary to remove a larva it should always be done with a fine camel-hair brush, never with the fingers. Generally, however, it is better to allow the larvæ themselves to crawl from the old sprig on to the new one, which they usually do in a few hours after the food is changed. The old plants should of course then be taken out so as to afford more room for fresh air.

Many female moths may be induced to lay their eggs in captivity, especially if put in a box with some of the food-plant of the larva. It is extremely instructive and interesting to rear an insect from the egg. When the young larvæ first emerge they must be kept in a tumbler with a piece of glass put over the top, as they might escape through the ventilators of the cages, but they ought to be transferred immediately they are large enough. When rearing a lot of caterpillars from a batch of eggs, care should be taken to avoid overcrowding.

A collection of insects should always eventually be placed in a neatly constructed cabinet. They should be arranged in rows, systematically, with the correct names under each species, and the name of the order or group at the commencement of each drawer. Numerous modifications in arrangement are often needed to meet the requirements of different sized insects, but an inspection of any good collection will at once explain the general principles. Camphor should be pinned in the corner of each drawer or store-box, and the whole collection fumigated with carbolic acid, or equal parts of oil of thyme, oil of anise, and spirits of wine, every six months. These can be introduced in a watch glass containing a small quantity of the chemicals on a pellet of cotton-wool, care being taken not to stain the paper at the bottom of the drawer. For the same reason, while using carbolic acid, the camphor should be taken out, as otherwise it will "sweat." All boxes for the reception of insects must of course be lined with cork and paper.

It is most important that an accurate record should be kept of every specimen that is placed in the collection. This may be done by attaching to the pin underneath each insect a small numbered label, which refers to a book containing locality, date of capture and other particulars.

I have found it a good plan to give every species a number, and every specimen a letter. Thus, supposing Vanessa gonerilla is numbered "6," the first specimen taken would be "6a," the second "6b," and so on, all the specimens, perhaps, having different dates and localities. This system is very convenient when specimens are sent away to be identified by another entomologist, as, provided the collector always retains a single specimen of the species which he desires named, it obviates the necessity of having his specimens returned, the number showing at once to what species the name refers. At least five lines should be allotted to each species in the collection journal, and the writing should be small but distinct.

A collection formed in this manner will not only be a constant source of pleasure to the collector and those who succeed him, but very probably of great value in deciding many important questions in entomological science.

CHAPTER III

The observations on the natural history of the New Zealand beetles, forming the subject of the present chapter, are much less numerous than might have been expected from the great number of species which have been described. The difficulties attendant on rearing these insects are, however, very great, and it thus happens that the life-histories here given bear a smaller proportion to the number of the Coleoptera than will be found to be the case with the majority of the other Orders. I hope, however, that the few details I have collected, referring to the following species, may induce some of my readers to investigate others for themselves.

Group Geodephaga.

Family Cicindelidæ.

Cicindela tuberculata (Plate [I]., fig. 1, 1a larva).

This is a very abundant insect found throughout the country in all dry situations. It delights in hot sunshine, and may be constantly observed flying from our footsteps with great rapidity as we walk along the roads on a hot summer's day.

Its larva (Fig. 1a) is an elongate fleshy grub, the head and first segment being horny and much flattened, and the body provided with two large dorsal humps, each bearing at its apex a slender curved hook.

The burrows of these insects are very conspicuous, and must have been noticed by every one, in garden paths, sandbanks, and other dry situations; they are sometimes very numerous, and may be best described as perfectly round shafts, about one line in diameter, and extending to the depth of three or four inches, generally slightly curved at the bottom. The sides are perfectly smooth, and the larva may be often discovered near the mouth of its burrow, using its dorsal hooks to support it, and thus having both legs and jaws free to dispose of the unfortunate insects that fall into its snare. These usually consist of flies and small beetles, which appear to be urged by curiosity to crawl down these pitfalls, and thus bring about their own destruction. By reference to the figure it will be seen how admirably the hollowed head and prothorax serve the purpose of a shovel to the larva, when forming its shaft. These burrows are first observed about the middle of November; the perfect insects coming abroad three weeks or a month later, when they may be often seen in the neighbourhood of their old domiciles. They are very voracious, devouring large quantities of flies, caterpillars, and other insects, some of which are much superior to themselves in size. On one occasion I saw a male specimen of Cicindela parryi (a species closely allied to but smaller than C. tuberculata) attack a large Tortrix caterpillar, an inch and a half in length. The beetle invariably sprang upon the back of the caterpillar and bit it in the neck, being meanwhile flung over and over by the larva's vigorous efforts to free itself from so unpleasant an assailant. During the fight, which lasted fully twenty minutes, the beetle was compelled to retire periodically to gain fresh strength to renew its attacks, which were eventually successful, the unfortunate tortrix becoming finally completely exhausted. The beetle devoured but a very small portion of the caterpillar, and abandoning the remainder went off in search of fresh prey. Eight other closely allied species of Cicindela are described by Captain Broun in the "Manual of the New Zealand Coleoptera," but they offer no especial peculiarities, and C. tuberculata may be taken as a type of the genus.

Family Carabidæ.

Pterostichus opulentus (Plate [I]., fig. 3, 3a larva).

This fine beetle is very common in most wooded situations in the Nelson district; it may be at once distinguished from the numerous other closely allied species by the beautiful metallic coppery tints that adorn its thorax and elytra.

During the day it is usually discovered concealed under logs and stones, and when disturbed, rushes into the first crevice to get out of the light. At night time, it comes abroad to feed, killing an immense number of flies, caterpillars, and other insects, to satisfy its voracious appetite. Although of a most ferocious disposition, it is not wanting in maternal affection. The female, when about to deposit her eggs, excavates a small cavity nearly three inches square, in which they are placed. These she broods over until hatched, and probably some little time afterwards, as I have found a specimen close to a nest, which contained both eggs and larvæ, and the zealous mother furiously bit at anything presented to her. The eggs are oval in shape, quite smooth, and yellowish white in colour. The young larva is drawn at Plate [I]., fig. 3a; it is remarkable for its superficial resemblance to a small Iulus, and being found in similar situations to that animal, its mimicry has probably some useful object. The older larva differs chiefly in having the head and thoracic segments proportionately smaller. Twenty-one closely allied insects belonging to two genera are described by Captain Broun in his Manual, the largest being Pterostichus australasiæ, which is found in similar localities to the present species, but is not so common.

Group Hydradephaga.

Family Dyticidæ.

Colymbetes rufimanus (Plate [I]., fig. 4, 4a larva).

This insect is found plentifully in all still waters during the summer months. Its larva is a soft elongate grub, provided with six slender thoracic legs, and a pair of powerful mandibles. The posterior extremity of the body is furnished with two curious appendages bearing a spiracle at the apex of each, which the larva frequently protrudes above the surface of the water. The air is taken in through the spiracles, and conveyed to all parts of the body by two main air-tubes, one of which springs from each spiracle, and branches throughout the insect in every direction. During the spring months the larvæ may be found of various sizes in similar situations to the imago; they are very voracious, devouring freshwater shrimps, Ephemera larvæ, and occasionally, when pressed by hunger, they will even destroy individuals of their own species for food. These they capture by means of their powerful mandibles, retaining a firm hold of the victim until they have consumed all the fleshy portions, the rest of the carcase being thrown aside, and a fresh search made for more. One individual I kept for some time, remained perpetually concealed in a small patch of green weed, growing in the middle of its aquarium. In a short time it became surrounded with the skeletons of small water shrimps which had been seized by the larva as they passed by its hiding place, the unfortunate crustaceans only discovering their enemy when it was too late. I have not yet observed the pupa of this insect, but it probably does not differ materially from those of its European allies. Although so very different in general appearance to the preceding insects, this beetle will be found on careful examination to agree with them in all important respects, being only what a ground beetle might naturally become if forced to lead an aquatic existence. Breathing is effected in all the water beetles by the spiracles of the abdomen, which alone are developed. The air is taken in between the elytra and the body, and owing to the convexity of the former, a supply can be retained sufficient to last the insect some twenty or thirty minutes. The beetles may be often observed with the extremity of their elytra protruded above the surface, renewing their supplies of air. On very hot days C. rufimanus may be occasionally seen flying with great rapidity far away from its native ponds. When doing so it makes a loud humming noise, and is a much more conspicuous object than when in the water.

