A very good laurel box may be prepared as follows. Get a small tin box of cylindrical form, measuring about five inches by two, and cut a circle of perforated zinc or wood just the size to fit it snugly as a false bottom without any danger of falling out of its place. Now gather some of the young leaves of the green laurel bush, and beat them almost to a pulp with a mallet or hammer. Place this in your tin box, and press down the perforated false bottom on it. The bruised laurel leaves give off a very powerful odour, which stupefies butterflies immediately.
Fig. 44. – Section of the Laurel Box.
a, space for insects; b, perforated partition; c, bruised laurel leaves.
Of course the reader may be able to think of various other ways in which the laurel box may be made. Any arrangement will do providing the vapour can come to the insects without allowing the leaves to touch their wings; and any ingenious youth could manufacture a more satisfactory article than the one I have mentioned. My desire is, as far as possible, to give instructions that may easily be carried out by anyone, even if he has not the slightest mechanical skill, leaving the clever youth, sometimes, the opportunity of displaying his own inventive power. But in this case I will give a few suggestions concerning other ways in which a laurel killer may be constructed. A firm and fixed false bottom is a decided advantage. This is easily managed by fixing a circular piece of perforated zinc or 'tin' by means of a little solder; or even a wood partition may be used, fixed with a few brads, driven into it from the outside. With the fixed partition, however, you must have a lid at each end of the box. This is easily managed if you get two tins of the same size, knock out the bottom of one, and fit the lid of the other in its place.
I have heard of laurel boxes without any partition save a piece of rag in which the bruised leaves are wrapped. The whole is pressed into the box so firmly that it is not likely to be displaced while you are on the chase. I do not recommend this, for in addition to the chance of its slipping there is a danger of the sap of the leaves exuding through the rag and spoiling the insects' wings. But if the reader should prefer to try this on account of its simplicity, it will probably occur to him that a bottle may be used instead of a tin box.
A well-made laurel box, with a fixed metal partition, is a piece of apparatus strongly to be recommended to all young entomologists who desire to test the relative value of the various poisons that are used by the different experts; for with it any one of these substances can be used. In the poison compartment you can place pieces of 'cyanide' wrapped in blotting paper, or any kind of porous substance moistened with liquid ammonia, chloroform, benzole, or any other volatile liquid insecticide. All the above-named substances are declared to be 'the best,' so they must all be worth the trial.
'Cyanide' is valued on account of its lasting powers. A cyanide bottle well charged will retain its efficiency throughout a whole season. I always recharge two in the spring, one for active service in the field and the other as a reserve force; and these kept in a cool place do good execution throughout the year. If they should exhibit a slight failing, a few minutes' warming before a fire will improve them; but for field work it is better to recharge. At the same time see that the corks are in good condition.
Next to the 'cyanide,' the bruised laurel takes the first rank for permanency; but you must not expect this to last many days. For a few days' continuous work one charge will suffice, but if the laurel box has not been in use for some time you must have a fresh supply.
The liquid poisons, such as ammonia, chloroform, and benzole, are so volatile that they are very powerful for a short time, but so much vapour is lost each time the box is opened that it is absolutely necessary to carry a bottle of the one you use into the field with you. Also see that you have sufficient of the blotting paper or other absorbent to prevent the liquid from leaking through the perforations of the partition.
If you choose ammonia – a substance that is not regarded as a poison, and is therefore easily obtained from any chemist – always get the strongest, and see that it is labelled 'Liq. Ammonia, S.G. ·880' as a guarantee. A small bottle such as you can conveniently carry in the waistcoat pocket will contain sufficient for a day's work. Use only a few drops at a time, but renew frequently. Although the ammonia corrodes cork, yet a good cork is far preferable for the pocket to a glass stopper, for its elasticity prevents it from losing its hold, and the liquid from saturating your pocket and its surroundings; but a glass stopper is certainly better for the stock solution kept at home.
