Instructions for collecting and preserving various subjects of natural history; as animals, birds, reptiles, shells, corals, plants, &c. Together with A treatise on the management of insects in their several states; selected from the best authorities. By E. Donovan,:
Donovan, E. (Edward), 1768-1837.
Page  21

INSTRUCTIONS FOR COLLECTING INSECTS.

INSECTS are collected in every state, though in the Caterpillar, or Chrysalis, they are preferred, not only as the time of their ap∣pearance in the winged state may be then carefully attended to, but they will not be so liable to disfigure and damage their tender mark∣ings, as those which have been in the wind or rain; and if they are taken with care from the breeding-cage immediately after their wings have attained a proper size, they may be preserved free from any injury to those beautiful feathers, which are generally much discom∣posed in such Insects as are taken in flight.

There are some which cannot be found in the Caterpillar state; or if found, cannot be provided with food; those are generally of that kind which collectors term internal, or underground feeders, and either subsist on some substance unknown to us, or which we cannot raadily supply. The larvae of Beetles and many other kinds of Insects, are of this description: numbers of the Moth tribe have hitherto only been taken in the Fly state, and are supposed to feed Page  22in the night; they live in cells which they form in the earth, and come up in the evening to feed, but descend again into their cells before day-break; it is therefore that some Aurelians have sought for Caterpillars by the light of a candle or lanthorn, and have been very successful: the most valuable insects have been discovered by this means.

Insects are found in almost every situation, the summits of the loftiest trees, and the lowest herbage equally abound, and the gra∣dations between swarm with an infinity of species: the collector must be therefore supplied with a different apparatus, according to the state in which the Insects may be found; those in present use, though few and simple, require very little improvement, as they answer every necessary purpose. We shall enumerate the following articles, which are indispensibly useful to the collector,

  • A large Bat-fowling-net,
  • A pair of forceps,
  • A number of corked boxes of various sizes,
  • Ditto small pill boxes.
  • A spare box with c••••ps, and
  • A pincushion well stored with pins of different sizes.

PLATE II. FIG. 1. represents the Bat-fowling-net, fitted for use.

FIG. 2.

shews the frame, which is made entirely of cane, or of light wood, with a cane bow at the top; it should unskrew, or disjoint at a, a, a, for the convenience of being conveyed in the pocket.

Note, This frame should not be less than four or five feet in length, when fitted together.

Page  23The net is to be made of Scotch gause, not very fine, and bound entirely round with a broad welt, doubled to form a groove into which the sticks are to slip:—this bordering may be excepted at d d, but the gause at bottom must be turned up about six inches and form a bag; each stick or frame when the pieces are fitted together, is to pass into the groove at b b, slip up to c, and be there fastened by a piece of tape through a loop or hole; let the whole be drawn tight and each side at b b be tied to the nails; the handles are to be held one in each hand, when the net is used.

With this net it is intended to catch Moths on the wing, and that purpose it answers very effectually, as it may be instantly opened or folded together, and secure the Insect between; even Insects of the smallest kinds cannot escape, if the net is not damaged and the gause fine.

It also answers well for collecting Caterpillars.—Expand the net immediately under the bush, or branch you mean to examine, another person may beat or shake the bush with a stout stick, and not only a number of Caterpillars will fall down, but many of the minuter kinds of coleopterous, and other Insects also; Moths re∣main torpid and shelter in the bushes in the day time, and by beating are ery often taken, as they cannot readily fly away when they fall into the net.

PLATE 1. FIG. 3 and FIG. 4.

