CHAPTER VI.

PRESERVING SPIDERS, GALLY-WORMS, AND INSECTS.

SPIDERS.

The general directions which we shall give respecting Insects, hold good as to Spiders, only we must mention there is considerable difficulty in preserving the bodies of Spiders, which generally, in a very short time, shrink into a shapeless mass. To prevent this, the body should be pricked with the triangular awl and the contents pressed out; it should then be stuffed with very fine carded cotton or down, which can be pushed in by a pricker, blunted a little at the point. When properly distended, the small aperture should be filled up with a little cement, or a solution of gum-arabic. The legs of the larger species, such as the Bird-catching Mygale and the Scorpions, are also liable to shrink, and should be stuffed in the same manner as that of the body.

In those species of Spiders which we have thus prepared, and whose colors are rich and likely to be affected by the action of the atmosphere, we must endeavor to arrest its progress by immediately imbuing the animal, after it is set up, with the solution of corrosive sublimate, and in an hour after with a thin coating of a very weak white-spirit varnish; for this purpose, take a tea-spoonful of the ordinary white-spirit or elastic varnish, and add to it two tea-spoonfuls of spirit of wine; apply this wash with a fine camel-hair brush, which will quickly dry, and have a strong tendency to preserve the color. The varnish, being thus reduced in strength, will not leave any gloss on the insect, nor will it be at all perceptible.

Mr. Samouelle, author of "The Entomologist's Useful Compendium," in speaking of preserving Spiders, says: "The best preserved specimens that I have seen are those where the contents of the abdomen have been taken out and filled with fine sand. I have preserved several in this way, and find it answers the purpose."

Mr. Donovan makes the following observations on the preservation of Spiders:

"To determine whether some species of Spiders could be preserved with their natural colors, I put several into spirits of wine; those with gibbous bodies soon after discharged a very considerable quantity of viscid matter, and therewith all their beautiful colors; the smallest retained their form, and only appeared rather paler in the other colors than when they were living.

"During the course of last Summer, among other Spiders, I met with a rare species; it was of a bright yellow color, elegantly marked with black, red, green, and purple; by some accident it was unfortunately crushed to pieces in the chip-box wherein it was confined, and was, therefore, thrown aside as useless; a month or more after that time I observed that such parts of the skin as had dried against the inside of the box retained the original brightness of color in a considerable degree. To further the experiment, I made a similar attempt, with some caution, on the body of another Spider, and, though the colors were not perfectly preserved, they appeared distinct.

"From further observations I find, that if you kill the Spider, and immediately after extract the entrails, then inflate them by means of a blow-pipe, you may preserve them tolerably well; you must clean them on the inside no more than is sufficient to prevent moldiness, lest you injure the colors, which certainly, in many kinds, depend on substance that lies beneath the skin."

Scorpions, and all the Spider tribe, may be sent home in spirits, which will preserve them perfectly, and when taken out and dried, they will be found to have suffered nothing from their immersion. We have seen some specimens sent up, after being sent home in spirits, which rivaled any which have been preserved in a recent state. The animals of this class are particularly liable to the attacks of insects, particularly in warm countries, on which account the mode of transporting them and keeping them in spirits is, perhaps, superior to all others. If, however, they are set up in a warm climate, they should be well soaked with the solution of corrosive sublimate, made according to the recipe of Mr. Waterton.

For the setting up of this class, see the directions for preserving insects.

INSECTS.

Every country of the world is replete with this extensive and interesting class of beings, whose forms are infinitely diversified, and whose species are the most numerous of any class in the animal kingdom.

Before any attempt is made to collect insects, certain apparatus must be provided, not only to enable us to secure them, but also to preserve them after they are caught.

First, then, we must be provided with a quantity of wooden boxes, from 18 to 20 inches long, 15 to 17 inches wide; and two inches deep. These should have well-filled lids, with hinges, and fastened by a wire catch, or small bolt. The bottom should have a layer of cork, about the sixth of an inch in thickness, which should be fixed down with very strong paste, made according to our recipe; and also some wire nails, to prevent it from springing. Over the cork should be pasted white paper. The box should be anointed inside with oil of petroleum. If that cannot be procured, make an infusion of strong aromatic plants, such as cinnamon, aloes, thyme, laurel, sage, rosemary, or cloves, and wash the inside with it. A small packet of camphor should be wrapped in a piece of rag, and deposited in a corner of the box.

