The collector having provided himself with a net for capturing insects must also provide himself with one or more collecting jars. It is well to have several of these of a size convenient for carrying in the pockets. For large specimens a larger jar is required; for small specimens a smaller receptacle is better. The larger jar should have the mouth about two and one half or three inches in diameter. Wide-mouthed glass phials an inch and a half in diameter serve best for the smaller receptacles. The stopper of the larger jar should be of ground glass, of the smaller jar of good cork. Jelly tumblers or glasses with tin tops make good collecting jars. In preparing the jar for use place a few lumps of cyanide of potash about the size of a filbert at the bottom; then put in a little clean sawdust to keep the pieces of cyanide from rattling about; over the lumps of cyanide paste a sheet of strong white paper perforated with a multitude of holes. In doing this the writer has resorted to a simple method, which is explained in the diagram on [Plate D], Fig. 4. A piece of paper is placed under the jar and a circle the size of the inside of the jar is traced upon it. Then a disk is cut out about three quarters of an inch greater in diameter than the original circle. The paper is punctured over the entire surface included within the inner line, and then with scissors little gashes are made from the outer circumference inward, so as to permit of folding the edge of the disk inwardly. A little gum tragacanth, or paste, is then applied to these upturned edges, the disk is then inserted into the jar and pasted securely over the cyanide by means of the upturned flaps. A jar thus charged will last for a long time if kept stoppered when not in use. Cyanide has a tendency to liquefy in the presence of moisture, and it is well therefore to take care to keep the jar closed when not in use. It must, however, be borne in mind that the fumes of hydrocyanic acid (prussic acid), which are active in producing the death of the insect, will not be given off in sufficient volume unless there is a small amount of moisture in the jar, and in very dry climates the writer has sometimes found it necessary to moisten the bottom of the jar with a drop or two of water. Jars also may be charged with lumps of carbonate of ammonia, but as this substance bleaches the wings of insects, especially those which are green in color, its use is not strongly recommended. Figure 5 on [Plate D] shows a jar prepared for use.

When a butterfly has been caught in the net it is apt to flutter about and struggle violently, thus injuring its wings. It is well therefore as soon as the insect has been captured to take hold of it at the point where the wings join the body, while it is still in the net, and by gently pinching the thorax to disable the insect. The fingers are applied from the outside, as shown in the illustration (see [Plate D], Fig. 1). Then the collector, unstoppering his jar, inserts it into the net and allows the butterfly to drop into the jar. Butterflies belonging to the family of the Hesperiidæ, or “skippers,” are best captured in the net by holding up the end of the bag. The insects will then fly upward and settle near the top of the bag. The collector puts the open jar with his right hand into the ring of the net and holding the bag with the left hand brings the jar under the butterfly, and then claps his left hand over the mouth of the jar, thus securing the insect in the jar, where after a couple of seconds it will be stunned by the fumes and fall to the bottom. Death is speedy, but not instantaneous, and the insect should be allowed to remain a little while in the jar. Having been asphyxiated by the fumes of the jar, the insect may then be removed and either mounted upon a pin and transferred to a collecting box, which will presently be described, or put into an envelope. It is well not to accumulate too many insects in the collecting jar, as those which are caught later will injure in their struggles those which have been caught first. I make it a rule to rapidly transfer the insects from the collecting jars to the collecting boxes which I carry with me. The preservation of specimens in perfect freshness, without torn or ragged wings, is of the utmost importance, and it is better to take fewer specimens, preserving them in immaculate condition, than to accumulate a quantity of ragged and battered examples. The old adage, “Practice makes perfect,” applies in the use of the net and the poisoning jar. There will necessarily be some failures on the part of the young collector at the outset, but if he is neat and quick of finger he will soon acquire the art of taking and preserving perfect specimens.