The forceps are about ten or twelve inches in length, are made of steel, and may be purchased at the hardware shops; their fans are made either of a triangular or hexangular form, and are covered with fine gause; they are held and moved as a pair of scissars, and where they can be conveniently used are to be preserred, as the Page  24Insect is more confined, and not so liable to rub off its down as when taken in a larger net. If an Insect is on a leaf, both leaf and Insect may be enclosed in the forceps; or if it be lodged against the trunk of a tree, paling, or any flat surface, you may very conve∣niently entrap it; when you have it between the gause, press with your thumb, (or thumb nail if the creature be small) on the thorax, rather smartly, but not so as to crush it; you may then shake it into your hand to set it, without any apprehension of its flying away: or you may put the pin through the thorax while the Insect is confined between the gause, open the forceps and take it carefully out by the pin.

Page  25

CATERPILLARS.

MOST Caterpillars lurk among the lowest herbage in the night time, begin to ascend early in the morning, and about noon are found feeding on the tops of their respective plants; they descend gradually as the sun declines, and at the close of the evening are again concealed in the low herbage: night feeders ascend in the evening, and descend as morning approaches.

To collect Caterpillars it is only necessary to expand the fowling∣net, or a large sheet, under the branches, then beat them with a stick or pole, and the Caterpillars will be shook down with the frag∣ments of the foliage and broken twigs.

When you have procured the Caterpillars, be particularly attentive to note the plant on which you found each species, and supply them plentifully with fresh food every day of that kind; only obser••f they are moulting they must not be disturbed, or the stale food be removed, but give a fresh supply when the creature has recovered its strength.

Insects in this state are rarely found on plants which do not afford nourishment to their species, but it sometimes unfortunately hap∣pens that stragglers are taken on some particular herbage, altogether of a different nature to its proper food; and indeed in some cases the most skilful practical emtymologists are deceived, the Caterpillar refuses to eat of the proffered plant, and dies. Some* will devour Page  26indiscriminately the leaves of almost every species of plants, and are therefore called general feeders; some are more limited in this particular, but feed on several kinds; others* are designed to eat the leaves of two or more plants, and a few subsist on one species only.

Neither can any certain criterion be formed as to the part of the plant, for though most Caterpillars devour the leaf, some subsist on the roots; others on the buds§, flowers, fruit, and indeed on every other part** of the plant, shrub or tree.

It is not always possible if one kind of food cannot be procured with convenience, to determine from the quality of that food, what other kind will best suit the creature; sometimes plants of the most opposite nature have nourished the same Caterpillar. The PHALAENA Antiqua has devoured leaves of the thorn, and of the rose; and has throve well when fed on the poisonous laurel, and the deadly nightshade.

They should always have an abundance of food, for some kinds devour a very considerable quantity in a few days: the PAPILIO Brassicoe, Cabbage Butterfly, eat in one day twice its own weight of food.

Page  27Doctor Lodovico Bellardi, a learned and ingenious Botanist of Turin, discovered, about six years ago, after a number of experi∣ments, a new method of feeding Silk-worms, when they are hatched before the mulberry-trees have produced leaves, or when it happens that the frost destroys the tender branches. Whether this discovery may be applied with equal propriety in other instances seems at present undertermined, though from some recent experi∣ments we are inclined to believe the possibility of feeding Caterpil∣lars in backward seasons in this manner; we have tried several Caterpillars which were nearly full fed on the leaves of thorns and oak so prepared, and have observed them to eat it when no other food was given, but cannot say how they may thrive if fed on that aliment alone. This new method consists in giving the Caterpillars the dried leaves of their usual food, powdered and moistened; and repeated experiments, says our author, prove that they (the Cater∣pillars of Silk-worms) prefer it to any other, and eat it with the greatest avidity. The leaves must be gathered about the end of au∣tumn, before the frost commences, in dry weather, and at times when the heat is greatest. They must be dried afterwards in the sun, by spreading them upon large cloths, and laid up in a dry place after they have been reduced to powder. When it is necessary to give this powder to the Caterpillars it should be gently moistened with a little water, and a thin coat must be placed round the young worms, which will immediately begin too feed upon it.

THE BREEDING CAGES

May be made of deal, in the form represented at FIG. 2, PLATE I. with a frame door covered with gause, or crape, to admit fresh air; and a hole in the bottom through which the Page  28stalks of the plants may be put into a phial of water to preserve them fresh.

