CHAPTER V
CLASSIFICATION OF THE LEPIDOPTERA
The
Lepidoptera
are divided into two very unequal groups, to which we have so frequently alluded as 'Butterflies' and 'Moths.' And, although these two terms are popularly applied in a fairly accurate manner, yet, strange to say, very few persons indeed have any definite knowledge of the differences that entomologists recognise between the two groups.
Every entomologist has his circle of sympathetic and, perhaps, even admiring friends. Consequently, many a little package is sent round to his abode 'with great care,' accompanied by a note or a message concerning the fine 'butterfly I have just caught, and thought you would like to add to your collection.'
The 'butterflies' that so frequently reach us through these channels nearly always turn out to be
brightly coloured
moths, and this naturally gives one the idea that the popular notion as to the classification of the
Lepidoptera
is based on colour or brilliancy of design, the term 'butterfly' being applied to the gayer species, and 'moth' to the more dingy members of the race.
There is really some shadow of a reason in this method of nomenclature, for butterflies
are usually
more brightly clad than moths; but the scientific classification, at least as far as the main divisions and subdivisions are concerned, has nothing whatever to do with colour or design; and we must at once acquaint ourselves with the fact that there
are
very dingy butterflies, and most beautiful and highly coloured moths.
How shall we account for the fact that the specimens so kindly sent us by our friends are generally moths? Is it because moths are more numerous and more frequently seen? They are certainly more numerous; for, while our butterflies do not number seventy species, the other division contains about two thousand. Yet, in spite of this fact, moths are not generally observed as much as butterflies, for the former are nearly all night-fliers, and the latter
always
fly by day and rest by night.
Still our question remains unanswered. The reason is this. The captives sent us are seldom caught on the wing. Most of our grown-up friends, even though they admire our own pluck and general carelessness concerning the remarks of the spectators of our entomological antics, would not themselves like to be seen, hat in hand, chasing a butterfly; and the night-flying moths are, of course, less frequently observed. But they often, in the course of their daily employments, meet with a large moth fast asleep in some corner of a dwelling house, workshop, or outhouse. Such moths are easily caught while in the midst of their slumbers, and, as they often make no attempt to fly by day, are as easily transferred to a box suitable for transmission by messenger or by post.
In the above few remarks we have alluded to some features by which the two great groups of the
Lepidoptera
may be distinguished; but we have already referred (
page 5
) to a far more important one in our description of the various forms of antennæ. All butterflies – at least all
British
butterflies – have knobbed or clubbed antennæ, while the corresponding organs of all our moths terminate in a sharp point.
This distinction obtains in all British
Lepidoptera
, and is so far regarded as the most important basis of classification that naturalists have derived from it the two Greek terms that are synonymous with our two popular names – butterflies and moths. The scientific name for the former group is
Rhopalocera
– a term derived from two Greek words, one signifying a horn, and the other a club, and thus meaning 'club-horned.' The corresponding name for moths is
Heterocera
, derived from the same source, and meaning 'variously horned.'
But, although we find embodied in these two long and formidable names an unerring mark of distinction between British butterflies and moths, we must not neglect other less important facts which, though less distinctive, are not without interest.
Observe a butterfly at rest. Its wings are turned vertically over its back, and brought so closely together that they often touch. In this position the 'upper' surfaces of the 'upper' wings are completely hidden from view, and the 'under' surfaces are exposed on the two sides, except that those of the 'upper' pair are partly hidden by the other pair.
Now look at a moth under the same circumstances, and you will generally find the wings lying over its body, which is almost or completely hidden beneath them. As a rule the upper pair together form a triangular figure, and entirely cover the second pair; but in some cases a portion of each of the under wings extends beyond the margin of those above them, and in others the upper pair extend so far forward that nearly the whole of the under wings is exposed behind them.
Fig. 37. – A Butterfly at Rest (Large Copper).
Fig. 38. – A Moth at Rest (Gothic).
