Part 1

Transcriber's note: Text enclosed by underscores is in italics (_italics_). Text enclosed by underscores is in italics (_italics_). A carat character is used to denote superscription: a single character following the carat is superscripted (example: 27^9). The conventional male and female symbols are indicated by [M] and [F].

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NEW ZEALAND

MOTHS AND BUTTERFLIES.

"The rearing of larvæ, . . . when joined with the entomological collection, adds immense interest to Saturday afternoon rambles, and forms an admirable introduction to the study of physiology."

"When simple curiosity passes into the love of knowledge as such, and the gratification of the æsthetic sense of the beauty of completeness and accuracy seems more desirable than the easy indolence of ignorance; when the finding out of the causes of things becomes a source of joy, and he is counted happy who is successful in the search; common knowledge of Nature passes into what our forefathers called Natural History, from whence there is but a step to that which used to be termed Natural Philosophy, and now passes by the name of Physical Science."

"It is interesting to contemplate a tangled bank, clothed with many plants of many kinds, with birds singing on the bushes, with various insects flitting about, and with worms crawling through the damp earth, and to reflect that these elaborately constructed forms, so different from each other, and dependent upon each other in so complex a manner, have all been produced by laws acting around us. These laws, taken in the largest sense, being Growth with Reproduction; Inheritance which is almost implied by reproduction; Variability from the indirect and direct action of the conditions of life, and from use and disuse: a Ratio of Increase so high as to lead to a Struggle for Life, and as a consequence to Natural Selection, entailing Divergence of Character and the Extinction of less-improved forms. Thus, from the war of Nature, from famine and death, the most exalted object which we are capable of conceiving, namely, the production of the higher animals, directly follows. There is a grandeur in this view of life, with its several powers, having been originally breathed by the Creator into a few forms or into one; and that, whilst this planet has gone cycling on according to the fixed law of gravity, from so simple a beginning endless forms most beautiful and most wonderful have been, and are being evolved."

NEW ZEALAND

MOTHS AND BUTTERFLIES

(MACRO-LEPIDOPTERA).

BY

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

_Author of 'An Elementary Manual of New Zealand Entomology.'_

WITH 13 PLATES.

LONDON:

WEST, NEWMAN & Co., 54, HATTON GARDEN, E.C.

1898.

PREFACE.

The present work is intended as a guide to those who desire to collect or study our native _Lepidoptera_, and also as a book of reference to the general reader.

In the Introduction I have first given an outline of the Transformations and Structure of the _Lepidoptera_. Then a brief sketch of the Darwinian theories respecting the origin of species and their special application to various phenomena exhibited by moths and butterflies, as well as a short outline of the general principles which have been followed in framing modern classifications of the order. Next follow five chapters on the various groups dealt with.

With a few exceptions this work only treats of what are, for the sake of convenience, termed the _Macro-Lepidoptera_. A similar work on the numerous and interesting species of _Micro-Lepidoptera_ found in New Zealand may at some future time be undertaken.

In conclusion, I have to discharge the pleasurable duty of thanking the numerous entomologists who have so liberally assisted me in the production of this work. First, and especially, my thanks are due to Mr. Meyrick, without whose masterly papers and 'Handbook' but little could have been accomplished. Next, to Mr. R. W. Fereday, who very kindly allowed me to figure many species of which he alone possesses specimens--in itself an invaluable assistance. I have also to express my thanks to Messrs. E. F. Hawthorne, H. P. Hanify, R. I. Kingsley, A. Norris, A. Philpott, and others for the loan of specimens, and for much valuable information regarding the localities and habits of rare or local species. Lastly, I have to acknowledge the aid so willingly given by my lamented friend, the late Mr. A. S. Olliff, of Sydney.

KARORI, WELLINGTON, NEW ZEALAND, 1897.

CONTENTS.