Group Clavicornia.

Family Nitidulidæ.

Epuræa zealandica.

This curious little beetle is found abundantly in the neighbourhood of decaying fungi, throughout the year, being most plentiful in the autumn and early winter. Its larva is a small cylindrical grub, with the head and legs so minute that they are scarcely perceptible, causing it to closely resemble the maggots of many dipterous insects, occurring in similar localities. It is generally found in the large yellow fungi, so abundant in wet situations during the late autumn and winter months. It forms numerous galleries through the plant in all directions, and owing to the large amount of moisture which is usually present, these galleries are often filled with water, so that the insect may be said to be sub-aquatic in its habits. I have not yet detected the pupa of this species, although the discovery of a large quantity of both larvæ and perfect insects is of everyday occurrence with the entomologist in winter.

Family Engidæ.

Dryocora Howittii (Plate [I]., fig. 6, 6a larva).

This quaint-looking little insect occurs occasionally in damp matai logs, when in an advanced state of decay. The larva (Fig. 6a) is very flat and thin, possessing the usual thoracic legs, which, however, are rather short. The last segment of the abdomen is furnished with an anal proleg and a pair of small setiform appendages. Its mode of progression is very peculiar, resembling that of the Geometer larvæ among the Lepidoptera.

The thoracic legs are first brought to the ground, and the rest of the body is then drawn up in an arched position close behind them. The anal proleg then supports the insect while the anterior segments are thrust out, and the others follow as before. This method is only employed on smooth surfaces, the larva crawling along elsewhere in the usual manner.

The perfect beetle is a very sluggish insect, and difficult to find owing to its colour, which closely resembles that of the wood in which it lives.

Family Engidæ.

Chætosoma scaritides (Plate [I]., fig. 2).

This insect may be at once recognized by its peculiar shape, no other New Zealand beetle resembling it in this respect. Although tolerably common and generally distributed, it is very seldom seen abroad, spending almost the whole of its life concealed in the burrows of various wood-boring weevils. Its larva, which feeds on the grubs of these insects, is of a pinkish colour, very fat and sluggish; the head and three anterior segments are strong and horny, the legs being rather short. It undergoes its transformation into the pupa within the weevil burrows, when the limbs of the perfect insect can be seen folded down the breast, the wings and elytra being much smaller than in the beetle. Specimens in all stages of existence may be readily procured by splitting up old perforated logs which have been long tenanted by weevils.

Group Brachelytra.

Family Staphylinidæ.

Staphylinus oculatus (Plate [I]., fig. 5).

This is the New Zealand representative of S. olens or the "Devil's Coach Horse," one of the most familiar of British beetles. It is found occasionally in the neighbourhood of slaughter-houses, and may be at once distinguished from any of the allied species by a large spot of brilliant scarlet situated on each side of its head behind the eyes; this very conspicuous feature has given it the specific name of oculatus. I am at present unacquainted with the transformations of this fine insect, but they will probably closely resemble those of the typical species (S. olens) described in the majority of standard books on European Coleoptera. This beetle may be frequently seen flying in the sunshine, when it has a most striking appearance, owing to its large size and rapid motion. An unpleasant odour is found to arise when it is handled, this being noticeable in nearly all the members of the family. These beetles are comparatively numerous in New Zealand, the genus Philonthus comprising several elongate active insects, of which P. œneus is one of the commonest, and may be found abundantly amongst garden refuse. Others frequent the seashore, feeding on decaying seaweed, and may be noticed flying in all directions along the coast immediately after sundown. Another genus (Xantholinus) includes a number of interesting beetles found in old weevil burrows, and probably feeding on their inmates.

Group Lamellicornes.

Family Lucanidæ.

Dorcus punctulatus (Plate [I]., fig. 7).

An abundant species chiefly attached to the red pine tree or rimu, where it may be found concealed beneath the scaly bark, in the angles of the trunk near the roots. When disturbed, it folds up its legs and antennæ on its breast, and, extending its powerful jaws, awaits the approach of the enemy, ready to bite anything coming within its reach. These, however, are purely defensive measures, the insect being quite harmless when left alone. The larva is at present unknown to me. Another species, D. reticulatus, is a much handsomer insect than the preceding; it may be at once recognized by four deep impressions in the thorax, filled in with light-brown scales; the margins of the elytra are similarly scaled, as well as four spots on each elytron, the remainder of the beetle being dark-brown and shining. It is generally found in totara bark, but is much scarcer than the last species. One small specimen I possess, remarkable for its brilliant appearance, was taken under the bark of a stunted black birch tree, over two thousand feet above the sea-level.

Family Melolonthidæ.

Stethaspis suturalis (Plate [I]., fig. 8, 8a larva).

This conspicuous insect occurs abundantly in all open situations. Its larva (Fig. 8a) inhabits the earth, feeding on the roots of various plants, and is especially abundant in paddocks, where it occasionally does considerable damage to the grass, and threatens ere long to become as great a pest as its first cousin, the renowned Cockchaffer of England (Melolontha vulgaris), whose fearful ravages need no description. It may be taken as a typical larva of the family, the rest differing from one another in little else than size. When full-grown it is quite as large as the illustration, and is nearly always in the position there indicated, owing to the size of its posterior segments and the absence of any anal proleg, which compel it to lie always on its side. I have not yet succeeded in obtaining the pupa of this insect, although larvæ may be frequently found enclosed in oval cells, evidently about to undergo their transformation. Several of these have been kept in captivity, but they have hitherto always died without undergoing any change. I have, however, no doubt as to its being the larva of S. suturalis, as there are no other large Lamellicorns found near Wellington to which it could possibly be referred. The perfect beetle appears in great numbers from November to March; it is best taken at dusk, when it flies with a loud humming noise, about four feet above the ground. If knocked down it always falls amongst the herbage, and is not readily perceived until a few minutes later, when the humming noise is resumed as the insect again gets under weigh, and the would-be captor must not lose time if he wishes to secure it. Occasionally individuals are seen disporting themselves on the wing during the day, but this must be regarded as a purely exceptional circumstance. Unlike the majority of nocturnal Coleoptera, this insect does not appear to be attracted by light; in fact I have never obtained any specimens by this method, although most other night-flying beetles may be taken in goodly numbers at the attracting lamp.

Family Melolonthidæ.

Pyronota festiva.

This brilliant little insect is extremely abundant amongst manuka, during the early summer. In general appearance it reminds one of a miniature specimen of the last species, but is more elongate in form; the green thorax and elytra are also much brighter. The latter are bordered with flashing crimson, the legs and under surface being reddish-brown, sparsely clothed with white hairs. A small Lamellicorn grub, found amongst refuse in manuka thickets, is probably the larva of this insect; it is less thickened posteriorly than that of S. suturalis, but otherwise closely resembles it. The perfect insect is diurnal in its habits, flying round flowering manuka in countless numbers on a hot day. The descent of thirty or forty of these little beetles on to the beating sheet, out of a single bush, is of frequent occurrence, and is particularly noticed by the New Zealand entomologist accustomed to the meagre supply of specimens offered in the majority of instances.