Again, the wings of butterflies are so rigid that they can never be folded; but you will observe that the under wings of moths are generally very thin, soft, and pliant, and are neatly pleated lengthwise when not in use.
Another feature deserving notice is a slight difference to be often observed in the form of the body. The butterfly, which generally has a slender body, has a distinct constriction or waist between the thorax and abdomen. This is not so apparent with moths, and especially with the thick-bodied species.
The
Rhopalocera
or Butterflies are divided into
Families
, each of which contains insects that possess certain features in common by which they may all be distinguished from the members of any other family.
The British species represent eight families. They are as follows:
1.
Papilionidæ.
– Containing only one British species – the beautiful Swallow-tail (
Plate I
, fig. 1).
2.
Pieridæ.
– Containing ten species. These are often known collectively as the 'Whites,' but include four butterflies that are distinguished by beautiful shades of yellow and orange.
3.
Nymphalidæ.
– This family contains seventeen insects, among them being several splendid species. It includes the Fritillaries and Vanessas.
4.
Apaturidæ.
– Of this we have only one representative – the Purple Emperor (
Plate V
, fig. 1).
5.
Satyridæ.
– Including the 'Browns' and 'Heaths,' and numbering eleven species.
6.
Lycænidæ.
– Including the Hairstreaks, 'Coppers,' and 'Blues,' in all seventeen species.
7.
Erycinidæ.
– Containing only the 'Duke of Burgundy.'
8.
Hesperiidæ.
– This family contains seven British butterflies commonly known as the 'Skippers.'
Although all the members of the same family resemble each other in certain points of structure, or in their habits, yet we can often find among them a smaller group differing from all the others in one or two minor particulars. Such smaller groups are called
Genera
.
To make this all quite clear we will take an example.
The Brimstone Butterfly (
Plate II
, fig. 4) belongs to the second family —
Pieridæ
,
all
the members of which are distinguished from those of the other families by the characteristics mentioned on
page 141
.
But our Brimstone Butterfly possesses another very prominent feature in which it differs from all the other British
Pieridæ
, and that is the conspicuous projecting angles of both fore and hind wings. Among the foreign species of the family we are considering there are several that possess these angles; but as there are no others among our own members, the 'Brimstone' is placed by itself in the list of British
Lepidoptera
as the only member of the genus
Gonopteryx
or 'angle-winged' butterflies.
Thus the full relationship of this butterfly to other insects may be shown in the following manner:
The Brimstone Butterfly.
ORDER.
—
Lepidoptera
Section.
—
Rhopalocera
Family. —
Pieridæ
Genus.
—
Gonopteryx
Species. —
Rhamni
Now, every butterfly has a Latin or Greek name in addition to that by which it is popularly known. I should have said
two
Latin or Greek names. The first of these is always the
generic
name, and the second is the one by which we denote the particular member or
species
of that genus. Thus, the scientific name of the Brimstone Butterfly is
Gonopteryx Rhamni
.
'But,' the reader may be inclined to ask, 'why should we not be satisfied with the one popular name only?' And, 'If we
must
have a separate scientific name, could we not find suitable terms among our English words to build up such a name – one that might express the principal characteristics of the insect, and also serve all the purposes of classification?'
Such questions sound very reasonable, and so they are. But the entomologist's answer is this. We ourselves may get on well without the help of the dead languages, but we have brother naturalists all over the world, speaking a great variety of different languages. We endeavour to help one another – to exchange notes and generally to assist one another in our labours; and this can be greatly facilitated if we all adopt the same system of nomenclature. The educated of most of the great nations generally know something of Latin and Greek, and consequently the adoption of these languages is generally acceptable to all.
