The Butterfly Book. W. J. Holland
Table of Contents
THE CAPTURE, PREPARATION, AND PRESERVATION OF SPECIMENS
"What hand would crush the silken-wingèd fly, The youngest of inconstant April's minions, Because it cannot climb the purest sky, Where the swan sings, amid the sun's dominions? Not thine."
Shelley.
"Do not mash your specimens!"—The Professor.
COLLECTING APPARATUS
Nets.—In the capture of insects of all orders, and especially of butterflies and moths, one of the most important instruments is the net. German naturalists make use of what are known as shears (Scheren), which are made like gigantic scissors, having at the end two large oval rings upon which wire gauze or fine netting is stretched. With this implement, which looks like an old-fashioned candle-snuffer of colossal size, they succeed in collecting specimens without doing much injury. Shears are, however, not much in vogue among the naturalists of other countries. The favorite instrument for the ordinary collector is the net. Nets may be made in various ways and of various materials. There are a multitude of devices which have been invented for enabling the net to be folded up so as to occupy but little space when not in use. The simplest form of the net, which can be made almost anywhere, is constructed as follows: A rod—preferably of bamboo, or some other light, stiff material—is used as the handle, not more than five feet in length. Attached to this at its upper end, a loop or ring made of metal, or some moderately stiff
yet flexible material, should be tied securely. Upon this there should be sewed a bag of fine netting, preferably tarletan. The bag should be quite long, not less than eighteen inches deep; the ring should be not less than a foot in diameter. Such a net can be made at a cost of but a few cents, and will be, in most cases, as efficient as any of the more expensive nets which are more carefully constructed. A good, cheap ring for a net may be made by using the brass ferrule of a fishing-rod. The ferrule should be at least three quarters of an inch in diameter. Into this insert the ends of a metal ring made by bending brass, aluminium, or iron wire into the proper form. When the ends have been inserted into the ferrule, melted solder or lead may be poured into it, and the ends of the wire forming the ring will be thus firmly secured in the ferrule. The ferrule can then be inserted into its mate placed at the end of a bamboo rod. I have commonly obtained for this purpose the last joint or butt of a fishing-rod as the handle of a net. Such a handle can often be purchased for a small sum from a dealer in fishing-rods. It can be made very cheaply. Any kind of a stick, if not too heavy, will do. It is sometimes convenient to have it in your power to lengthen the handle of your net so as to reach objects that are at some elevation above the head, and for this purpose I have had nets made with handles capable of being lengthened by jointed extensions. In collecting in tropical countries, among tall shrubbery and undergrowth, nets thus made, capable of having their handles greatly lengthened, have often proved serviceable. One of the most successful collectors I have ever had in my employment made his net by simply bending a piece of bamboo into the form of the frame of an Indian snow-shoe, to which he attached a handle about a foot and a half in length, and to this he affixed a bag of netting. He was, however, a Japanese, and possessed a singular dexterity in the capture of specimens with this simple apparatus to which I myself never attained. When tarletan cannot be had, ordinary mosquito-netting will do as the material for the bag. It is, however, too coarse in the mesh for many delicate and minute species. Very fine netting for the manufacture of the bags is made in Switzerland, and can be obtained from reputable dealers.
In order to protect and preserve the net, it is well to bind it with some thin muslin at the point where it is joined to the ring. Nets are sometimes made with a strip of muslin, about two inches wide, attached to the entire circumference of the ring, and to this strip of muslin the bag is sewed. For my part, I prefer gray or green as the color for a net. White should be avoided, as experience shows that a white net will often alarm an insect when a net of darker material will not cause it to fly before the collector is ready to bring the net down over the spot where it is settled.
Collecting-Jars.—In killing insects various methods have been used. In practice the most approved method is to employ a jar charged with cyanide of potash or with carbonate of ammonia. For large moths and butterflies cyanide of potash and carbonate of ammonia serve very well, but it must be remembered that carbonate of ammonia bleaches insects which are green in color. It is well, in my judgment, to use a drop or two of chloroform in the jar charged with carbonate of ammonia, for the collection of diurnal lepidoptera. By putting a few drops of chloroform into the jar, the insect is anesthetized, and its struggles are made quickly to cease. The principal objection to chloroform is the fact that it induces rigidity of the thoracic muscles, which subsequently sometimes interferes with handsome setting.
In the preparation of the poisoning-jar it is well to use a jar which has a ground-glass stopper, and the mouth of which is about three inches in diameter. This will be large enough for most specimens. The one-pound hydrate of chloral jars, provided with glass stoppers and sold by Schering, make the neatest collecting-jars that are known to the writer. I have found it well to have such jars partly covered with leather after the fashion of a drinking-flask. An opening in the leather is left on either side, permitting an inspection of the contents of the jar. The leather protects from breakage. At the bottom of such a jar a few lumps of cyanide of potash, about the size of a filbert, should be placed. Over this may be laid a little cotton, to prevent the lumps from rattling about loosely at the bottom of the jar. Over the cotton there is pasted a sheet of strong white paper, perforated with a multitude of holes. In securing the white paper over the cyanide, the writer has resorted to a simple method which is explained in the annexed diagram. 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 (Fig. 47). The paper is punctured over the entire surface included within the inner line, and then, with a scissors, little gashes are made from the outer circumference inward, so as to permit of the folding up of the edge of the disk. A little gum tragacanth is then applied to these upturned edges; and it is inserted into the jar and pasted securely over the cyanide by the upturned flaps. A jar thus charged will last for a long time, if kept properly closed when not in use. Cyanide of potash has a tendency to deliquesce, or melt down in the presence of moisture, and in very humid climates or damp places, if the jar is not kept well stoppered, the cyanide will quickly become semi-fluid, the paper will become moist, and specimens placed in the jar will be injured or completely ruined. It is well, however, to bear in mind the fact 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 some small amount of moisture present in the jar; and in