Group Sternoxi.

Family Elateridæ.

Thoramus wakefieldi (Plate [II]., fig. 1, 1b larva, 1a pupa).

This fine beetle may be taken under rimu bark in tolerable abundance, and is often observed flying about at dusk during the summer. Its larva inhabits rotten wood, usually selecting the red pine, in which it excavates numerous flat galleries near the surface of the logs. When disturbed it is very sluggish, the head being immediately withdrawn into the large thoracic segment and completely concealed. The legs are very minute, and are of but little use in walking, the insect being chiefly dependent for locomotion on its large anal proleg, which is furnished with numerous horny spines. When full-grown this larva closes up one end of its burrow, and thus forms a closed cell, in which it is transformed into the pupa shown at Fig. 1a, remaining in this condition until the warmer weather calls the insect from its retreat. Two closely allied species are T. perblandus and Metablax acutipennis. The former is occasionally found under the large scales on matai trees, and resembles the present insect in general appearance, but is much smaller and more elongate in form, its elytra being also ornamented with longitudinal rows of yellowish-brown hairs. The latter may be often taken on the wing in the hottest sunshine, and is chiefly remarkable for its elongate prothorax and pointed elytra; its colour is dark reddish-brown, ornamented with a few scattered white hairs. All these insects possess the singular habit of leaping into the air when placed on their backs, the last-named species exercising this faculty in a most marked degree. The movement is effected by the joint between the pro- and meso-thorax, the sternum of the former being elongated into a long process, fitting into a corresponding cavity in the latter, so that by means of the two being suddenly brought together, the insect is thrown high into the air with a loud clicking sound, hence the English name of the Skipjack or Click Beetles, the scientific name, Elater, doubtless having reference to the same habit. The object of this curious arrangement is in all probability twofold; the sharp click and rapid movement of the insect deterring many enemies from attacking it, whilst the short legs of the beetle, which are quite unable to reach the ground when it is thrown on its back, render a special contrivance necessary.

Group Heteromera.

Family Tenebrionidæ.

Uloma tenebrionides (Plate [II]., fig. 2, 2a larva, 2b pupa).

One of our commonest beetles, found in great abundance in all moist wood when much decayed, the favourite trees being apparently rimu and matai. Its cylindrical larva may be taken in similar situations, and much resembles in general appearance the well-known "wire-worm" of England, whose destructive habits, however, it does not share. At present, whilst bush-clearing is going on, its influence is beneficial, as it devours large quantities of useless wood, which is thus rapidly broken up and got rid of. The pupa is enclosed in an oval cell, constructed by the larva before changing, from which the perfect insect emerges in due course. When first exuded its colour is pale red, but this rapidly changes into dark brown after the insect has been hardened by exposure to the air. Specimens are often met with of every intermediate shade, and are rather liable to deceive the beginner, who mistakes them for distinct species. An account of a small Dipterous insect infesting this beetle in its preparatory states will be found on page [62].

Group Longicornia.

Family Prionidæ.

Prionus reticularis (Plate [II]., fig. 3, 3b larva, 3a pupa).

This is the largest species of beetle found in New Zealand, and is common throughout the summer in the neighbourhood of forests. Its larva (Fig. 3b) is a large, fat grub, with minute legs; it inhabits rimu and matai, logs, often committing great ravages on sound timber although frequently eating that which is decayed; posts, rails, and the rafters of houses alike suffer from its attacks; the great holes formed by a full-grown larva of this insect creating rapid destruction in the largest timbers. It may be remarked, in connection with these wood-boring species, that a good thick coat of paint put on the timber as soon as it is exposed, and renewed at frequent intervals, to a great extent prevents their attacks. The pupa (Fig. 3a) is enclosed in one of the burrows formed by the larva, which, before changing, blocks up any aperture, so as to rest secure from all enemies. The perfect insect emerges in the following summer, when it may be often observed flying about at night. It is greatly attracted by light, and this propensity frequently leads it on summer evenings to invade ladies' drawing-rooms, when its sudden and noisy arrival is apt to cause much needless consternation amongst the inmates.

Closely allied to the above is Ochrocydus huttoni, which may be at once known by its smaller size and plain elytra; it is very much scarcer than P. reticularis, but may occasionally be cut out of dead manuka trees in company with its larva.

Group Rhyncophora.

Family Curculionidæ.

Oreda notata (Plate [II]., fig. 4, 4a larva).

This weevil is not often noticed in the open, but may be found in great abundance in the dead stems of fuchsia, mahoe, and other soft-wooded shrubs, whose trunks are frequently noticed pierced with numerous cylindrical holes. The larva also inhabits these burrows, devouring large quantities of the wood; it is provided with a large head and powerful pair of mandibles, but, in common with all other weevil larvæ, does not possess legs of any description, the insect being absolutely helpless when removed from its home in the wood. The pupa might also be found in similar situations, but I have not yet observed it. The perfect insect may be cut out of the trees throughout the year, and is occasionally taken amongst herbage during the summer.

Family Curculionidæ.

Psepholax coronatus (Plate [II]., fig. 5 ♀, 5a ♂).

This curious species is found abundantly in the stems of dead currant trees (Aristotelia racemosa), in which it excavates numerous cylindrical burrows like the last species, which it closely resembles when in the larval state. The sexes are widely different, the elytra of the male being furnished with the characteristic coronet of spines, which is entirely wanting in the female. Numerous other members of this genus may be taken in company with the present insect, and should be carefully examined, as a correct determination of the males and females of the several species is sadly wanted. Digging beetles out of the wood is good employment for the entomologist in winter, when he will find that a day spent in this manner will frequently produce as rich a harvest as one in the height of summer.

Before finally leaving the Coleoptera, I should like to direct the attention of my readers to the immense number of interesting weevils found in New Zealand. Chief among these is the remarkable Lasiorhynchus barbicornis, a large insect furnished with a gigantic rostrum, which will at once distinguish it from any of the rest. Other genera contain numerous beetles, which may be found in various kinds of dead timber in company with their larvæ, and are worthy of a more minute investigation than has at present been given them.

CHAPTER IV

The Hymenoptera are perhaps the most interesting order of insects, their brilliant colours, great activity, and unparalleled instincts rendering them alike attractive to the young collector and scientific entomologist. They are, however, not very numerous in New Zealand, several of the most important families being completely absent; in fact, with the exception of the ants, there are no social Hymenoptera native to this country. The information I here give in connection with these insects does not adequately represent the large amount of interest which can be derived from their investigation, and I must therefore refer the reader to those admirable works by Sir J. Lubbock on Ants and by Huber on Bees, which cannot fail to interest all who read them.

Family Andrenidæ.

Dasycolletes hirtipes (?) (Plate [III]., fig. 1).

This is the true native bee of New Zealand, and may be taken abundantly during the whole of the summer. Its nest is constructed in crevices in the bark of trees, &c., the insect very frequently selecting the spaces between the boards of outhouses, where the loud buzzing noise made by the perfect bees when emerging from their retreat at once arrests our attention. These nests consist of about ten oval cells, formed of clay, and neatly smoothed within. They are all constructed by a single female, which also provisions them with honey and pollen, depositing an egg in each. The larva, after consuming the food, changes into a pupa, from which the perfect insect emerges about January. If the reader will imagine a great number of these nests closely packed together, the formation and storing of the cells being performed by a number of sterile individuals (workers), while the eggs are deposited by a single female (queen), he will have a fair idea of the economy of the social bees and wasps, whose wonderful instincts attain their maximum in the well-known hive-bee, successfully introduced and cultivated in various parts of the country.