Most of the above remarks apply equally well to benzole and to chloroform, but the latter is so powerful a poison that a very little is required for a day's work, and consequently a very small bottle is more convenient. The dealers in naturalist's appliances supply metal 'chloroform bottles' with screw stoppers and a small nozzle that will allow the liquid to run out only in drops. This is a very good arrangement, since it enables you to avoid the 'drop too much' which is not only unnecessary and therefore wasteful, but saves you from experiencing the disappointment of an empty bottle before your work is half done.
Fig. 45. – The Chloroform Bottle.
Some entomologists recommend the solid carbonate of ammonium instead of liquid ammonia, but this is not so powerful. It must be remembered that we have the butterflies to consider, as well as our own convenience, in the selection of the poisons we use. It is the opinion of many well-known entomologists that 'insects cannot feel pain,' and that we are therefore at liberty to deal with them in any way we please. Still it is as well to save all possible suffering, and be satisfied with no killing box that is not practically instantaneous in its effects.
Among other poisons used by entomologists I may mention sulphur fumes and tobacco smoke. The former may be obtained by burning a little sulphur or a sulphured lucifer match under the perforations of a killing box of the pattern described, and the latter – well, every smoker knows that. I should at once condemn the former method, at least for field work, as troublesome and inconvenient; and as to the other, I have tried the effect of a puff (and many puffs) of tobacco smoke on an imprisoned insect, but was so dissatisfied with the result that I am not likely to do so again.
We have now considered a good many insecticides more or less suitable to our purpose, but there still remains the unsolved problem as to which is the best. Each one has its advantages. For convenience nothing beats the cyanide bottle. It is very speedy in its action, and the use of a bottle is a little preferable to a metal box, for you can always satisfy yourself as to its efficiency without opening it. Cyanide, chloroform, benzole, and some others render the insects more or less brittle and stiff, so that it is not so easy to 'set' them for the cabinet. Perhaps, if you happen to have a supply of growing laurel close at hand, you cannot do better than stick to the laurel box. The time taken in bruising up a few leaves is inconsiderable, and the moisture given off from them will keep your insects moist and supple, or will even 'relax' them if they have become rigid. But try various plans for yourself, and you will be able to settle a question which all the entomologists in the world cannot answer for you – which method answers best in your hands.
The next item for our consideration is the 'collecting box.' This is merely a box in which the butterflies are pinned as soon as they are dead. Here, again, we shall note a few variations from which a selection can be made according to the means or the ingenuity of the reader. For a couple of shillings you can obtain a good zinc collecting box, lined with cork, of oval form (a most convenient shape for the pocket), and quite large enough for one day's captures; and half that modest sum will purchase a wooden box, also lined with cork, adapted to the same purpose.
As with many other things, so with collecting boxes, the cheapest is often the dearest in the end. You may feel inclined to save a shilling by buying a wooden box, but you are sure to discard it after a little practical experience for a metal one. We shall speak a little later on concerning the advisability of 'setting' the butterflies as soon as possible after capture; but this is not always practicable, especially after a good day's catch. Now, if the insects are pinned in a wooden box, they soon become dry and rigid, and consequently cannot be 'set' till they have been put through the more or less tedious process of 'relaxing.' If you use a wooden collecting box you will often find, on a hot and dry day, that all or nearly all your butterflies are rigid before you arrive home; but a metal box will keep them moist and supple, so that you can even put off the setting till the following day if you are unable to do it immediately after your return.
Another point worth considering is the best economy of space. If your collecting box is only about one inch deep inside, you have room for only one layer of pinned insects; but a box only a little deeper may be lined with cork both at top and bottom, and thus be made to accommodate double the number. The zinc boxes sold by the dealers are generally lined with cork in this manner, and are, of course, deep enough for the double layer of specimens; but the wooden boxes are sometimes lined on the bottom only. After these few remarks you will at once see the economy of expending the extra shilling on the former.
