Insects are prepared for the cabinet by being mounted upon pins and "expanded." There are various sorts and sizes of insect-pins, but those made by Klaeger, of Berlin, are generally preferred at the present time by the leading entomologists of the world. The French pins and the so-called "Carlsbader pins" are too long and the points are too fine, and, therefore, too likely to be injured to make them desirable. The English pins are too short, and except in the case of very small insects, are not used by the best collectors. Insects should be mounted high upon the pin, i.e., in such a way that not more than one-fifth or at the most one-fourth of the pin shall be exposed above the body of the specimen. Dr. Staudinger, the celebrated lepidopterist of Germany, makes it his rule to mount all his specimens in such a way that the wings are elevated upon a plane one inch above the tip of the pin. The writer has had the greater part of his collection, of over fifty thousand specimens of lepidoptera, mounted at an average height of seven-eighths of an inch above the points of the pins. The "English method" of mounting low down, and only leaving enough of the pin exposed below to permit of fixing the specimens in the cork at the bottoms of the drawers of the cabinet, is rapidly passing out of vogue, even in England, and is giving place to the "Continental Method." Insect pins are of various sizes; adapted to the size of the insect which they are to carry. The most serviceable sizes and which will be proportioned to the majority of the insects which the collector is likely to take, are Klaeger's No. 3 and No. 5. For very large insects higher numbers may be employed, and for smaller insects lower numbers, though in the case of the latter it is perhaps better to use the short English pins and then to mount the specimens upon the bits of cork or pith which are themselves mounted upon the longer German pins. Such mounts are known as "double mounts" (see Fig. 96). The writer desires to utter a caution against the use of the common black insect-pins so often sold by dealers, and the sole stock in trade of one or two firms of opticians in this country. They are very liable to rust at the point and to bend, and are totally unsuited for use in humid, tropical, and semi-tropical climates, or for collections which are to be transported far over the seas. Beetles should always be pinned through the right elytron. Bugs should be pinned through the scutellum, as the small triangular piece between the elytra is called. All other insects should be pinned in the middle of the thorax, and care should always be taken to set the pins perpendicularly.
[a]Fig. 96.]—Double Mount. C, Long pin; P, pith; S, specimen mounted on short pin; L, label.
[a]Fig. 97.]—Frame for Mounting Beetles. a, a, Wooden frame; A, B, paper drumhead.
Having pinned the specimen the next step is to expand it properly. In the case of beetles this is done by simply arranging the feet and the antennæ in such a way that they can easily be inspected. In doing this it is well to have a frame seven-eighths of an inch deep, or thereabouts, backed by a thin piece of soft pine, and covered on top by a sheet of paper, which has been first moistened and then pasted around the edges, and which when dry expands like a drumhead. (Fig. 97.) Upon this a number of beetles may be pinned, their feet drawn out, and there be left to dry. In the case of lepidopterous insects, and other insects having considerable expanse of wing, setting-boards are required. These are boards provided with a groove in the middle capable of receiving the body of the insect, and permitting of the expansion of their wings laterally. These boards should be of various widths, so as to be adapted to insects having various expanse of wings, and the grooves also should be of various depths, adapted to insects having bodies of various size. The best form of a setting-board, with which the writer is acquainted, is that given in Fig. 98. The narrow slit below the groove, which is intended for the reception of the body of the insect, admits of passing the pin down to a proper depth, and the depth is regulated of course by the piece at the bottom of the setting-board. The two side pieces should always be from seven-eighths of an inch to an inch thick. The best material is soft, clean pine, or, better still, the wood of the Kiri-no-Ki (Paulownia regalis).
[a]Fig. 98.]—Setting-Board.
[a]Fig. 99.]—Setting-Board. (After Riley.)