Closely allied to this species is Dasycolletes purpureus (?) (Fig. 10), which forms its nests in sand-banks, its cylindrical holes having a great resemblance to the burrows of Cincindela tuberculata, which frequently occur in the same situation.

Family Sphegidæ.

Pompilus fugax (Plate [III]., fig. 2).

This is a very abundant insect, and may be observed flying about on any fine day during the summer, occasionally stopping to examine leaves and crevices in the bark of trees, where it is looking for the unfortunate spiders, which constitute the food of its progeny. The larva is a fat apodal grub, and may be found in the cells constructed by the perfect insect, which usually selects a large cylindrical hole in a log, previously drilled out by a weevil. Into this burrow she pushes a large quantity of spiders, which she has previously captured and paralyzed with her venomous sting. When her nest is properly provisioned she deposits an egg in it, closes the hole with a neat plug of clay, and leaves the larva to quietly consume its half-dead companions. Each female, no doubt, forms a large number of these cells during the summer. While cutting up old logs for Coleoptera, the entomologist will not infrequently come across these nests, when the insects may be found in various stages of development. Unfortunately, however, the sight which usually meets his eye is a large number of legs and other fragments of spiders, the fugax having long since deserted the burrow, and being very probably engaged in forming others in a neighbouring tree. These insects are very ferocious, and will attack spiders which considerably exceed them in size. On one occasion I noticed a very large one at rest in the centre of its web, which was suddenly noticed by a passing fugax, which immediately sprang upon its back, and, in spite of violent movements on the part of the spider, twisted her abdomen dexterously round and stung her victim in the centre of the thorax, between the insertions of the legs. This produced almost instantaneous paralysis in the spider; but it was apparently too large for the fugax to carry away to her nest, as I saw the unfortunate creature hanging helplessly in its web some hours after the occurrence.

Family Formicidæ.

Formica zealandica (Plate [III]., fig. 3 ♂, 3a ♀, 3b ☿, 3c, cocoon).

This is one of our commonest ants, and may be noticed under logs and stones throughout the year. The nest consists of a number of irregular cavities dug out by the workers either in the ground or in soft rotten wood. Its size varies considerably, but the societies of this species are not usually so extensive as those of Atta antarctica, an insect I shall have occasion to refer to presently. The larvæ are minute apodal grubs, which are dependent entirely on the workers for food. When full grown they spin an oval cocoon of white silk, in which they are converted into pupæ, and these the patient neuter ants may be observed carrying away with great anxiety when disturbed, risking their own lives to preserve their adopted offspring from destruction. The females, or queens, of which there are several in each nest, do not appear to participate in these labours, but are only instrumental in perpetuating the species, and the same remark applies to the males. A large number of these winged males and females may be observed in the nests about February, the general emergence taking place during that month. At this time they leave their native homes and mount to a great height in the air, and after sporting for some hours they re-alight on the earth, and in a short space of time cast their wings. The neuters at this time are said to carry them away to form fresh colonies, but I have not carried my investigations sufficiently far to verify this in connection with the New Zealand species.

Family Formicidæ.

Ponera castanea (Plate [III]., fig. 4 ♂, 4a ☿, 4b, larva).

This is a much larger species of ant than the last, but is apparently not unlike it in habits. I have figured a male (Fig. 4) and worker (4a), the female not differing from the latter in any great degree, except in being provided with wings. It will be noticed, however, that the male is very divergent. The larvæ of this insect are covered with numerous minute spines, and may be often found in the nests; also the cocoons which they form when full grown, these latter being of a dark brown colour, and rather elongate. The winged insects are not frequently seen. They appear only for a short time in February, the earlier ones being invariably held captive by the workers until the rest have emerged, when they are all allowed to fly away and form fresh colonies as in the last species.

Family Formicidæ.

Atta antarctica (Plate [III]., fig. 5 ♂, 5a ♀, 5b, larva).

This is another very abundant species, found occasionally amongst rotten wood in very large communities. Its larva, which is represented at Fig. 5b, does not form any cocoon, the pupa being quite naked and defenceless. It is a beautiful little object when examined with a microscope of moderate power. The annual migration of the winged males and females of this species usually takes place on a hot day in the last week of March, at which time I have observed the air throughout a day's journey absolutely swarming with these little insects. Many specimens are captured in the spiders' webs, while the logs, fences, and ground are covered with ants in the proportion of about ten males to one female. At other seasons of the year the winged individuals of Atta antarctica are seldom observed.

Family Chalcididæ.

Pteromalus sp. (?) (Plate [III]., fig. 9).

This little insect was reared, in company with thirteen others of the same species, from a pupa of Eurigaster marginatus which had been procured from a larva of Œceticus omnivorus, and is consequently a true hyperparasite.[^[3]] Its curious habits will be better understood by the reader after perusal of the life-histories of those two insects, which I have given on pages [60] and [74]. The method by which the females of the Hymenoptera whose larvæ are parasitic on insects inhabiting other insects, introduce their eggs into their hosts,[^[4]] is not at present known to entomologists, but it seems at least probable that they are deposited in the eggs of the parasitic Dipteron before these gain access to the caterpillar of the moth.

Family Ichneumonidæ.

Ichneumon sollicitorius (Plate [III]., fig. 6).

This is the most abundant of our ichneumon-flies, and may be taken amongst herbage from August till May. Its larva is parasitic in the caterpillars of various Noctuæ, having occurred in the following species: Mamestra composita, M. mutans, and M. ustistriga. The pupa may be frequently discovered inside that of the moth, and is quite white in its early stages, but as age advances all the colours of the future insect can be seen through the thin pellicle which invests it. The perfect insect makes its escape through a circular hole, which it drills in the upper end of the unfortunate moth pupa it has destroyed. The sexes of all ichneumon-flies may be at once recognized by the females possessing an ovipositor[^[5]] differing considerably in length among the various species, but nearly always plainly visible.

Family Ichneumonidæ.

Ichneumon deceptus (Plate [III]., fig. 7).

This conspicuous insect is chiefly mentioned on account of a very curious habit possessed by the females of congregating in large numbers on matai trees, as many as fifty or sixty specimens being often found huddled together under a single flake of the bark. The males are occasionally taken flying in the open, but I have never seen any amongst these large assemblages of females. Whether the ichneumons are parasitic on some insect which lives on the matai, or whether they assemble to feast on the sweet juice occasionally exuded from its bark, it is impossible to say, but in either case the complete absence of males is a very remarkable circumstance.

Family Ichneumonidæ.

Scolobates varipes (Plate [III]., fig. 8).

The larva of this little insect is parasitic on the useful larva of Syrphus ortas whose life-history is recorded on page [57]. It is very common in some instances, and must consequently destroy a considerable number. It entirely eats the soft portions of the insect, and may afterwards be found lying snugly within the hard empty shell of the deceased syrphus pupa, which acts as a cocoon for it while undergoing its own pupa state. The perfect insect may be often observed amongst herbage, searching for syrphus larvæ to deposit its eggs in.

CHAPTER V

The next Order which comes under review is the Diptera, which includes all the two-winged insects, and constitutes a most extensive Order in respect to the number of distinct species. When, however, the numbers of individuals of the same species are considered, it is probable that this Order includes a greater proportion of the insect-world than all the others put together. The preponderance of these insects over the rest holds good with greater force in New Zealand than in many other countries, and this fact may be almost inferred from the large number of spiders present here, which are chiefly dependent on Diptera for their support. The important function of clearing away refuse matter is almost entirely performed by the members of this Order, as the Necrophagous Coleoptera and other scavengers which exist in such large numbers in many countries are practically absent here, and their work consequently devolves upon dipterous insects.

Group Nemocera.

Family Culicidæ.

Culex iracundus (Plate [IV]., fig. 1, 1a larva, 1b pupa).