Although the prices of collecting boxes are low, yet there are many who would prefer making their own, and there is much to be said in favour of this. A great deal of pleasure is to be derived from the construction of your own apparatus, especially when that apparatus is afterwards to be used in the pursuit of a delightful hobby. During the whole of the time thus engaged, you are looking forward with the most pleasurable feelings to the glorious treat before you, and every joint you make seems to bring you nearer to the realisation of your joys. During the bleak winter months there is no better employment for an entomologist who has a little spare time than the preparation for the next outing. It is just one of those artful schemes by which he seeks to get as much pleasure out of life as it is capable of affording. How many there are who, for the lack of a pleasant and instructive hobby, find their leisure hours the most dismal of all, and who complain of the toil and wearisomeness of their lot! The mournful thought with them is, 'Is life worth living?' but who ever heard such an expression from the lips of an active entomologist?
But I must have done with moralising and proceed to business. The question is – How shall we set to work about the construction of a collecting box? If it is to be a wooden one, select or make a box of such a size as to suit your pocket or satchel, and cover the bottom, and lid too if the depth allows of it, with sheet cork or slices of good wine corks, about one-eighth of an inch thick, fixed on with glue.
The metal box is not quite so easy, but even here you may save yourself much work by keeping your eyes open. Very neat little collecting boxes can be made out of the flat metal boxes in which are sold certain favourite brands of tobacco. Some of these are just the right depth, and also of a very convenient size for the coat pocket. Beg one of these boxes from a smoking friend, and if the lid is not held by a hinge (a great advantage, by the way), you can easily solder on a brass one.
All that remains now is the fixing of the cork. Buy a sheet of cork at a naturalist's shop, this being a commodity always in stock, and cut out two pieces just the size to cover the bottom and the lid.
Gum and glue are not very satisfactory as fixing agents, for, as you will presently learn, there are times when it will be necessary to keep the box moist, and moisture softens both these substances. The cork must be fixed by means of little strips of metal. Here are two ways of doing this:
First. – Cut a few little strips of sheet tin, each about two inches long and one-eighth wide. Double and bend them as shown in fig. 46, and solder them to the surfaces which the cork is to cover (fig. 47). As the cork is pushed in its place, these little slips are allowed to force themselves through slits in it made by means of a penknife, and then the ends are bent over as shown in fig. 48. Two or three such fasteners will be quite sufficient to hold down each sheet of cork.
Fig. 46.
Fig. 47.
Fig. 48.
Fig. 49.
Second. – Put the sheets of cork in their places first, then make a few little slits through both metal and cork with the point of a penknife, and then bind the two together with a few ordinary paper fasteners. This arrangement is shown in section in fig. 49.
Just one point more concerning the metal collecting box. You will often call moisture to your aid in keeping the butterflies flexible and soft. This will have but little action on zinc, but will sooner or later cause the 'tin' (really tinned iron) box to rust. Here, then, is a point in favour of zinc, but still a home-made 'tin' collector will last a long time if kept dry when not in use.
As already hinted, there are times when it is desirable to take home certain butterflies alive, either for a study of their movements or for the purpose of securing eggs for breeding. To this end you must provide yourself either with a number of 'chip boxes' with a few small holes pricked in the cover, or with some metal boxes with perforations for the admission of air. If the latter, you will have no difficulty in securing a few 'tin' boxes of suitable size, but, as the surface of the metal is very smooth, you should always introduce a few leaves or something else that will provide a foothold for the inmates.
The last item of the outfit is the pins. Ordinary draper's pins are quite out of the question. They are far too thick and clumsy for the collector's work. If you are not already acquainted with the 'entomological pins,' you had better ask a dealer to give you a sample card. This will be very useful for reference until you become well acquainted with the various lengths, thicknesses, numbers and prices. The card will contain one of each kind, with price and number attached.
