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 paste-board 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, as in figure 26, 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, as at figure 24; the oblique cross-piece at the point should be of cane, and fitted into the angular ferrule; 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 ferrule 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, figure 31, must have a welting all around it, doubled so as to form a groove for the reception of the rods. ln 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 larvae 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, Figure 26. 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 Phial, Figure 33. 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, Figure 28. 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, Figure 29. 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. Figure 30 is a straight needle which is used for extending the parts of insects; at one end of the handle is the needle, and at the other a camel-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 antennas and palpi of insects of the minute kinds.
Brass Pliers, Figure 25. These are used for picking up small insects from the roots of grass, etc. They may also be used for laying hold of small insects, while they are yet free and not set up.
Fan Forceps. This very useful instrument to the entomologist, must be made of steel or iron, and about eight or ten inches in length; its general construction is like that of a pair of scissors, and it is held and used in the same manner. Towards the points are formed a pair of fans, which may either be square, oval, hexagonal, or octagonal in the edges, and the centers covered with fine gauze. The general size of the fans is from four to six inches. These are used for capturing bees, wasps, and muscae. They are also used for catching butterflies, moths, and sphinges. If an insect is on a leaf, both leaf and insect may be inclosed within the fans; or if they are on a wall or the trunk of a tree, they may be very easily secured by them.
If a butterfly, sphinx, or moth, are captured by the forceps, while yet between the fans, they should be pressed pretty smoothly with the thumb-nail, on the thorax or body, taking care, however, not to crush it. It may then be taken into the hand, and a pin passed through the thorax, and then stuck into the bottom of your hunting-box.
Quills. These are of great use in carrying minute insects. They should be neatly stopped with cork and cement at one end, the other end should be provided with a small movable cork for a stopper. Each end should be wrapped carefully round with a silk thread waxed, to prevent them from splitting.
Pocket Larvae-Box. For collecting caterpillars, this box is very essential: it consists merely of a chip-box, with a hole pierced in the center of the top and bottom, and covered with gauze, for the admission of air. It will be necessary to put into the box some of the leaves on which the larvae feed, as they are very voracious, and cannot long exist without food.
Pill-Boxes. No entomologist should be without five or six dozen of these useful articles. They are of great value in collecting the smaller species of lepidopterous insects, such as the tinea, etc., and only one specimen should be put in each box, as, if more than one, they are apt to injure each other's wings by beating against each other.
Setting Boards. These must be made of deal board, from a foot to 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 the form exhibited, Fig. 36, attached to the butterfly and other insects; and also at Fig. 39. They are pinned down on the insects, to keep their wings, etc., in a proper state, till they acquire a set.