PAGE

INTRODUCTION ix

THE CARADRININA 1

THE NOTODONTINA 38

THE PAPILIONINA 101

THE PSYCHINA 122

THE MICROPTERYGINA (PART ONLY) 127

APPENDIX (DESCRIPTIVE LIST OF PLANTS) 137

GENERAL INDEX 141

SPECIAL INDEX 142

PLATES AND EXPLANATIONS 145

{ix}INTRODUCTION.

The order _Lepidoptera_, which includes all those insects commonly known as Moths and Butterflies, is chiefly distinguished by its members possessing four wings clothed with numerous minute scales, the term _Lepidoptera_ being derived from the two Greek words, [Greek: lepis], a scale, and [Greek: pteron], a wing. The mouth of these insects is suctorial, the maxillæ forming a spiral proboscis which is coiled up between the large labial palpi when not in use (see Plate I., figs. 5 and 6). The other oral organs are rudimentary. To acquire this form these insects pass through three very distinct stages, viz., the Egg, the Larva, and the Pupa.

I.--METAMORPHOSIS.

THE EGG.

The eggs of _Lepidoptera_ are generally somewhat globular, much flattened above and beneath. Some are very elaborately sculptured, whilst others are quite smooth. They are usually white or yellowish, but always change much in colour as the contained embryo develops.

THE LARVA.

The larvæ of moths and butterflies are popularly known as caterpillars. They always consist of thirteen segments, segment number one being the head. The head is furnished with several simple eyes (Plate I., fig. 2, AA), a pair of very short antennæ (BB), and a very powerful masticatory mouth. The mouth consists of the following organs: The labrum, or upper lip (1); a pair of mandibles, or upper jaws, working like scissor-blades (2,2); two maxillæ, or lower jaws (3,3), each carrying a jointed organ termed the maxillary palpus; and the labium, or lower lip (4); which bears another pair of minute jointed appendages--the labial palpi.

Segments 2, 3, and 4, which answer to the thorax of the perfect insect, are each furnished with a pair of legs. They consist of the six following joints (fig. 2): (_a_) coxa, (_b_) trochanter, (_c_) femur, (_d_) tibia, (_e_) tarsus, and (_f_) claw. These legs correspond to those of the perfect insect. The remaining nine segments of the body constitute the abdomen. Usually segments 7 to 9 and 13, each have a pair of fleshy pads, which are termed prolegs and are furnished on their edges with a row of minute hooklets (see Plate I., fig. 14, proleg highly magnified). It is these hooklets which enable caterpillars to hold on by means of their prolegs with such great tenacity. The number of the prolegs varies considerably in different groups and families.

The _spiracles_, or orifices of the air-tubes, are situated on each side of the larva just above the legs. They are usually present on segments 2 and 5 to 12, but vary {x}considerably in different groups and families. The larva is provided with a very complete digestive system, which consists of the following organs (see Plate I., fig. 9): A, the oesophagus; D, the ventriculus; F, the clavate intestine; E, the ilium; H, the colon; K, the biliary vessels; and O, the spinning vessels. These last open at a small orifice in the labium termed the spinneret (fig. 2, 5). They supply the silken threads which are employed by most larvæ in constructing their cocoons, and which also serve in cases of danger as a rapid means of retreat. Many larvæ, which live on shrubs and trees, suddenly lower themselves to the ground by means of one of these silken threads, and thus often escape being devoured by insectivorous animals.

The entire growth of the insect is accomplished during the larval condition, the increase in size being frequently very rapid. Owing to this circumstance larvæ are often compelled to shed their skin, and in many species a very considerable alteration both in the shape and colour takes place at each moult, or ecdysis as it is sometimes termed.

THE PUPA.

The pupa of a Lepidopterous insect is completely encased in a chitinous envelope. With the exception of a slight twirling of the abdominal segments it is incapable of any motion. In the pupa of _Micropteryx_ the mandibles and labial palpi are said to be functionally active, but this is a very exceptional though extremely interesting case. In conjunction with other evidence it would appear to indicate that the _Lepidoptera_ originated from insects with active pupæ. The number of free or movable segments of pupæ varies considerably in different groups and genera, and by some modern authors it is regarded as a character of much importance in the framing of their classifications. The various organs of the perfect insect are distinctly marked out on the otherwise uniform integument of the pupa. In some groups, notably the _Micropterygina_, these organs are much more distinctly indicated than in others.