Those cages should never contain more than one kind of Cater∣pillar, as some species devour others; and indeed, if left without food, will devour those of their own kind also.

"Let not the boxes which are taken in the pocket for Cater∣pillars, nor the cages made for breeding Insects be made of deal or fir, except they be well lined with paper; for the effluvia of the turpen∣tine, raised by the heat of the pocket, or that of the sun, is ex∣tremely prejudicial to them, and seldom fails to destroy the greatest part of the Caterpillars contained therein for any length of time. The cause of the deaths of the Caterpillars, found at the bottoms of cages or pocket boxes, is generally attributed to buises got in beat∣ing the trees for them at the time of collecting them, which is a great mistake, as those which happen to be injured in beating, seldom die till the time of changing their skins, or of their transfor∣mations, and will nevertheless eat heartily till either of these times approach. If the inside of the cages or boxes be well lined with paper, as aforesaid, and air-holes made in the sides and tops, cover∣ed with crape, canvas, &c. to admit air, it will in a very great measure prevent the above ill effects."—Harris.

Put a small quantity of moist earth, about an inch deep, at the bottom of every cage, but if the Caterpillars are large, more in pro∣portion; always allowing a sufficient quantity for them to bury in.

The cages must never be exposed to the scorching rays of the sun; on the contrary, place them in some cool shady situation.

Page  29And the Chrysalides should be preserved in some cold, or moist place, in the winter; for by being kept too dry the earth about them will absorb the nutritive moisture from the Animal, thereby not only weakening it, but hardening the shell, so that its strength will be insufficient to burst open the case when it should come forth; and thus enclosed it must perish miserably.

The larvae of many Insects that feed beneath the surface of the earth may be bred by the Aurelian in the following manner: let any box that is about three or four feet square, and two or three feet deep, be lined or covered externally with tin, and bore through the sides and bottom a number of very minute holes: put into this box a quantity of earth that is replete with such vegetables as you are certain 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, unless the sun is very hot, or the rain heavy; you may then put the Caterpillars into the box, and to prevent their escape, cover the opening with brass or iron net-work.

Page  30

PUPA.

WE have before observed, that Insects taken in this state are most likely to be perfect and vigorous, and are therefore more generally fought for by Aurelians than even when in the Caterpillar state. Some Chrysalides are buried in the earth; some penetrate into rotten wood; and some lie concealed underneath the bark of trees.

An instrument after the form of a hoe or trowel is used when you search for those of the first kind; and the only places worthy atten∣tion are at the roots of trees, as oaks, elms, &c. or beneath the un∣derwood: open the earth close to the tree and search to the depth of several inches.

Such as penetrate into wood, require more care lest they be de∣stroyed when the attempt is made to extricate them; sound on the bark with a stick and you will discover hollows where no external signs are visible; tear off the bark, and with a knife cut away the wood that surrounds the orifice of the cavity to enlarge it, and take out the Chrysalis as carefully as possible.

Whether found in the wood, or adhering to the inside of the bark, it should be preserved with the same substance in the breed∣ing boxes; and if found spun up on the branches of trees, or in the mould, manage to adjust them in a similar manner in the boxes. —They must be handled as little as possible, and be very careful Page  31not to press on any part; as the least rough treatment will either kill or cripple the Insect within.

Swammerdam used to hatch the eggs, feed the larvae, and pre∣serve the pupa of aquatic Insects, in a shallow dish, which he covered with white paper, occasionally moistened, and pierced in several parts for the admission of air.

Page  32

PERFECT STATE.

IT is in this state we find an immense quantity of Insects, of whose Larvae or Caterpillars we are altogether ignorant; and indeed such are the dispensations of Providence to this inferior rank in the scale of animated nature, that many are provided with the means of subsistence, in the most secret situations; they are hatched in the midst of plenty, and instinct prompts them not to remove from it; but when they are matured that same instinct bids them burst the shackles of their bondage.