This sounds well, but for my own part I believe that if we are to make any branch of natural history a popular study, especially with the young, we must to a certain extent avoid anything that may prove distasteful. There is no doubt whatever that many a youngster has been turned away from the pursuit of the study of nature by the formidable array of almost unpronounceable names that stretch nearly halfway across a page; and those who desire to make such a study pleasant to beginners should be very cautious with the use of these necessary evils. One would think, on glancing over some of the scientific manuals that are written 'especially for the young,' that the authors considered our own too mean a language for so exalted a purpose, for in such works we find all or nearly all the popular names by which the schoolboy knows certain creatures he has seen entirely omitted, and the description of a species appended to a long Latin term that conveys no idea whatever to the reader, who is studying the description of a well-known animal or plant and doesn't know it.
Our plan will be to give the popular names throughout, except in the case of those few species that are not so well known as to have received one; but the scientific names will always be given as well for the benefit of those readers who would like to know them. And the short description of the method of classification just given will enable the more ambitious of my readers to thoroughly understand the table of British butterflies and moths toward the end of the book.
This table includes
all
the British species of butterflies and of the larger moths; and the arrangement is such as to show clearly the divisions into sections, families, &c. It will therefore be of great value for reference, and as a guide for the arrangement of the specimens in the cabinet.
In the foregoing description of the method of classification butterflies only are mentioned; but the division and arrangement of moths is carried out in just the same manner except that the system is a little more complicated. The number of moths is so large in comparison, that we are able to select from them some very large groups the species of which possess features in common. These groups are termed
tribes
, and are again divided into families just like the butterflies. Thus the arrangement of moths includes
tribes
,
families
,
genera
and
species
. We will take an example by way of illustration as we did before, and ask the reader to verify the same by comparison with our table:
Example.
– The 'Common Tiger' (
Plate X
, fig. 3).
ORDER.
—
Lepidoptera
Section.
—
Heterocera
TRIBE. —
Bombyces
Family. —
Cheloniidæ
Genus.
—
Arctia
Species. —
Caia
Scientific Name. —
Arctia Caia.
I have already said that the Latin and Greek names of butterflies and moths are not at all necessary to the young entomologist. It is quite possible to be well acquainted with the natural history of these creatures, and to derive all the pleasure and benefits that the study of them can afford without the knowledge of such names; but most entomologists go in for them, often to the entire exclusion of the popular English terms.
There are those who consider themselves (or would have us consider them) expert entomologists because they have the power to vomit forth a long list of scientific names of butterflies and moths which (to them) have no meaning whatever; and it is astonishing that we meet with so many youngsters who can rattle away such terms, and, at the same time, are totally ignorant of the real nature of the creatures they name.
If you wish to be a naturalist in the true sense of the term, study your
specimens
, and take but little pains to commit their hard names to memory; and you will then find that the latter will gradually become your own property without any special effort on your part. Your continued reference to illustrated works and museum collections will bring them to you almost unconsciously, and you will generally find your entomological vocabulary extending as rapidly as your cabinet becomes filled.
Again, with regard to the
meanings
of the scientific terms, don't trouble much about them. It unfortunately happens that in a very large number of cases these names are ill chosen, and do not in any way refer to the distinguishing characteristics of the species to which they are applied. You will observe, too, if you look at the table, that many insects have
two
scientific names applied to the species, one being placed in brackets after the other. In such cases both these names are in common use, having both been applied by independent authorities, and the insertion of the two will prove an assistance at times.
It is a common practice with entomologists, in their communications, to use only the second or
specific
name of insects. Thus, they would speak of the Brimstone Butterfly as
Rhamni
, and not
Gonopteryx Rhamni
. When
writing
a communication, however, they very commonly place in front of the specific name the initial letter of the first or
generic
name. Thus the full title of the butterfly just mentioned would be abbreviated to
G. Rhamni
.
Having said so much concerning the principles of classification and nomenclature, we will pass on to the practical portion of the entomologist's work.
PART II
WORK AT HOME AND IN THE FIELD
CHAPTER VI
CATCHING BUTTERFLIES AND MOTHS
It is not at all surprising that entomology should prove such a fascinating study to the young, and more especially that portion which deals with the department we are now considering. Butterflies and moths are among the most beautiful and most interesting of living creatures. The study of their life history is enchanting, and the creatures themselves are of such a size as to be conveniently handled and preserved, and withal occupy so little space that anyone with only moderate accommodation may possess a fairly typical collection.