The mosquito is only too familiar to every one from its ceaseless attacks; it occurs almost everywhere, but is most abundant in marshy situations. The larva (Fig. 1a) inhabits all stagnant waters, where it may be found very abundantly throughout the summer, and when disturbed it plunges about with great agility. Its food consists of the numerous animalculæ swarming in all still waters during the greater portion of the year. These are captured by means of two curious anterior appendages, which are fringed with long hair, and pulled through the water like a fisherman's net; they are then withdrawn into the mouth and the contents devoured, the hungry insect again extending them for a fresh supply. These larvæ are generally seen suspended from the surface of the water by the curious air-tube which takes its rise from the penultimate segment of the abdomen, which is of considerable length. Its apex is armed with a row of stiff bristles, which effectually prevent the water from entering the spiracle there situated, so that the insect is enabled to respire when hanging from the surface, independently of any muscular action. It is also worthy of note that the intestine discharges itself into this tube, an arrangement which does not exist among the British species. After several moultings the transformation to the pupa state takes place. At this stage the insect (Fig. 1b) becomes much thickened anteriorly, this being the region of the head and thorax of the future gnat; all the limbs are easily detected on a close examination, as with lepidopterous pupæ. The upper portion is provided with two short appendages, fulfilling the same function as the air-tube of the larva, and which constantly support the pupa at the surface of the water. The terminal fins enable it to dash through the water with great rapidity when pursued by enemies; at other times it remains perfectly motionless, suspended from the surface of the water. It should be mentioned that none of these aquatic pupæ take any nourishment, neither have they any limbs properly so called. Their locomotion, although in some cases unquestionably rapid, is entirely effected by violent motions of the abdomen. I have been careful to point out these peculiarities as these animals have been regarded by many authors as active pupæ on a level with those of the Orthoptera and Hemiptera. This opinion, however, is manifestly erroneous; the pupæ of the nemocerous Diptera are on precisely the same footing as those of the Lepidoptera, and it would be almost as reasonable to call one of these active, because it wriggles out of its cocoon in the earth before the emergence of the moth. The perfect mosquito emerges from a rent in the thoracic shield of the pupa, drawing each pair of legs out separately, and placing them in front of it on the water; the wings and abdomen are then extracted and in a few moments it flies away.

The bites of these insects appear to distress some people much more than others, probably owing to constitutional differences. I should mention that the females alone engage in these attacks, the males being quite harmless and subsisting entirely on honey, which is doubtless the natural food of both sexes. The male and female mosquito are readily distinguished, the specimen figured belonging to the latter sex; her companion is chiefly remarkable for his plumed antennæ and beautiful palpi, which are very long and gracefully plumed. As many of the harmless insects which will be investigated are often mistaken for this species, and destroyed accordingly, I should like to advise my readers that they may at once distinguish all the venomous species of gnats by their long, lancet-like proboscis and loud humming noise during flight.

Closely allied to this insect is Culex argyropus, which might be called the coast mosquito as it is always found near the seashore, its larva living in brackish pools just above high-water mark. The perfect insect may be also seen skating along the surface of the water like a gerris[^[6]]; it may be at once distinguished by its dark colour,.

Family Tipulidæ.

Corethra antarctica, n.s.[^[7]] (Plate [IV]., fig. 3, 3a larva, 3b pupa).

An elegant little gnat, frequenting the margins of ponds and ditches during the spring months. The larva (Fig. 3a) is bright green, ornamented with numerous yellow spots; it is very sluggish, living in the green slime weed which floats on the water in such large masses during that season. Not being very common it is difficult to find, as its colour so closely resembles that of the weed which it always frequents. The pupa (Fig 3b), is not very agile, and is nearly always observed suspended from the surface by its thoracic air-tubes and caudal fins, the abdomen being directed upwards and thus bringing the two pairs of organs close together. In its metamorphosis and general appearance this insect forms a convenient link between the present family and the Culicidæ.

Family Tipulidæ.

Chironomus zealandicus, n.s. (Plate [IV]., fig. 2, 2a larva, 2b pupa).

This is the common midge of New Zealand, and is extremely abundant throughout the country. Its larva (Fig. 2a) inhabits the soft mud at the bottom of stagnant ponds and streams, and is very conspicuous, being of a brilliant crimson colour and thus much resembling the well-known "Bloodworm" of English anglers, which is the larva of a closely allied European species (C. plumosus). It may be readily kept in an aquarium, and if supplied with a little soil and green weed will rapidly cover the walls of its glass prison with numerous tubular galleries. These take their rise from the mud at the bottom, and, extending upwards to a distance of three or four inches, afford the larva a convenient retreat from all enemies. These insects are occasionally seen swimming laboriously through the water with a peculiar zigzag motion. When out of their burrows they have considerable difficulty in keeping beneath the surface, and may be often observed floating helplessly with their exposed portions quite dry; in fact the whole integment of the insect appears to have a peculiar power of resisting the water. The pupa (Fig. 2b), is a most beautiful object, its anterior extremity being obtusely thickened and the limbs of the future insect quite discernible. On each side of the thorax the gills form a set of graceful plumes, a much smaller group being also situated at the extremity of its abdomen. In this state the insect remains almost entirely concealed in the burrows previously constructed by the larva, its gills imbibing sufficient air from the surrounding medium, and thus rendering ascension to the surface unnecessary. The water is periodically circulated in the tunnels by violent movements on the part of the pupa. About a day before emergence the insect assumes a peculiar silvery appearance, which is occasioned by the presence of a large quantity of air between the imago and its pupa skin. This air has been first imbibed by the gills and afterwards expelled through the spiracles of the enclosed gnat, thus inflating the skin of the pupa, and helping to buoy it up during its last and most important transformation. Leaving its tunnel the insect rises to the surface, the thorax is lifted above the water which retreats from it on all sides, the skin cracks open at the back and the insect slowly extricates itself in a similar manner to the mosquito. In about ten minutes' time the wings are sufficiently hardened for use and the insect then flies ashore, but we may occasionally notice, beside their old pupa-skins, drowned individuals which have failed to effect a successful emergence. The perfect insect is extremely common in all swampy situations throughout the summer; it has a great partiality for light, and may be occasionally noticed in vast numbers round the street lamps on a hot summer's night, especially if rain is impending. It is a most graceful insect, and will amply repay a minute examination (Fig. 2).

Family Tipulidæ.

Ceratopogon antipodum, n.s. (Plate [IV]., fig. 4, 4a larva, 4b pupa).

Very plentiful in the forest throughout the year, often enlivening the winter sunshine by its merry gambols. The larva (Fig. 4a), is found under the bark of newly fallen trees, feeding on the sap which exudes in large quantities from the logs whilst drying. When first discovered it often has a curiously spangled appearance, owing to the minute beads of moisture retained by numerous bristles clothing the larva. When about to change, these insects assemble in large companies of thirty or forty, firmly affixing their basal segments to the wood, their heads all pointing inwards and forming a small circle. In some cases, where an unusually large gathering has occurred, a number arrange themselves into an outer row, their heads being immediately behind the extremities of the inner group, the whole thus bearing a rough likeness to the radiations of a star-fish. The pupa is very short, and is furnished with two clubbed horns on the thorax for respiration. Its abdominal portions are retained within the old larval skin, thus keeping it firmly anchored to the log. The perfect insect emerges from a rent in the thorax of the pupa, groups of exuviæ being of common occurrence under the bark. The sexes differ considerably, the individual figured (Fig. 4) being a male; the female is slightly larger, and much more stoutly built; her antennæ are filiform[^[8]], and the limbs generally shorter. Both are equally common, but the male is more often noticed, owing to his greater activity.

Family Tipulidæ.