Such as wish to collect, should pay a proper attention to the state of the weather; if it proves fine, and the sun emits much warmth, Insects are very brisk; but if a cold or windy day it will be only a fruitless toil to attempt collecting, as all Insects at such times shelter within the herbage, and instead of flying upward, as usual when disturbed, they dart into the thickest of the underwood; or if once they rise above the bushes, they are impetuously hurled by the current of the wind, far beyond the reach of the fowling-net.

"The Garden White is as good a token for fine weather as may be; when these flies are out in a morning, it seldom or ever hap∣pens but a fine day ensues. This fly is also called a Tally for the Swallowtail, which appears from the Chrysalis at the same time of the year."—Harris.

Page  33For the smaller kinds of lepidopterous Insects, before sun-rise or after sun-set; though many may be taken by beating the bushes in the day time.

Butterflies are abroad in the day time only; and the best time to collect Moths on the wing, is during the night, especially an hour or two after sun-set.

At day-break many Insects are on the wing; and most kinds are observed in hot weather to come forth after rain, to enjoy the humidity of the air, which is then damp but warm. This is the best time for collecting, as their wings are less liable to stiffen be∣fore they can be set.

The males of some, if not of every species of the Moth tribe, and perhaps of other Insects also, by a very astonishing faculty, are able to discover the females at a great distance, and in the most secret situations; this has been before noticed by Barbut, Harris, and others; and some collectors have endeavoured to find the male In∣sects by this means; they enclose the living female in a breeding-box, and place it as near the usual haunts of the species as convenient, the males will generally be observed soon after, fluttering on the box, and endeavouring to gain admission to the female. This experiment is generally practised with success on the Fox, and Egger, Moths.

Every species has a distinct time for its appearance, and this punctuality is scarcely forwarded or retarded a few days, except by the unusual mildness or inclemency of the season: if you discover a brood of Insects at a certain time of the year, precisely or nearly at the same period of the year following, you will find a brood of the same species; unless by accident they have been destroyed. It Page  34is true that some Insects are very variable in this particular*, and appear in one season but disappear the next; which however will not be observed with most kinds.

It is also to be remembered that certain spots of ground, or par∣ticular situations, should always be noticed; those are termed by collectors the haunts of Insects, and however unnecessary this may appear, experience will ensure, that some kinds are confined to one certain spot, and are not to be found in any other part of the same wood; so that having once discovered the haunt of an Insect, you may be able every season to take some of that species; or perhaps oftener, as some kinds have two or more broods every summer.

The sequestered vale, the hill, meadow, garden, and even dung∣heap, are the usual haunts of certain species; the PH. HUMULI has been called the Ghost, not only from its white colour, but as being generally sound in church-yards, where an abundance of burdock is permitted to grow; the PH. GROSSULARIATA, Large Magpie or Currant Moth, is mostly found in gardens; the PH. FESTUCAE invariably near marshes; the Heath Moth receives its English name from the situations it is always discovered in; and the species of Butterfly known to collectors by the name Chalk-Hill Blue, is taken on the chalky hills and pits leading to Darent Wood,Page  35a little distance beyond Dartford, Kent; the usual haunts of the Red Arches Moth, is among the oaks, &c. within the intricacies of the wood; but of the Scallop-Shell Moth, the skirts or lanes near; the Meadow Brown Butterfly, in meadows; the Gothic Moth, against banks; and most coleopterous Insects, or Beetles, in dung, &c.

Having now given an outline of all the rules which appear neces∣sary for the purpose of collecting Insects, we shall proceed to their preservation, which above all will act as a particular incitement to the early collector, who it is supposed would feel very little pleasure at the recollection that all the fruits of his toil in one season would be destroyed in the next; or at best that his specimens would only retain a wretched vestige of their original perfection.