Compare the work of the entomologist with that of one whose hobby is the study of mammals. The latter has to deal with large and cumbersome objects, a collection of which requires an enormous amount of space; and, unless he has the time and means to travel in foreign countries, he cannot get together a good typical collection of specimens representing his particular branch, for the few British mammals contain no representatives of several of the orders into which the class is divided.
Entomology is undoubtedly,
par excellence
,
the
study for youngsters. It is equally suited to the studious and to those of an adventurous turn of mind. It leads its follower into the bright sunshine and the flowery meadows; and with body and mind pleasantly occupied, the joy of living is deeply felt. The necessary apparatus can be made by anyone. No dangerous gun is required, and there are no precipitous rocks to scale. When the autumn flowers fade the year's work of the entomologist is not done, for the arranging of his cabinet and the demands of his living specimens keep him more or less actively engaged until the flowers of the following spring call both him and the insects he loves once more into the field. And so, season after season, and year after year, he finds himself engrossed in labours so fascinating that idleness – the curse of so many of our youths – is with him an impossibility.
I assume that the readers of this book have a desire to take up the study of one branch of entomology – that of butterflies and moths – in real earnest; that they intend not only to
read
about these interesting insects, but to
know
them. And there is only one way in which one may really get to know living creatures; that is by searching them out in their haunts, observing their growth and habits, and by an occasional close examination in order to become acquainted with their structure.
Hence I shall in this, the practical portion of the work, give such information as will assist the beginner in catching, preserving, rearing, breeding, and arranging the specimens that are to form his collection.
Catching Butterflies
There was a time when we would try to capture a butterfly at rest on a flower by a quick sweep of the hand, or, more commonly, by a sharp downward stroke of the cap. We were led to this action by a mere childish love of sport, or by a desire to possess an insect simply because it was pretty. When we succeeded in securing our prize, we handled it somewhat carelessly, often passing it from one hand to the other, or boxing it in our closed and perspiring fist till our fingers were dusted with the pretty microscopic scales of the creature's wings, and the wings themselves, stripped of all their beautiful clothing, were merely transparent and veined membranes. Having thus carelessly but unintentionally deprived the creature of its greatest beauty, we set it free, often in such a damaged or exhausted condition that the poor thing could scarcely fly.
But our childish ideas and inclinations have vanished. Now we would rather watch the insect than catch it, for we find much pleasure and interest in its varied movements. And if for purposes of study we occasionally require to make one captive, we proceed in such a manner as to preserve its beauty unimpaired. The cap now gives place to a well-made and suitable net; and we are careful to provide ourselves with sufficient and proper accommodation for our captives.
It is probable that many of my readers are as yet unacquainted with the nature of an entomologist's requirements for field work, so we shall describe them, confining ourselves at first to those that are required for a butterfly hunt.
First and foremost comes the net. This essential portion of your equipment may be either purchased or constructed by yourself. Very little skill is required to enable you to do the former. Provided your pocket is well charged, you may start off at once to the dealer in naturalists' appliances, and treat yourself to a complete outfit. But even in this case a little advice may not be out of place. See that what you purchase is very
strongly
made. You can get nicely finished nets constructed on the most convenient principles, made to fold and go in an ordinary coat pocket, but with
weak joints
. See that you have the most convenient form of net by all means, but do not go in for convenience and appearance at the expense of strength and durability. Nothing is more annoying than to find your net give way just when you are in the midst of a good day's sport.
Fig. 39. – A Wire Frame for a Butterfly Net.
Fig. 40.