II.--ANATOMY.

THE PERFECT INSECT OR IMAGO.

In common with all other members of the class, the body of a Lepidopterous insect consists of three main divisions: (1) the head, (2) the thorax, and (3) the abdomen.

THE HEAD.

The front of the head is termed the _face_, the top the _crown_, the sides are nearly entirely occupied by the compound eyes (Plate I., fig. 11, AA), and the lower surface by the organs of the mouth.

The _Eyes_ consist of a very large number of simple lenses arranged in the form of two hemispheres, one on each side of the head. The _ocelli_, or simple eyes, are situated on the crown, and are usually almost entirely covered by scales.

The _Antennæ_ are two jointed appendages attached to the top of the head above the eyes. They vary very much in structure. The following are the terms used in describing the different forms of antennæ in the _Lepidoptera_:--

1. _Pectinated_, when the joints have long processes like the teeth of a comb. If these are on one side only, the antennæ are _unipectinated_; if on both sides, _bipectinated_. (Plate I., fig. 20, bipectinated antenna of _Nyctemera annulata_.)

2. _Dentate_, when the joints are armed with slight pointed spines.

{xi}3. _Serrate_, when the joints have sharp projections like the teeth of a saw. (Fig. 18, antenna of _Melanchra composita_.)

4. _Filiform_, when the whole antenna is simple or thread-like. (Fig. 19, antenna of _Epirranthis alectoraria_.)

The clothing of the antennæ also varies, and is distinguished as under:--

1. _Ciliated_, when clothed with one or two series of short, fine hairs.

2. _Fasciculate-ciliated_, when the hairs are collected into tufts. (Fig. 17, antenna of _Chloroclystis plinthina_.)

3. _Pubescent_, when the antennæ are clothed with uniform short hairs. (Fig. 19.)

The functions of the antennæ are still a matter of dispute amongst entomologists. The majority of the older naturalists regarded them as organs of hearing. The antennæ are almost always more fully developed in the male than in the female. From this circumstance many modern entomologists consider that one of their functions is to enable the former to find the latter.

The organs of the mouth are thus distinguished:--

1. The _Labrum_, or upper lip (Plate I., fig. 11, _l_), a minute rudimentary plate situated in front immediately above the proboscis.

2. The _Mandibles_, or upper jaws (m.m), two minute sickle-shaped organs situated just below the labrum, also rudimentary.

3. The _Proboscis_, or _Haustellum_[1] (c), a tubular extensible organ formed of the two maxillæ, or lower jaws, which have become greatly elongated, semi-tubular, and closely pressed together at the edges, but separable at the will of the insect--a structure which enables the organ to be easily cleansed when necessary, and is extremely interesting as indicating so clearly the true development of the proboscis from the maxillæ.

The _Maxillary palpi_ (p.p) are two jointed organs attached to the base of the proboscis and very frequently rudimentary, but fully developed amongst certain of the _Micro-Lepidoptera_.

The _Labium_, or lower lip, is situated below the proboscis and carries the _Labial palpi_ (figs. 5 and 6), two large jointed organs which are very conspicuous in nearly all the species and often quite conceal the maxillary palpi. They are usually regarded as organs of touch, but their true function does not seem to be properly understood. In the _Lepidoptera_ they appear to protect the proboscis, which, when out of use, is always coiled up in a spiral between them. The labrum and mandibles can only be seen by removing the large labial palpi.

THE THORAX

carries the organs of locomotion, which consist of two pairs of wings attached to its sides, and three pairs of legs attached beneath, a pair belonging to each of the three segments of which the thorax is composed. On the front of the thorax there are two flap-like organs covered with scales, termed the _patagia_.