Psychoda conspicillata (Plate [IV]., fig. 6).

A common species, occurring plentifully on window panes during August, and bearing a great superficial resemblance to a small moth of the Tineina group, often deceiving the novice in consequence. It is a beautiful object for the microscope, the figure being a careful drawing of the insect, seen with a power of about ten diameters. I regret to say that its transformations are at present unknown.

Family Tipulidæ.

Mycetophila antarctica, n.s. (Plate [IV]., fig. 5, 5a larva, 5b pupa).

Tolerably common in the vicinity of forest during the major part of the year. The larva (Fig. 5a), is a small elongate maggot of a pinkish colour; it is a social insect, inhabiting rotten pine logs, which it perforates with numerous cylindrical burrows. These larvæ, entirely confine their attention to damp wood of a "pappy" consistency, leaving the harder logs for the wood-boring Coleoptera, which are provided with much stronger jaws. They consequently do not injure the rafters and boards of houses, or other valuable timbers. The pupa (Fig. 5b) is very elongate, reposing in one of the burrows, previously constructed by the larva. It probably breathes by means of its spiracles, as no special organs of respiration are visible. The perfect insect appears in a short time, flying sluggishly in the sunshine, the female possessing an enormous abdomen, which almost incapacitates her for aerial locomotion; in other respects she resembles the male, which is the sex figured (Fig. 5).

Family Tipulidæ.

Tipula holochlora (Plate [V]., fig. 1, 1a larva, 1b pupa).

This beautiful insect is very common in the forest throughout New Zealand. Its larva (Fig. 1a) inhabits various kinds of decaying wood, frequently occurring in vegetable refuse at the roots of trees. It is a large, sluggish-looking grub, and the anterior segments are very retractile. Its colour appears to vary according to its surroundings, those specimens found in red pine being of the dull reddish hue characteristic of that wood, while those taken from pukatea and henau are dark brown larvæ, resembling the illustration. These insects are very voracious, but their growth is gradual, each larva probably occupying at least six months to reach maturity. They mostly feed during the winter, but may be often taken at other times. The pupa (Fig. 1b) is enclosed in a small oval cell, previously excavated by the larva, which also constructs a ready means of escape for the future insect in the form of a small tunnel leading out of one end of its prison to the open air. Through this the pupa wriggles, assisted by the spines, which arm the edges of all the segments; the coronet of hooks at its extremity retaining the insect firmly at the mouth of its burrow while undergoing its final transformation. After numerous twistings and contortions on the part of the pupa, a rent is formed in the thoracic plates, and the imago draws itself out, standing on the log until its wings are sufficiently hardened for flight. In many old houses numbers of these exuviæ may be seen projecting from holes in the boards—a relic of the destruction that has taken place within. These insects naturally inhabit dead trees, but as they will devour unsound timber in any form they are very injurious to old wooden buildings. The perfect insect chiefly frequents forest, where it is difficult to detect owing to its green colour harmonizing so closely with the leaves. The specimen figured (Fig. 1) is a male, the female being considerably smaller with a much stouter body and shorter legs.

Family Tipulidæ.

Tipula fumipennis, n.s. (Plate [V]., fig. 2, 2a larva, 2b pupa).

Another fine species, occurring in similar situations to the last, but not quite so commonly. The larva (Fig. 2a) may be found throughout the year under the bark of very rotten henau and pukatea, feeding on the moist decaying wood. It constructs in this material numerous burrows, which are lined with a viscous fluid constantly emitted from the mouth. Its movements in these are very rapid, frequently eluding the most careful searches. When divested of its slimy covering, it is anything but an offensive-looking larva, the great air-tubes, which run the whole length of the insect, being very conspicuous, and many of the other internal organs are easily detected owing to its partial transparency. The pupa (Fig. 2b) is enclosed in a small cocoon, having ready access to the air; it is chiefly remarkable for its very large thoracic horns, which are curiously toothed. The air-tubes connected with these are distinctly visible in the abdomen of the insect, where they may be seen branching in all directions. When about to emerge this pupa works its way to the surface of the log, the head and thorax are thrust outside, and the perfect insect escapes in the ordinary way. The illustration (Fig. 2) is taken from a female; the male differs in being less robust, and in being provided with longer legs.

Family Tipulidæ.

The Glow-worm. Bolitophila luminosa, Skuse.

([Frontispiece], fig. 1).

Every one who has walked in the forest at night has no doubt noticed, in many damp and precipitous situations, numerous brilliant points of greenish white light shining out from amongst the dense undergrowth. The animal which causes this light may be seen at Fig. 1a on the Frontispiece, and is probably one of the most interesting insects we have in New Zealand. It inhabits irregular cavities, mostly situated in the banks of streams, where it hangs suspended in a glutinous web which is stretched across the cavity and supported by several smaller threads running right and left, and attached to the sides and ends of the niche. On this the larva invariably rests, but when disturbed immediately glides back along the main thread and retreats into a hole which it has provided at the end of it. From the lower side of this central thread numerous smaller threads hang down, and are always covered with little globules of water, constituting a conspicuous, though apparently unimportant, portion of the insect's web. It should be mentioned that all these threads are constructed by the larva from a sticky mucus exuded from the mouth.

The organ which emits the light can easily be seen by referring to Fig. 1a. It is situated at the posterior extremity of the larva, and is a gelatinous and semi-transparent structure capable of a great diversity of form. It can be extended or withdrawn at the will of the larva, which, however, can shut off the light independently of this latter action. Larvæ cease to shine on very cold nights, in the daytime, and in a room which is artificially lighted. They gleam most brilliantly on dark, damp nights, with a light north-west wind. These larvæ appear to suffer great mortality in a state of nature, as the young ones will always be found greatly in excess of those that are approaching maturity.

When full-grown this insect is transformed into the curious pupa shown at Fig. 1b. It is furnished with a large process on the back of the thorax which is attached to the web and holds the pupa suspended in the middle of the niche previously inhabited by the larva. The light is emitted from the posterior segment of the pupa, but is much fainter than in the larva, and a distinct organ is not apparent. It is frequently suppressed for days together.

The perfect insect is drawn at Fig. 1. It emits a strong light from the posterior segment of the abdomen, about half as bright as that emanating from a full grown larva. It has been recently described by Mr. Skuse, of Sydney, as Bolitophila luminosa.

During the whole course of my observations[^[9]] on this insect, extending over five years, I have only succeeded in bringing two specimens to maturity, and both of these were females.

The uses of the light and the web to the larva are at present quite unknown to me, as well as its food, which, however, possibly consists of fungi. It should also be mentioned that the larvæ are found in the greatest abundance in mining tunnels, many feet below the surface of the earth, as well as in caves.

Family Tipulidæ.

Cloniophora subfasciata (Plate [V]., fig. 3, 3a larva).

Tolerably common in damp gullies during summer and autumn. The larva (Fig. 3a) inhabits decayed henau logs, drilling deep into the wood, where its burrows are seldom noticed, as they are filled up with refuse almost as soon as they are made. The pupa resembles that of Tipula holochlora, but is rather more attenuated in the body, and the thoracic horns are slightly thicker. It is not enclosed in any cocoon, but lies amongst the powdery wood, wriggling to the surface when about to emerge. The illustration represents the male insect, the female having a much stouter body, with short thick legs; she also differs in her antennæ, which are much less branched than those of the male.

Family Tipulidæ.

Rhyphus neozealandicus (Plate [V]., fig. 4, 4a larva, 4b pupa).