The folding net is certainly very convenient, for you can conceal it in your pocket while you are walking through town or travelling in a railway carriage, and thus avoid that contemptuous gaze which certain of the public are prone to cast on a poor 'bug hunter.' And although such nets are generally purchased, yet they
may
be constructed by anyone who has had experience in the working of metals. But other forms of nets, equally useful and even stronger, can be made by anybody; and I will give a few hints on two or three different ways of putting them together.
A very simple and strong frame for a net may be made as follows: Get a piece of stout iron or brass wire about forty inches in length, and bend it into a circle with the two ends, turned out about two inches each, at right angles to the circumference as shown in the accompanying sketch.
Now take a good tough stick, the length of an ordinary walking stick, and cut out two grooves opposite each other at the end, just large enough to take the straight ends of the wire. The end of the stick will now resemble fig. 40 in shape. Place the ends in their grooves, and bind them tightly to the stick by a good many turns of rather fine wire.
A frame well made after this fashion is as strong as anything you could desire, but it has the disadvantage of being always fixed to the handle, thus preventing the use of the latter as a walking stick when you are not directly engaged in your entomological work.
A much more convenient frame may be made by thrusting the ends of a piece of cane into the two narrow arms of a metal
Y
. You may purchase the
Y
at any of the naturalists' stores, or you can make one yourself if you know how to perform the operation of soldering. I have always made mine with odds and ends of brass tubing such as old gas pipes. One piece must be just the size to fix on the stick; and the other two must fit the cane tightly. The three pieces must be filed off at the proper angles, and the doubly bevelled end of the wider tube must then be flattened down to the width of the smaller ones before soldering. If you decide to buy one, give the preference to strong brass rather than the cheaper and more fragile ones made of tinned iron.
Fig. 41. The Metal Y.
The advantage of such an arrangement over the last frame is evident at once. The cane, with net attached, can be pulled out of the
Y
when not in use, and bent small enough to go in the pocket or a satchel; and the
Y
can also be separated from the stick, thus allowing the latter to be used as a walking stick.
Some entomologists speak very favourably of what is known as the 'umbrella net' – a large and light net that will shut up like an umbrella, and may even be made to look very much like this useful protector, but the possession of such an imitation is somewhat tantalising in a pelting shower. The ring of this net consists of two steel springs attached to a couple of brass hinges, one of which is fixed near one end of the handle, while the other slides up and down in the gamp fashion.
One other form of net – 'the clap net' – although still occasionally seen, has had its best days. Two sticks are provided to this one, so that the two sides of the net may be brought together on the insect; but as both hands are required to manage it, it is almost surprising that it ever had any advocates at all.
When your frame is completed, sew round it a strip of strong calico, to which the net itself may be afterwards sewn, for the lighter material of the net is too delicate to stand the constant friction against the metal or cane frame.
The material usually employed in making the 'bag' is called leno. It can be purchased at most of the drapers' shops, and three colours – white, yellow and green – are usually kept in stock. Measure the circumference of your net frame, and see that you get sufficient leno to make a good full net. Suppose, for instance, that the circle of your frame measures thirty-six inches round, then your leno should be at least forty inches in length. Fold this double, and then cut out two pieces of the shape shown in fig. 42, letting the depth of the net be nearly or quite equal to the width of the material. There is nothing to be done now but to stitch the bag together and sew it to the calico on the ring.
Fig. 42.
At first you will find the leno rather stiff and harsh, but a damping and good rubbing between the hands will soften it down; or, if you prefer it, you may soften the material by a slight washing before cutting out the net. The latter is perhaps the better plan, for the washing will remove the objectionable 'dressing' that renders the material rather hard and stiff.
Of the three colours mentioned above, green is the one most generally chosen, because it is more in harmony with the surroundings of a butterfly catcher; but many prefer the white leno to the green, as the insects are more easily seen in a net of this colour. Yellow is certainly not a desirable tint.
As a rule it will be necessary to kill an insect as soon as it is captured. This is always the case with butterflies unless you require to keep them alive either to watch their movements or to obtain eggs. For this purpose you will require a killing bottle or box containing some volatile substance.