The _Wings_ vary greatly in shape, but usually they are triangular. The portion of the wing which joins on to the thorax is termed the _base_. The front margin is called the _costa_, the outer margin the _termen_, and the lower margin the _dorsum_, these being described as situated when the wing is extended in flight. The angle between the costa and termen {xii}is called the _apex_, and the angle between the termen and the dorsum the _tornus_ (see Plate I., fig. 1). The termen and dorsum are edged with a fringe of hair-like scales, termed the _cilia_. At the base of the hind-wings is generally situated a stiff bristle, or several stiff hairs, called the _frenulum_, the ends of which pass through a chitinous process on the under side of the fore-wing near the dorsum. This process is termed the _retinaculum_, and serves, in conjunction with the frenulum, to lock the wings together during flight. In the female both these organs are often very imperfectly developed, the frenulum consisting of several bristly hairs, and the retinaculum of a group of stiff scales. In many of the _Lepidoptera_ both frenulum and retinaculum are entirely wanting.

"In the _Micropterygina_, a membranous or spine-like process called the _jugum_ rises from the dorsum of the fore-wing near the base and passes under the hind-wing, which is thus held between the process and the overlapping portion of the fore-wing."--(Meyrick.)

The veins of the wings are thus described by Mr. Meyrick:--

"The wings are traversed by a system of _Veins_--tubular structures which serve at once as extensions of the tracheal system, and to form a stiff framework for the support of the wing. In the normal type of _Lepidoptera_ the fore-wings possess three free veins towards the dorsum, termed 1_a_, 1_b_, and 1_c_; a central cell, out of which rise ten veins, numbered 2 to 11, the sides of the cell being known as the upper median, lower median, and transverse veins respectively; and a free subcostal vein, numbered 12; whilst the hind-wings differ from the fore-wings in having only six veins rising from the central cell, numbered 2 to 7, so that the free subcostal vein is numbered 8 (see Plate I., figs. 3 and 4, assumed type of neuration of a Lepidopterous insect). In some forms a forked parting-vein traverses the middle of the cell longitudinally, and a second parting-vein traverses the upper portion, so as to form a secondary cell; but these are more frequently absent or represented only by folds in the membrane. In a few forms there is a tendency to the production of several false veins, termed _pseudoneuria_, appearing as short branches from the subcostal vein of the hind-wings to the costa; these are thickenings of the membrane, and are commonly very irregular and variable, often uneven in thickness or incomplete. Sometimes one of these near the base is better developed and more permanent in character; it is then termed the _præcostal spur_ (see Plate I., figs. 8^9 and 27^9). Modifications in the general arrangement of the veins may arise through any of the following processes, viz.: (1) _obsolescence_, when a vein loses its normal tubular structure, becoming attenuated and reduced in substance, until it appears a mere fold of the membrane (Plate II., fig. 60, vein 5 in hind-wings of _Selidosema_); (2) _stalking_, when the two veins are fused together for a portion of their length from their base, so as to appear to rise on a common stalk (Plate II., fig. 34, veins 6 and 7 in hind-wing of _Hydriomena_); (3) _coincidence_, when two veins are fused together for the whole of their length, so that one appears entirely absent, an extreme form of stalking; (4) _anastomosis_, when two veins rise separate, meet, and are fused together for a certain distance, and then separate again (Plate II., fig. 23, veins 7 and 8 in the hind-wings of the [F] of _Tatosoma_); (5) _concurrence_, when a vein rises separate, runs into another, and does not separate again, an extreme form of anastomosis; (6) _connection_, when two veins are connected by a short transverse bar passing from one to the other, a special form of anastomosis, evolved from the ordinary form under the influence of a tendency to lateral extension (Plate II., fig. 28, veins 7 and 8 in hind-wing of _Paradetis_). Vein 1_b_ in both wings is often furcate at the base.