If you fix a butterfly with the ordinary pin, you may find the latter partly covered over with verdigris after a time. This bright green substance is formed by the action of decomposing animal matter on the copper of the pin, and gives a very unsightly appearance to the specimen. To avoid this the entomological pins are either silvered, blackened or gilded. The silvered pins tarnish after a time, but the two other kinds keep their colour well, and are therefore better. The gilded ones are rather expensive and unnecessary, and perhaps the black ones are to be preferred to the silvered, although they are rather more costly.
Most dealers will supply you with a box of mixed pins, each box containing about six different sizes. This is very convenient for those who work in a rather small way; but if you intend to make entomology a prolonged study you had better get an ounce or so of each of the more useful sizes.
Butterflies vary much in size, and Nos. 3 to 8 are the most useful sizes of pins to fix them; No. 3 being for the largest, and 8 for the smallest.
Supposing all the foregoing requisites to be quite ready, still you are really by no means prepared for all your work. The butterflies captured should be set as soon as possible after your return, and everything required for this part of the work must be in perfect trim. Yet I think it will be more convenient just now to confine our attention to the subject of 'Catching Butterflies,' leaving all the indoor work to form the substance of another chapter. Our next point, then, shall be the consideration of seasons, times, and localities.
The earliest of the butterflies make their appearance on the wing in April, or, if the weather is mild, towards the end of March; and from this time you can find employment up to the end of September or the beginning of October – a period of about seven months. But it must not be supposed that all parts of this long season are equally prolific, and will yield equally valuable catches. Remember the short term of a butterfly's life, and bear in mind that each one has its own regular season in which to spend the winged state; you will then see that anyone who wishes to 'work' as many species as possible must arrange his outings in accordance with the insects' own times.
Some butterflies are double-brooded, and the two broods may not come forth at certain fixed times. Hence they seem to be on the wing almost without cessation for several months together, and therefore need not have a special day set apart for them. But others are more uniform in their date of appearance, and die off at about the same time. To catch such as these you must be careful to watch the weather, make allowance for any severities that may tend to cause a delay, or an unusually high temperature that may hasten their emergence, and then select a day in which you may expect to find them fresh and unworn. A week too early, and none are to be seen; a week too late, and nearly all you catch are worn and worthless.
A glance at our Calendar (Appendix II) will give you a few illustrations in point. Thus you will observe that May is a month for the 'Whites,' early 'Blues' and certain of the Fritillaries; July for most of the Hairstreaks and Browns, and so on. Before you have been long collecting you will have captured the very common species, and then you will find that your butterfly hunts are very unproductive unless you make it a point to try for certain species at the proper times.
Time, however, is not the only thing to take into account when preparing for a day with the butterflies. It is equally important that we should carefully select our locality in accordance with the known haunts of the various species. As long as you are simply working up the common kinds, you may wander almost at random in waste places, flowery meadows, corn fields, railway banks, &c.; but when you have secured a few specimens of each of these, you must search out the favoured resorts of the more local and the rarer species. For instance, wooded spots must be visited if you are to take certain of the Fritillaries, oak woods for the Purple Emperor and the Purple Hairstreak, fenny districts for the beautiful Swallow-tail, and so forth. In some cases the butterflies are closely restricted to certain isolated localities, to which you must travel if determined to obtain them.
There yet remains another important matter to consider, and that is the kind of day you shall select for your outing. Butterflies are not only strictly day-fliers, but most of them venture out only on bright days. Always choose as hot a day as possible, with a very bright sun. If you are to be out for a full day's collecting, manage to be on the hunting ground at about ten o'clock in the morning. As a rule there are not many out before this time, and some do not appear to stir till an hour later: still there are a few 'early birds' among them, one of which – the Wall Butterfly – I have seen on the wing before eight.
If your season, your day, and your locality are all well chosen, you may reckon on a good six hours' work. At about four the butterflies begin to lag, and then drop into their hiding places, one by one, till only a few of the late stragglers remain on the wing.