The selection of this necessary piece of apparatus is a point deserving of much consideration, for so many different forms are in use by different entomologists, and so many advocates each declare that his own plan is far superior to that of any of the others, that the final decision is not to be worked out in a moment. The best thing for a beginner is to try as many as he can, and then, after some considerable experience of his own, he will be able to decide which apparatus suits himself best.
I recommend this because it is impossible to say of any one plan that it is the best, for that which gives perfect satisfaction to one individual will often fail to give anything but annoyance in the hands of another.
To enable my young readers to follow the advice I have just given, I will describe some of the commonly used killing arrangements and show how they should be used.
I will take first the 'cyanide bottle.' This is a wide-mouthed bottle, containing a very poisonous substance called
cyanide of potassium
. It is fitted with a good sound cork. The 'cyanide' is a solid substance, and must be fixed in some way or other at the bottom of the bottle so that it cannot shake about and damage the butterflies.
Fig. 43. – The Cyanide Bottle.
A cyanide bottle can be purchased ready for use at the cost of a shilling or thereabouts; but if you are old enough to be trusted with deadly poisons, you may buy the 'cyanide' of a chemist who knows you well and is satisfied as to your intentions, and then prepare your own. Every entomologist should know how to do this, for the poison loses its power after some time, and it is not always convenient to leave your bottle in the hands of a chemist or a 'naturalist' to have it recharged. This will cost you more than it would to do it yourself, but that is nothing compared with the annoyance that may result when, the night before an anticipated butterfly hunt, you are calmly told that 'your bottle will be ready in a few days.' You can charge it yourself in a few minutes if you can manage to keep a small supply of 'cyanide' in stock, and it is ready for use very shortly after.
Here is the
modus operandi
. – Purchase an ounce or two of the cyanide of potassium, and immediately put it into a stoppered or well-corked bottle. Label it at once, not only with the name, but also with the word Poison in very large and conspicuous letters. This dangerous chemical is often sold in sticks that look much like certain 'sugar sticks' I was acquainted with in my younger days; but whether this is or is not the case with your cyanide, see that the bottle is kept quite out of the reach of the inquisitive and sugar-loving juveniles of the house.
The quantity above mentioned is more than you will require for the first 'charge,' but you will soon experience the convenience of having a supply always at hand for recharging when your cyanide bottle fails to do its work expeditiously, or when an accident calls for the somewhat sudden appearance of a new one.
Now procure a bottle for your work. Its mouth must be wide enough to take the largest insect you hope to catch, and the widest part of the bottle need not be much larger. Get a perfectly sound cork to fit it tightly; and, to insure the more perfect exclusion of air, paint over the top of the cork with melted paraffin wax.
Dissolve a few drams of the cyanide in a little water, using a glass rod to stir up the mixture till the solid has all disappeared; and be careful that neither the solid nor the solution touches the skin if it should be in the slightest degree scratched or broken. Now sprinkle plaster of Paris into the solution, a little at a time, and stir all the while. As soon as the mixture begins to set, pour it into your bottle as cleanly as you can – that is, without touching the sides – and press it down with the flat end of a stick if it is not level. Now cork it, and put the bottle away in a cool place till required for use.
This is, I think, the best way of charging the bottle; but there are two other common methods that may, perhaps, be regarded as a little more simple. One is this: put a few small lumps of the 'cyanide' into your bottle, and then cover them with a stiff mixture of plaster of Paris and water, and press down as before. The other plan is to cover the 'cyanide' with a few thicknesses of blotting paper, cut just a little larger than the inside of the bottle. The first of these two methods is fairly satisfactory, but I have always found that the charge, when made in this way, has a tendency to become wet and pasty, in which condition it will spoil the wings of the insects. The other is very objectionable, especially for field work, for the blotting paper fails to keep its place while you are on the chase. If the plaster is used, the mixing must be done quickly and without hesitation, or the mixture will become solid before you can press it into your bottle.
We will not enter now into the
pros