The field box should be made of tin and should have a sheet of cork securely fastened at the bottom. In one corner of the box, tied in gauze and securely fixed in place, there should be a few lumps of cyanide. Into this box the specimens should be pinned as they are taken from the collecting jar, and the lid of this box should be kept tightly closed most of the time, being opened only when the transfer of the pinned specimens to the interior of the box is ready to be made. Inasmuch as pinning insects on the field is not always satisfactorily accomplished, the writer prefers not to pin them, but to carry with him a supply of small pay-roll envelopes, into which the insects are put, and these envelopes are then put into a box which has some cyanide secured in it, as has already been described. The writer also carries with him a little phial of chloroform in his vest pocket, and he sometimes uses this to stun insects or puts a few drops into the collecting box and then closes it. The objection to the use of chloroform is that it induces spasms of the thoracic muscles, and butterflies killed by the use of chloroform are not nearly so easily mounted as specimens which have been killed with cyanide. Beetles, wasps, and other hard-bodied insects should not be put into the same collecting jars as those which are used for butterflies, as they are very apt to injure the latter, tearing and spoiling the wings. If the collector is engaged in taking other insects besides butterflies and moths, he should have special jars in which to put the beetles and other hard-bodied and spiny things.

If the collector does not wish immediately to mount his specimens, but to preserve them for mounting at a future time, they may be left in the envelopes of which I have spoken, or may be “papered.” The simplest way of putting up butterflies in papers is to take an oblong piece of any kind of moderately good paper and fold it as indicated in the diagram (see [Plate E], Fig. b), first folding on the line a-b, then on a-d and c-b; then on the lines b-f and e-a, as marked in the diagram. The result is the enclosure of the insect as shown in [Plate E], Fig. c. A hundred or more of such envelopes may be put into an ordinary cigar box. Such boxes, filled with butterflies, in order to prevent mould and the ravages of pests, should have some chloroform or carbon bisulphide put into them and afterward a spoonful or two of naphthaline crystals. Then they should be closed and sealed up by pasting strips of paper over the edges. Butterflies thus collected on journeys may be safely carried for long distances without injury, or even transmitted through the mails provided the boxes are strong enough to resist crushing. When on journeys the writer of these paragraphs always papers his specimens, bringing them home to be later carefully mounted at his leisure. It is of the utmost importance to note on each envelope the place and the date of capture, so that these may later be placed upon the little labels or tickets which are put upon the pins after the insects have been expanded and mounted for display.

MOUNTING BUTTERFLIES

The writer cannot do better in dealing with this subject than to transfer from “The Butterfly Book” the substance of the directions there given in relation to this matter.

When the collector has time enough at his disposal he should at once mount his specimens as they are intended to be displayed. The insect should first of all be pinned. For this purpose “insect pins” should be used. These are made either of soft steel or of pin metal. The first are to be preferred, except in very damp climates, where they sometimes rust if they have not been properly enamelled with shellac. The pin should be thrust perpendicularly through the thorax, midway between the wings, and at a considerable elevation upon the pin. It should then be placed upon the setting board or setting block. Setting boards or setting blocks are pieces of wood having a groove on the upper surface of sufficient depth to accommodate the body of the insect and to permit the wings to be brought to the level of the upper surface of the board (see [Plate D], Figs. 6 and 7; and [Plate E], Figs. d, e, f). They should also be provided either with a cleft or a hole which will permit the pin to be thrust down below the body of the insect for a considerable distance. As a rule the wings of all specimens should be mounted at a uniform elevation of about seven eighths of an inch above the point of the pin. This is known as the “continental method” of mounting, and is infinitely preferable to the old-fashioned “English method,” in which the insect was pinned low down upon the pin, so that its wings touched the surface of the box.

EXPLANATION OF PLATE E

Fig. a. Vivarium, or cage in which to breed caterpillars. a, base, kept even by cleats, g, g; on this is placed a pan 4 inches deep made of sheet zinc, and filled with earth; to the middle is soldered a tube of zinc, into which a large bottle fits; the bottle is filled with water to keep the plants placed in it fresh and green; b, outer case, with sides of glass, fitting closely about the zinc pan; c, top, covered with wire-cloth, rabbeted on b, and easily lifted off.
Fig. b. Diagram showing way to make paper envelopes for butterflies.
Fig. c. Envelope folded with butterfly inside.
Fig. d. Stretching board for expanding moths and butterflies. Strips of tracing-muslin are used on this to keep the wings down, paper will also serve the purpose.
Fig. e. Stretching board, showing how wings may be held in place by pieces of thin cardboard.
Fig. f. Showing the way in which the antennæ and body may be held in place with insect pins while the insect is drying.