A most abundant species occurring in most damp situations throughout the year. Its larva (Fig. 4a) closely resembles a small worm, being of an elongate form attenuated at each end. The skin is very hard and of a dull yellow colour, with black markings. The food of this insect consists of decaying vegetable matter, which it procures by means of two small appendages, situated on each side of the mouth, and which it is continually moving about in search of suitable materials. The pupa is a curious object (Fig. 4b), the two little respiratory horns having a singular resemblance to a pair of ears. It is enclosed in a small oval cell about one inch below the surface of the earth, the insect working its way to the air before emergence. The perfect Rhyphus may be almost regarded as one of our domestic insects, and is seldom found in the open country, but frequents cowhouses and other farm buildings in great numbers, the larvæ feeding on the manure in these situations. It is often mistaken by ignorant people for the mosquito and at once destroyed, but quite unfairly, as the species is in reality perfectly harmless, frequently benefiting mankind by the removal of considerable quantities of effete matter, which if allowed to remain could not fail to be injurious.

Family Tipulidæ.

Bibio nigrostigma (Plate [V]., fig. 5, 5a larva, 5b pupa).

This insect is very abundant during the spring months, but rapidly disappears, and few specimens are noticed after Christmas. Its larva (Fig. 5a) inhabits the woody powder often found under logs, which frequently consists of the accumulated excrement of wood-boring insects. It is gregarious in its habits, being found in large companies of fifty or a hundred individuals. When first disturbed these appear as a wriggling mass, but very shortly become so still that they can only be distinguished with the greatest difficulty from morsels of bark. A considerable portion of the powdered wood is also retained on the body of the insect by a row of short spines situated in the middle of each segment, which helps to render the larva still more inconspicuous. In this condition it remains for at least eight months, during which time growth takes place very slowly. About September the larvæ separate, each being afterwards transformed into a small yellowish pupa (5b), whose abdominal extremity is usually retained within the old skin, thus closely resembling that of the genus Ceratopogon. I have figured this pupa entirely naked, in order to show its characteristics, some of which are rather remarkable, more completely, the agglutination of nearly all the anterior portions of the body being especially noteworthy. The perfect insects may be found everywhere, the males sucking honey from the flowers and performing many antics in the air, often clinging hold of one another and whirling about together. The female seldom flies, but is usually observed crawling about fences or the trunks of trees. She may be at once recognized by her heavy body which is very large when distended with eggs. Her general colour is dull red, thus differing widely from the male insect represented in the illustration (Fig. 5).

Family Tipulidæ.

Simulia australiensis (Plate [VI]., fig. 1, 1a larva, 1b pupa).

Every one knows the sandfly, the little black insect that so persistently perches on our hands and faces and inflicts its painful punctures, which in many cases are followed by large swellings, often lasting for several days and causing much irritation. Its larva (Fig. 1a) inhabits clear running water, climbing about in strong currents by means of a pair of suckers situated at each end of the body, two being placed on the prothoracic segment just behind the head and two others close to the anal extremity. These the insect employs rather curiously, the anterior pair being first affixed and the others drawn up close behind them, its elongate body consequently forming a loop. Clinging by the posterior suckers for a moment the larva then reaches forward, re-affixes the anterior ones, and draws up the posterior as before. Breathing is performed by two spiracles situated on the last abdominal segments near the hind pair of suckers. Two large air-tubes originate from these and run forwards, giving off branches to all parts of the body; they terminate in a number of air-sacs in the thorax. The food of this larva consists of animalculæ, which are no doubt obtained by drawing the two ciliated appendages rapidly through the water several times in succession, their contents being afterwards gathered up by the smaller organs and passed into the mouth. When about to assume the pupa state the insect covers itself with a glutinous envelope, which is firmly joined to the under side of a leaf, the transformation taking place within a few days. The pupa can hardly be distinguished from a small moth chrysalis except for a pair of branching filaments, which arise from the top of the thorax and serve the purpose of gills (Fig. 1b). Before emergence the anterior segments are projected nearly out of the cocoon from which the perfect sandfly makes its escape, and floating to the surface of the water ascends the stem of an aquatic plant to expand its wings. I should here remark that as with the mosquitoes, the bloodthirsty propensities of the present species have no doubt been acquired since the arrival of man and other warm-blooded animals.

Group Brachocera.

Family Tabanidæ.

Tabanus impar (Plate [VI]., fig. 6).

I have figured this fine species as a representative of a most important family of Dipterous insects, but am at present quite unacquainted with its life-history. It occurs plentifully on the margins of the forest throughout the summer.

Family Bombylidæ.

Comptosia bicolor (Plate [VI]., fig. 2).

This conspicuous species is very abundant in glades throughout the summer, flying with great rapidity, and delighting to suck honey from the numerous shrubs which are in blossom at that time of year. It is a social species, and is usually found in companies of fifteen or twenty individuals, which engage in endless dances, two insects often seizing one another on the wing and then revolving together like a wheel in rapid motion. Their manœuvres in avoiding the strong gusty wind, so often prevalent in early summer, are also interesting; the insects play upon the wing whilst the air is quiet, but if a breeze springs up they instantly settle on the nearest bush, rising to renew their sports when it is again calm. These flies are rather variable in colour, some specimens being dark brown, whilst others are more or less covered with greyish-white hairs; individuals are also often met with quite black and shining, their hirsute covering having been completely rubbed off. The female may be at once recognized by her solid, fleshy abdomen, that of the male being inflated by two great air-bladders, which cause that portion of the body to appear semi-transparent when the insect is held up to the light. The figure (2) is taken from a specimen of the latter sex.

Closely allied to the present insect is Comptosia virida, n.s. (Fig. 3), which can be at once distinguished by its brilliant green eyes and pale grey clothing. The larva of this species is a large white maggot, rather robust, and possessing a small head. It inhabits the dense moss growing on the trunks of trees in the forest, feeding on the roots of these plants, and finally forming an oval cocoon, in which it changes into the pupa shown at Fig. 3b. The perfect insect appears in a few weeks' time, when it may be taken in similar situations to C. bicolor, but in much fewer numbers.

Family Asilidæ.

Sarapogon viduus (Plate [VI]., fig. 4, 4a larva, 4b pupa).

A voracious insect, frequenting all dry sand-banks and pathways throughout the summer, and destroying the numerous minute diptera found in those situations. These unfortunate victims are drilled through the thorax by their destroyer, which sucks them completely dry with its long beak-like proboscis. The larva (Fig. 4a) inhabits rotten wood, chiefly feeding upon the moist, powdery portions. It is usually somewhat sluggish, but when disturbed hops about with electrical rapidity. The head is very minute, and the elongate body consists of twenty segments, a number very unusual among larvæ, the normal number being twelve exclusive of the head. It lives for a considerable time and is finally transformed into the blunt-looking pupa, drawn at Fig. 4b, without having previously constructed any cocoon. From this the perfect insect emerges in a month or six weeks' time, commencing its work of destruction as soon as its wings are hardened, which takes place within a few hours.

Family Stratiomidæ.

Exaireta spiniger (Plate [VI]., fig. 5).

Abundant during November, when it may be taken in great numbers in the vicinity of water. The larva is probably aquatic, but I have not yet observed it, although its habits would, no doubt, be very interesting. The perfect insects frequent flowers, and are generally very sluggish in their movements.

Family Acroceridæ.

Acrocera longirostris, n.s. (Plate [VII]., fig. 4).

An extraordinary and very rare species, occurring amongst white rata[^[10]] blossoms in February. At present I have only taken three specimens, viz., two in Wellington and one in Nelson. The transformations of all the Acroceridæ are as yet unknown.

Family Syrphidæ.

Syrphus ortas (Plate [VII]., fig. 3, 3a larva, 3b pupa).