{xiii}"The type of veins in the _Micropterygina_ differs from that described above in two essential particulars, viz.: (1) there may be three additional veins in the fore-wings, rising out of vein 11 or 12; and (2) the veins of the hind-wings are practically identical in number and structure with those of the fore-wings, being thus much more numerous than in the ordinary type. There is also often a system of cross-bars between the veins near the base of the wing (Plate I., figs. 22 and 23, neuration of _Hepialus_).

"The structure of the veins can be best observed on the under surface of the wing, where they are more prominent. The student should begin by completely denuding of scales a few wings of common species: the wing should be cut off and laid on a moistened piece of glass, to which it will adhere; the scales should then be removed, first from one surface and then from the other, with a fine, moist camel's-hair brush--an operation requiring a little patience and delicacy of touch; the veins will thus be rendered conspicuous.[2] When, however, the student has familiarised himself with the general subject, it will not be found necessary in practice to resort to this process; most details will be easily observed without denudation[3]; where this is not the case (as where the veins are closely crowded or otherwise obscured), the scales can be removed with the brush on the under surface in the locality of the difficulty only, without cutting off the wing or otherwise damaging the specimen, which remains in the collection available for all purposes as before; with proper practice, even the smallest species are amenable to this treatment, which does not require more skill than the actual setting of the specimen. Some workers prefer to put a drop of benzine on the spot, which renders it temporarily transparent; the effect is short-lived, as the benzine evaporates rapidly, and the cilia (if long) are liable to be damaged by this method."

The _Legs_ consist of the following joints (see Plate I., fig. 21): (1) _coxa_, (2) _trochanter_, (3) _femur_, (4) _tibia_, (5) _tarsus_, (6) _claw_. The tarsus normally consists of five joints, but is more or less aborted when the leg is not employed for walking. The spines (SS) on the tibiæ of the several legs vary considerably in size and number. They are often useful to the systematist for purposes of classification.

THE ABDOMEN

consists of nine segments, some of which are often fused together. It contains the various internal organs, of which the most important are those of Digestion and Reproduction. The _Digestive System_ (Plate I., fig. 10) consists of the following organs: A, the _oesophagus_, or throat; C, the _sucking stomach_; D, the _ventriculus_ or stomach; E, the _small intestine_; G, the _cæcum_; H, the _colon_; K, the _biliary vessels_; N, the _salivary vessels_. The function of the _sucking stomach_ is to exhaust the air in the throat and proboscis, and thus to cause the ascent of the fluids into the stomach when the insect is feeding.

III.--ORIGIN OF SPECIES.

The theory of the origin of species as propounded by Darwin may be thus very briefly summarised:--

{xiv}VARIATION.--No two organisms are exactly alike; there is always some variation from the parent form, in some cases very slight, in others considerable. (For examples of variation see Plate VII., figs. 1 to 9, varieties of _Hydriomena deltoidata_; Plate VIII., figs. 42 to 47, varieties of _Epirranthis alectoraria_; Plate IX., figs. 6 to 14, varieties of _Selidosema productata_; Plate X., figs. 13 to 23, varieties of _Azelina gallaria_; Plate X., figs. 39 to 47, varieties of _Declana floccosa_.)

INHERITANCE.--Many of these variations are inherited--a fact demonstrated by our domestic plants and animals, where man has selected and bred from varieties suitable for his purposes, and has thus produced races in which the variation is permanent. Many of the races of domestic animals differ as much from one another as do some distinct species of wild animals.

STRUGGLE FOR EXISTENCE.--All animals and plants produce far more offspring than can possibly survive, thus giving rise to the struggle for existence. For example: The average number of eggs laid by a Lepidopterous insect is certainly over 100, and in many species this number is greatly exceeded. Assuming each female to lay 100 eggs, the progeny from a single pair would amount, after six generations, to over six million individuals.

NATURAL SELECTION, or the SURVIVAL OF THE FITTEST.--In the struggle for existence which necessarily results from such a great increase of individuals, those variations which favoured the possessors would be preserved, whilst those which did not, would be gradually exterminated. This principle of the preservation of the favourable varieties in the struggle for life is called Natural Selection, or the Survival of the Fittest.