So far I have furnished some general instructions that may be regarded as preparatory to the start; but I will now give a few hints as to the mode of procedure when the day for field work has come.
First, see that you have secured all your apparatus, and that it is in perfect condition. What is more annoying than to find, after you have travelled some miles to get to your hunting ground, that you have left your screw ferrule at home, or that the soldering of your metal Y is just giving way? If you are troubled with a short memory, it will be advisable to make out a list of every requisite for your field work, and keep this for reference on all field days.
Here is a list of your equipment for a day with the butterflies. Net, ferrule or Y, stick, collecting box (the cork of which should be damped if the box is a metal one), a few 'chip boxes' for live insects, killing apparatus, a good supply of pins of several sizes, a piece of string, needle and cotton, and your penknife.
You observe in this list one or two items not previously mentioned, since they hardly come under the category of apparatus, but a moment's thought will convince you of their usefulness, especially in the case of a breakdown. If your net catches in a thorn – a very common occurrence – and a big rent is made, the needle and cotton will save you a deal of agony, and perhaps loss of temper. If your stick breaks under your exertions, the knife or the string may prove a most valuable companion. Your pins may be stuck in the cork of your collecting box, certainly the most convenient spot for immediate use; but you may also have a reserve store in a small pocket cushion, or arranged neatly on a strip of flannel which can be rolled up in the waistcoat pocket.
At last you are on the hunting ground, fully equipped but inexperienced, and at first find yourself just a little awkward in the use of your new gear. Your experience with the cap has been a very wide one, and you are possibly an expert at knocking down 'Whites' in the streets and in your neighbour's kitchen gardens. Now you have to wield the net, and coax your captives into your killing bottle; hence a slight feeling of incompetence at first.
You soon get over this, however, and within five minutes you may be seen furiously slashing away at all the poor butterflies that come within range, common 'Whites' and dingy 'Browns' receiving as much attention at your hands as any rare gem that may happen to cross your path.
How different are the movements of an experienced collector! He walks stealthily along the route he has chosen, apparently taking but little notice of the majority of butterflies that approach and pass him. He has already secured his 'series' of nearly all the species, and is carefully on the watch for the gems that are required to complete his cabinet. His actions are slow and deliberate rather than rash; and he trusts more to his eyes than his legs.
The beginner may take to his field work quite to his own satisfaction, and may travel homeward with a feeling of great pride over his first day's catch; but yet there are a few points in which a little advice may not be quite out of place, particularly so with regard to the management of the net, and the killing and pinning of the insects.
Most of the butterflies may be caught on the wing, and it is far better to net them in the air than to sweep them off the herbage and flowers. If these are rather low, you should strike the net smartly upwards from below them, but of course this movement is impossible with insects that happen to be almost above your reach. If a butterfly is busily engaged in searching out its sweet food, flying from flower to flower, don't think of giving chase, but follow it up stealthily, and you will sooner or later get an opportunity of striking at it while in the air. Sometimes, however, you will see a powerful flier making a straight dash across your field, taking no notice whatever of the fragrant blossoms, but evidently engaged on some important errand. If such happens to be a species you require, then you must run for it, but you will probably be satisfied with only a few chases of this kind, particularly if the sun is very hot, and the ground diversified with clumps of furze, heather, 'molehills,' and ditches.
There are times when your only plan of netting a butterfly is to sweep it from a flower or leaf on which it has settled. If the vegetation is very low, you have simply to bring the net down upon it, and then, holding up the apex of the net with the other hand so as to give it room to fly, you can inclose it by grasping the lower part of the net as soon as the butterfly has fluttered upward. If the herbage is tall it is advisable to strike either upward or sideways at the insect, starting it from the leaf or flower on which it rests; for if you bring down the net you will have to inclose the whole or part of the plant on which the butterfly has settled – a procedure that often ends in a torn net, or in the insect becoming damaged through being rubbed against the plant.
