( Originally Published 1917 )
There are few groups in Nature which offer such advantages to the collector as that of the butterflies. They are easily obtained, easily preserved, and retain their beauty for a long period even under exposure to strong light. They offer opportunities for serious study in which one cannot only review the facts which others have already discovered, but also hope to contribute something of value to the sum of human knowledge.
The mistake most commonly made by beginners with butterflies, as with other collections, is to undertake too much. Instead of starting on the hopeless task of making a collection of the butterflies of the world, it is much better to start with the intention of making a collection of those of one's own town. In the latter case one can hope soon to attain the desired end and then, if one wishes, it is a simple matter to reach out and make a collection of the butterflies of the state or even of the particular region in which the state is located. The natural limitations for a collection in New England is to make a collection of New England butterflies. There is a splendid example of such a collection on exhibition in the museum of the Boston Society of Natural History. This contains representatives of practically every kind that has been collected in New England, and yet there are less than a hundred species in all. So it is apparent that a local collection should be attainable by any enthusiastic student and the very fact that the number of species is limited adds interest and satisfaction to the pursuit.
The main value of any collection of objects lies in the point of view of the collector. The most natural point of view for a beginner is that of the local fauna, as indicated in the previous paragraph. Such a collection best serves as a basis for a study of the subject but it may well lead a broader field through some special phase of scientific interest. Thus while it would be hopeless for most persons to attempt a collection of the butterflies of the world it would be entirely reasonable for one to start a collection of all the species in the world of any given genus or tribe, and such a set of specimens would soon come to possess decided scientific value. Or, instead of the point of view of generic or family relationship, one could take the point of view of special geographical distribution.
Thus a collection of all the butterflies found within a certain number of degrees of the North Pole showing the circumpolar butterfly fauna would have great scientific interest.
There are also various other points of view which could be followed in making a collection. There are already in many of the museums of the world collections of butter-flies which illustrate the various phases of true mimicry e resemblance of one species to another in the same region. This is a field in which one could spend a lifetime of endeavor, and secure results of great value to the world of science. An easier problem for most collectors in the United States would be a collection made from the point of view of resemblance to environment, including such examples as the Angle-wings that show a bark-like set of marks on the under surface. Yet another point of view would be that of hibernation, the making of a collection of all butterflies that hibernate as adults.
These are only a few suggestions. There are many other phases of butterfly life which could be utilized as the basis for interesting collections. The important thing is to have a definite object in view and to make the collection a basis for a real study of the subject, so that the collector will not only be growing intellectually but will also be making a real contribution to our scientific knowledge.
To collect and preserve butterflies in proper condition for study, certain apparatus is necessary. Perhaps the first essential is the collecting net for catching butterflies in the field. The simplest way to obtain this is to buy it of the dealers in entomological supplies, Nets in considerable variety and at various prices are offered in the catalogues of these firms. One can make, however, a net at home with little difficulty. One need only obtain an iron wire about one fifth of an inch in diameter and bend it into a circular ring a foot or fifteen inches wide, leaving the ends projecting at right angles to the circle and having a blacksmith weld them together so as to form a spur about four inches long. Now thrust this spur into some convenient handle, such as a broomstick, and sew over the wire circle a bag of mosquito netting, Swiss muslin, or some similar fabric. It is better that this material be green or black rather than white.
After the butterflies are caught, they must be killed, so some form of killing bottle is necessary. Most collectors use a cyanide bottle, in which the fumes of cyanide of potassium kill the insects. One of the best ways to make this is to place in a wide-mouthed bottle two or three lumps of cyanide of potassium, approximately an inch across. Over his place some fine sawdust and on top of the sawdust, pour liquid plaster of paris carefully so that it will harden into a layer about half an inch thick. Allow the plaster to become thoroughly dry, then insert the stopper into the bottle and it will be ready for use.
It is better to use a ground glass stopper so that the bottle will always be air tight. The sawdust is often omitted, the plaster of paris being poured. directly over the cyanide. The special advantage of the sawdust is that it tends to absorb the cyanide in case it liquefies, as it often does in damp weather. As this cyanide is a deadly poison, it is better to let a druggist prepare the bottle or else to buy it already prepared of the dealers in such supplies.
After the specimens have been killed in the cyanide bottle, some method of keeping them is necessary. The simplest way is to preserve them with their wings closed together in pieces of paper folded over into triangles as indicated on the accompanying diagrams. Such specimens may be kept for an indefinite time and if one wishes to mount them later, it is only necessary to place them for a few hours in a relaxing jar, which is simply a closed vessel with enough water in the bottom to saturate the air with moisture. A great advantage of keeping the specimens in these paper covers is that they require so little room and are easily stored away in tin cans or boxes where they are safe from dust and destroying enemies.
Those butterflies which are to be preserved in the ordinary way, in drawers or cabinets, must be spread out and held in position while the body is drying so that the wings will remain expanded, For this purpose, some form of a setting board is necessary. These may be bought of dealers or made at home. One of the simplest kinds consists of two thin strips of pine board, a foot or more long, nailed to end pieces with a space between the two boards wide enough to accommodate the bodies of the butter-'es. Beneath this open space, a piece of thin cork is tacked. The pin on which the butterfly is fastened is pushed through the cork until the wings of the insect are level with the boards. The wings are then brought forward with a needle point until they are in the desired position and they are then held in place by pieces of glass or by bits of cardboard fastened down by pins. The butterflies must be left in this position until thoroughly dry.
Special insect pins should be used for butterflies. These are longer than common pins and have rounded heads. They are offered for sale by entomological dealers. Instead of pinning the insects and preserving them in cabinets, one may keep them in the Riker mounts, which have the advantage of being sealed so that there is no chance for dust or museum pests to reach the specimens. If one wishes to collect extensively, one will need a considerable number of setting boards and it will be worth while to prepare for them a special drying box like that shown in the picture above.