Very common everywhere from September till May, or even later, when specimens may be often seen basking in the winter sunshine. The larva (3a) is a most useful insect to gardeners as it destroys an immense number of aphides, those noxious little insects that commit such fearful ravages on many valuable plants (see Hemiptera, page [120]). In general appearance this larva resembles a small green slug, with the skin much wrinkled, and bearing at its extremity a short thick tube, which is probably the respiratory apparatus, the four lunate holes situated at its apex being no doubt the spiracles. These insects grow very slowly, occupying several weeks to attain maturity. Their mode of capturing the aphides is very curious, and is, briefly, as follows:—The larva lies in the midst of a number of aphides, and it occasionally happens that some of them crawl over it. On feeling an aphis touch its back the larva instantly darts out its long, pointed head and strikes its prey with the apex, which is enveloped in a quantity of very sticky mucus constantly ejected from the mouth. On the aphis being thus captured the larva withdraws its head into the hinder segments of its body and devours all the juicy portions of the aphis, whose dry skin is afterwards thrown aside. When full-grown it slowly shrinks up and changes into the pupa shown at Fig. 3b. In this state it is not protected by any kind of cocoon, but lies amongst the refuse of the aphides, near the stem of the plant. The fly emerges in a fortnight or three weeks' time, and is very fond of hovering over and sucking honey from the flowers, but the females may be often noticed running about plants, probably in search of a suitable place to oviposit.[^[11]] For an account of Scolobates varipes, a species parasitic on the present insect, I refer to page [39].

Family Syrphidæ.

Eristalis cingulatus (Plate [VII]., fig. 2).

This conspicuous insect occurs occasionally in glades in the forest about January, but is by no means common. It is very fond of the white rata flowers, where it may be taken, if anywhere. Its life-history is at present unknown, but no doubt resembles that of the following insect.

Family Syrphidæ.

Helophilus trilineatus (Plate [VII]., fig. 1, 1a larva, 1b pupa).

This fine species occurs abundantly in all damp situations throughout the summer. Its larva may be found in stagnant pools and is often met with in the mud at the bottom of ditches. Its posterior segments are enormously elongated, forming a telescopic breathing apparatus, composed of two tubes, the smaller of which is capable of being more or less extended at the will of the larva, which is thus enabled to adjust the length of its breathing tube, according to the depth of water or mud in which it happens to reside. This peculiarity has given all these larvæ the name of rat-tailed maggots. The other segments are very stout, each being furnished with a pair of minute feet, and the head is also provided with two small appendages which are supposed to be the outlets through which the exhausted air is discharged by the larva. When mature this insect leaves the water, forming a small oval cell in the neighbouring moist earth, in which it lies with its long tail folded along the breast. The skin then gradually hardens, and it is finally transformed into the pupa shown at Fig. 1b, the conical pair of breathing-tubes on the thorax being slowly protruded from two hardly perceptible warts, whilst the telescopic apparatus shrinks up, its functions being at an end. A variable time, dependent upon the season, elapses before the perfect insect makes its appearance, but prior to this occurring, a large circular plate, forming the thorax of the pupa, is thrust off, thus assisting the escape of the fly, which immediately ascends a plant, or other convenient object, to dry and expand its wings (Fig. 1). In the perfect state it delights to hover in the air, darting away with great rapidity on the approach of any enemies. It also frequently enters houses, where its presence is at once betrayed by a peculiarly shrill noise made while flying. The sexes of this insect differ chiefly in size, the female (Fig. 1) being about twice as large as her companion.

Closely allied to this species are Helophilus ineptus, and H. hochstetteri. The former is slightly smaller than H. trilineatus and may be at once distinguished by its tessellated orange-yellow and black abdomen. It is rather local, but extremely abundant wherever found. The latter has a superficial resemblance to some of the smaller blowflies (Musca), but may be readily known by its large brownish-red scutellum.[^[12]] It is the commonest of the genus and may be found in great numbers throughout the summer amongst veronica and other flowers.

Family Muscidæ.

Miltogramma mestor (?) (Plate [VII], fig. 5).

A conspicuous species, found occasionally on forest-clad hills round Wellington. The life-history is at present unknown, but its larva is very possibly parasitic in some large Lepidoptera.

Family Muscidæ.

Nemorea nyctemerianus (Plate [VII]., fig. 6).

This little fly is seldom met with in the perfect state. Its larva is parasitic on the caterpillar of Nyctemera annulata[^[13]], the eggs being deposited on the moth larva at an early age. The caterpillar grows and eats in the ordinary way, until it has assumed the chrysalis state, when the maggot eats its way out and changes into a dark-brown pupa. In this condition the parasite is protected by the web which was previously constructed by the unfortunate caterpillar for its own use. The perfect fly appears in about six weeks' time, its great agility and large white scales rendering it very conspicuous.

Family Muscidæ.

Eurigaster marginatus (Plate [VII]., fig. 7).

Another parasitic species, its larva inhabiting the caterpillars of various noctuæ which it destroys just before they change into the chrysalis state. The pupa of the parasite lies in a small oval cell constructed in the earth by its larva. A variable number of these maggots are found associated in one host, the smaller caterpillars only harbouring a single individual, while a large larva will frequently contain three or four. This species has been bred from the following Lepidoptera: Mamestra composita, M. ustistriga and M. mutans. It also occurs in the curious Œceticus omnivorus, being found in the cocoons of that moth in numbers varying from two to eleven, or even more, and it is especially interesting, as it is in turn destroyed by a small species of Pteromalus already noticed among the Hymenoptera (page [37]). The perfect insect occurs occasionally on flowers throughout the summer.

Family Muscidæ.

Calliphora quadrimaculata (Plate [VII]., fig. 9).

This is the large blue-bottle fly of New Zealand and is found everywhere in great abundance. Its larva feeds on decaying flesh and is of a dirty yellow colour, measuring, when full-grown, about seven lines in length. The pupa is buried at a considerable depth in the ground, the larva having descended before changing. The duration of this, and in fact of all the stages of the insect, depends entirely upon the temperature, but the females invariably deposit eggs, even during the hottest weather, and are never ovo-viviparous like the next species, and several others of the genus.

Family Muscidæ.

Sarcophaga læmica (Plate [VII]., fig. 10).

Another extremely abundant species having a similar history to the last, but its powers of development are very much accelerated owing to the larva being positively born alive. The females hover over meat and other suitable substances, depositing a number of minute wriggling maggots thereon, not infrequently to the great disgust of some hungry individual, who perhaps is making his dinner off a mutton chop which the fly has selected as a home for her offspring. These larvæ are all produced from distinct ova, which hatch before being laid, as I have often proved, by removing them from the insect's abdomen, and watching the young larva emerge from a minute elliptical white egg, covered with a thin leathery skin. Every one who has travelled in New Zealand must have noticed that, in the wildest spots, these insects assemble in large numbers as soon as any meat is uncovered, thus not only showing their universal distribution throughout the country, but also that they possess a very keen sense of smell.

Two British species at least, allied to this genus, have been introduced into New Zealand, viz., Musca domestica and Musca cæsar. The former is probably a world-wide insect, every ship teeming with it, but the latter is at present rather scarce and is usually found in the neighbourhood of farm-yards, where the larva feeds on cow-dung. The perfect insect may be at once known by its brilliant green colour.

Family Muscidæ.

Cylindria sigma (Plate [VII]., fig. 14).

A curious species, occurring occasionally in damp situations in the forest where it may be noticed leisurely walking over the leaves of various shrubs. It is very sluggish and may often be captured between the fingers without the aid of a net. Its life-history is at present unknown, but the larva probably feeds on fungi. The pretty little insect depicted at Fig. 11 may be found in similar situations but is not so common.

Family Muscidæ.

Phora omnivora, n.s. (Plate [VII]., fig. 15, 15a pupa).