We must also be provided with a quantity of _Insect pins_, of different sizes, corresponding with the size of the insect. The pins used for setting should be longer than those which are taken to the field.

Bottles, with mouths from an inch and a quarter to two inches in diameter, must also be procured, and these must be three-fourths full of spirits, such as weak brandy, rum, gin or whisky.

HUNTING-BOX.--We must besides have what is termed a hunting-box, for carrying in our pocket, when seeking after insects. This should be made of strong pasteboard or chip, for lightness, or, if this is no consideration, of tin. It must be of an oblong-oval shape, rounded at the ends, for the convenience of the pocket. It should be from eight to ten inches long, four to five inches wide, and two and a half to three inches deep. It must have a layer of cork both in the bottom and top of the lid, inside, for attaching insects to, when caught during the day. The larger insects are placed at the bottom, and the smaller ones on the lid.

THE ENTOMOLOGICAL.--We next procure a net, constructed similar to a bat-fowling net. This is either made of fine gauze or coarse muslin; it may either be green or white--the latter is the best for observing small insects which may be caught; the green, however, is better adapted for catching Moths. The net-rods should be made of hickory, beech, hazel, or holly; they ought to be five feet in length, quite round, smooth, and tapering to an obtuse point; the oblique cross-piece at the point should be of cane, and fitted into the angular ferule; the rod must be divided into three or four pieces, so that it may be taken asunder and carried in the pocket; the upper part of each joint must have a ferule affixed to it, for the purpose of articulating the other pieces. Each joint should have a notch or check to prevent the rod from twisting.

The net itself, must have a welting all around it, doubled so as to form a groove for the reception of the rods. In the center of the upper part or point it must have a small piece of chamois leather, so as to form a kind of hinge; this must be bound round the welting, and divided in the middle, so as to prevent the cross pieces from slipping over each other; it shows about four inches of the gauze turned up, so as to form a bag; there are strings for the purpose of passing through the staple, to which the net is firmly drawn on each side. When the net is used a handle is to be held in each hand.

If it is intended to take insects on the wing, by means of this net, for which it is admirably adapted, it may be folded together in an instant. If the gauze is fine enough, and preserved whole, even the smallest insect cannot escape. It may be also applied in catching Coleopterous Insects, which are never on the wing, as well as Caterpillars. When used for this purpose the Entomologist must hold it expanded under trees, while another must beat the branches with a stick. Great numbers of both insects and larva will fall in the gauze, and by this means many hundreds may be captured in a day.

Another method is to spread a large table-cloth under trees and bushes, and then beat them with a stick. An umbrella reversed has frequently been used for the same purpose. Bose, the celebrated naturalist, used this last method--he held the umbrella in the left hand, while he beat the bushes with the other.

THE HOOP OR AQUATIC NET.--This net is used for capturing Aquatic Insects, which are either lurking at the bottom, swimming through the liquid element, or adhering to plants. It may also be successfully used in sweeping amongst grass and low herbage, for Coleopterous Insects, and others which are generally to be found in such situations. The socket for the handle may be made of such dimensions as will answer the second joint of the Entomological net-rod, which will save carrying another handle; or a walking-stick may be made to fit it.

A VIAL.--This may either be made of tin or crystal, and used for collecting Coleopterous and other Creeping Insects. The mouth should be nearly an inch wide, and a cork exactly fitted to it, in the center of which must be inserted a small quill, to afford air, and inserted about an inch beyond the cork, to prevent the insects from escaping. If the bottle is made of tin, and of a larger size, a tin tube must be introduced into its side, and terminating externally at the surface.