Whenever you capture a butterfly by a sweep of the net through the air, you immediately turn the ring into a horizontal position, so that the bag of the net closes itself as it falls over the edge. This gives you an opportunity of examining the insect before you introduce your killing bottle. This is a very necessary precaution, for you are generally unable to judge of the condition of a butterfly while on the wing, and in some cases you cannot even be certain of the species. If, then, you were to call the killing bottle into requisition for every capture you make, you would certainly find yourself taking the life of many an insect that is of no use whatever to you. Always examine your specimens at the moment they have been secured, at least as far as it is possible to do so, by looking through the gauze; and let your examination be as brief as possible, or some of the butterflies that were at first in splendid condition will render themselves useless to you during their struggles to get away.
When satisfied that an insect is likely to be of value to you, keep it in the apex of the net by grasping the bag beneath it with the left hand, and then introduce the opened killing bottle with the other hand. As a rule you will experience not the slightest difficulty in coaxing it into its trap, and then you quickly cover the mouth of the killing bottle with the gauze, then apply your left hand, using it as a temporary stopper for a few seconds, and now, the insect having been quieted, replace the cork.
A good killing bottle is almost instantaneous in its action, not only stupefying, but immediately killing the insects; and as soon as you are sure that each specimen is quite dead, you may pin it in your collecting box.
You must be cautious, however, on the one hand, that you do not take it out too soon. If you do you may find that it recovers from the mere stupefying effect of the poison, even after it has been pinned, and when you open your collecting box for the next butterfly, you are horrified at the sight of the poor victim struggling to free itself.
On the other hand, don't keep the insects in the killing bottle too long. If you do you will soon have a number, one lying on another, and all tumbled about together while you are on the chase. Of course, under such circumstances you are sure to damage them more or less.
Many collectors, although they may always use a killing bottle for moths, never employ one for butterflies, but kill them by pinching the thorax. It is well to know how to do this, for it sometimes turns out to be a really quicker process than that we have just been considering; and, more than this, you can resort to it should you break or lose your bottle while in the field. It is done in this manner: Bring the two opposite sides of the net together, closing them on the insect so that it cannot flutter. If now the wings are brought together over the back, all is right, but if not, give it just a little room to flutter till you have the opportunity of closing the gauze upon it with the wings in the desired position. Now pinch the thorax smartly between the finger and the thumb, applying the pressure outside the net, but be careful not to squeeze the abdomen. In a moment you will find the insect quite dead, and not in the least damaged unless you performed the operation clumsily.
Now as to pinning. Hold the dead butterfly between the finger and thumb of the left hand, and pass a pin of convenient size through the centre of the thorax above, and push it through so that the point appears centrally on the under surface. It is now ready for your collecting box.
So you work on till the sun begins to get low, and the butterflies become fewer and fewer, till only a few stragglers of common species are to be seen. Still there are a few hours of daylight and perhaps even of bright sunshine before you, and if you are not weary with the work done, you may very profitably spend these hours in the collection and study of the habits of moths.
Catching Moths by Day
The reason for choosing the sunny hours for butterfly collecting is obvious, all these lovers of brightness being then actively on the wing; and although many may be driven out of their hiding places by beating the herbage with the handle of your net, or even be searched out as they rest on stalks and leaves during dull days or at morning and evening twilight, yet such methods are comparatively tedious and unproductive.
Some moths also are lovers of sunshine, and while engaged in butterfly hunting you will often meet with a moth flying briskly from flower to flower and taking its fill of both sweetness and brightness. Again, as you wade among flowery herbs in quest of butterflies you will certainly disturb a number of moths, causing them to take a short flight in search of a safer spot. Thus you will almost invariably find a few moths among the contents of your collecting box even though you made no special effort to seek them out. But we shall now see how we may set to work to obtain a successful catch of moths at times when butterflies are not so much in demand, or during the less brilliant hours of the day, when butterflies are at rest.
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