A DIGGER.--The instrument is either made of iron or steel, and is about six or seven inches in length, fixed into a turned wooden handle. It is used for collecting the pupae of Lepidopterous Insects, at the roots and in the clefts of the bark of trees; and also for pulling off the bark, particularly from decayed trees, under which many curious and rare insects are frequently found. It is most useful with an arrow-headed point.

SETTING NEEDLES.--Fitted into a small wooden handle, the needle itself should be about three inches long, and about the thickness of a small darning-needle slightly bent from about the middle. A straight needle is used for extending the parts of insects; at one end of the handle is the needle, and at the other a camel's hair pencil, which is used for removing any dirt or dust which may be on the insects. The pencil may be occasionally drawn through the lips, brought to a fine point, and used for disposing the antennæ and palpi of insects of the minute kinds.

SETTING-BOARDS.--These must be made of deal board, from a foot or fifteen inches long, and eight or ten inches broad, with a piece of wood run across the ends, to prevent them from warping. They are covered with cork, which must be perfectly smooth on the surface, with white paper pasted over it. Several boards will be required, by persons who are making collections, as some of the insects take a considerable time to dry, so that they may be fit for introducing into a cabinet.

The boards should be kept in a frame made for the purpose. It should consist of a top, bottom, and two sides; the back and front should have the frames of doors attached by small hinges, and their centers covered with fine gauze, for the free passage of air; the sides should have small pieces of wood projecting from them, for the boards to rest on; which should be at such a distance from each other that the pins may not be displaced in pushing the boards in or drawing them out. The frame should be placed in a dry, airy situation.

BRACES.--These are merely small pieces of card, cut in different forms, attached to the butterfly and other insects. They are pinned down on the insects, to keep their wings, etc., in a proper state, till they acquire a set.

THE EGGS OF INSECTS.

The eggs of insects preserve their form and color in a cabinet, in general, without much trouble. Swammerdam had a method of preserving them when they appeared to be giving way. He made a perforation within them with a fine needle, pressed out their contents, afterwards inflated them with a glass blow-pipe, and filled them with a mixture of resin and oil of spike.

THE LARVÆ, OR CATERPILLARS.

The easiest way of destroying the Caterpillar is by immersion in spirit of wine. They may be retained for a long time in this spirits without destroying their color.

Mr. William Weatherhead had an ingenious mode of preserving Larvæ. He killed the Caterpillar, as above directed, and having made a small puncture in the tail, gently pressed out the contents of the abdomen, and then filled the skin with fine dry sand, and brought the animal to its natural circumference. It is then exposed to the air to dry, and it will have become quite hard in the course of a few hours, after which the sand may be shaken out at the small aperture and the Caterpillar then gummed to a piece of card.

Another method is, after the entrails are squeezed out, to insert into the aperture a glass tube which has been drawn to a very fine point. The operator must blow through this pipe while he keeps turning the skin slowly round over a charcoal fire; the skin soon becomes hardened, and, after being anointed with oil of spike and resin, it may be placed in a cabinet when dry. A small straw or pipe of grass may be substituted for the glass pipe.

Some persons inject them with colored wax after they are dried.

THE PUPA.

When the insects have escaped from their Pupa skin, the skin usually retains the shape and general appearance it did while it contained the insect. It is therefore ready for a cabinet, without any preparation whatever. But if the animal has not quitted its envelope, it will be necessary either to drop the Pupa into warm water, or to heat it in a tin case before the fire; the former mode, however, is the best, and least liable to change the colors of the Pupa.

METHOD OF BREEDING INSECTS.

BREEDING CAGES.--These must be made of oak, or other hard wood, as pine is apt to kill the Caterpillars, from its smell of turpentine. The most convenient size for a breeding cage is eight inches in breadth, four deep, and one foot in height. It is not proper to place within a cage more than one species of Caterpillar, as many of them prey upon each other. Indeed, animals of the same species will devour each other, if left without food. The Caterpillars of insects, for the most part, will only eat one particular kind of food, so that it is better to have no more than one sort in a cage.

There must be at the bottom of the cage earth to the depth of two inches; this should be mixed with some fine sand and vegetable earth, if possible, to prevent it from drying. The cages should be kept in a cool cellar or damp place, because many insects change into the Pupa condition under the earth; so that it would require to be somewhat moist, to prevent the destruction of the animal. The shell or case of the Pupa also becomes hard, if the earth is not kept moist; and, in that event, the animal will not have sufficient strength to break its case at the time it ought to emerge from its confinement, and must consequently die, which but too frequently happens from mismanagement.

Some seasons are more favorable than others for the production of Caterpillars, and to keep each kind by themselves would require an immense number of cages, as well as occupy much time in changing the food, and paying due attention to them. To obviate this, some persons having large breeding cages, with a variety of food in them, which must be cleaned out every two days, and fresh leaves given to the Caterpillars; as, on due attention to feeding, the beauty and vigor of the coming insects will much depend.

The Larvæ of insects, which feed beneath the surface of the earth, may be bred in the following manner: Let any box that is about three or four feet square, and two or three feet deep, be lined internally with tin, and a number of very minute holes be bored through the sides and bottom. Put into this box a quantity of earth, replete with such vegetables as the Caterpillars subsist on, and sink it into a bed of earth, so that the surface may be exposed to the different changes of the weather. The lid should be covered with brass or iron net-work, to prevent their escape, and for the free admission of air.

The young Entomologist should obtain a cabinet of about thirty drawers, arranged in two tiers, and covered in with folding doors. There is a great convenience in this size, as the cabinet is rendered more portable, and at the same time admits of having another of the same size, being placed above the top of it, as the collection increases, without injuring the uniformity, and thus the drawers may be augmented to any extent. It is immaterial whether the cabinet is made of mahogany or oak; sometimes they are constructed of cedar, but seldom of pine, or any other soft wood. Small cells must be made in the inside of the fronts for camphor.

CORKING OF DRAWERS.--The simplest way to get the cork is to purchase it of a cork-cutter, ready prepared, but it will be much cheaper for the Entomologist to prepare it himself. In this case, it should be cut into strips of about three inches wide, with a cork-cutter's knife, to smooth the surface and to divide it. The strips should be fixed in a vise, and cut to the thickness required with a fine saw; but grease must not be used in the operation, as it will not only prevent the cork from adhering to the bottom of the drawer, but will also grease the paper which should be pasted on its surface. The black surface of the cork should be rasped down to a smooth surface. After having reduced the slips to about three quarters of an inch in thickness, the darkest, or worst side of the slip should be glued down to a sheet of brown, or cartridge paper; this should be laid on a deal board, about three feet in length, and the width required for a drawer or box; a few fine nails, or brads, must be driven through each piece of cork to keep it firm and in its place until the glue be dried; by this means, sheets of cork may be formed the size of the drawer. All the irregularities are filed or rasped down quite to a level surface, and then polished smooth with pumice-stone. The sheet, thus formed and finished, is glued into the drawers. To prevent its warping, some weights must be equally distributed over the cork, that it may adhere firmly to the bottom of the drawer. When quite dry, the weights are removed, and the cork covered with fine white paper, but not very thick. The paper is allowed to be quite damp with the paste before it is placed on the cork, and, when dry, it will become perfectly tight.

Insect cabinets should be kept in a very dry situation, otherwise the antennæ, legs, etc., will become quite moldy. The same evil will ensue if the insect is not perfectly dry before it is placed in the cabinet. Should an insect be covered with mold, it can be washed off with a camel's-hair pencil, dipped in camphorated spirits of wine; in which case the insect must be dried in a warm airy situation before being placed in the cabinet.

There should always be plenty of camphor kept in the drawers, otherwise there is great danger to be apprehended from mites; where these exist, they are easily discovered by the dust which is under the insects by which they are infested. In which case they must be immediately taken out and rubbed clean with a fine camel's-hair pencil, and well imbued with the solution of corrosive sublimate, and then placed near a fire, taking care, however, that too great a heat is not applied, as it will utterly destroy the specimen. The Butterfly, Sphinx, and Moth tribes are extremely liable to the attack of mites, and should, therefore, be frequently examined.