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  42

LEPIDOPTEROUS INSECTS, AS BUTTERFLIES, HAWK-MOTHS, AND MOTHS.

IT is usual to put two specimens of each species of the Butterfly kind into the cabinet, one to display the upper, and the other the under side; for the under side is much more beautiful in most species, and differs entirely in appearance from the upper side.

Sphinxes and Moths are generally disposed in pairs to shew the male and female, and as their under sides are seldom very beautiful, only their upper sides are shewn.

Except a few species, Moths constantly conceal their under wings when at rest; but collectors sacrifice the propriety of their remain∣ing in a natural position, in order to display the under wings.—It is advisable to have one of every kind in a natural posture, as that will often essentially assist to determine the family of the Insect.

Provide a quantity of card braces, made in the same form as that represented at FIG. 8, PLATE II; and a board of a convenient Page  43size, covered with soft cork; it must be perfectly even on the sur∣face, and papered; this is termed the setting board.

For small Moths it is only necessary to put the pin through the thorax and they die in a very short time; but for larger kinds, the pin should be dipped in strong aqua fortis before it is put through the Insect.

It is very difficult to kill the largest kinds of Moths and Sphinxes:—select a large pin (comparatively for the size of the Insect) and dip it into aqua-fortis as before, but immediately that the pin is forced through the thorax withdraw it, and put a drop of aqua fortis into the wound; should this prove insufficient to kill it, put the point of the pin through a card, and hold it in the flame of a candle until it becomes red hot; this will kill the Insect immediately, and the card will protect it from being injured by the flame.

The Moth is then to be fixed on the setting board, and the braces are to be applied in the manner shewn at FIG. 9, PLATE II. The wings are to be carefully displayed by means of a large pin, and the braces put close down to prevent their return to the natural position.—Note, All Insects must be set while they remain limber, for if the parts stiffen they are apt to snap; they may be relaxed by floating them in a pan of water.

Insects should remain beneath the braces on the setting board until all the aqueous moisture be evaporated, or the wings will start from their position, and the bodies turn black, or mouldy; they should be placed in a dry situation, and be covered with gause for Page  44the admission of air for the space of a month at least, before they are put into the cabinet.

It is proper in this place to caution the young beginner not to at∣tempt to kill the Insects by fumigations of sulphur, &c. a practice too frequent with persons of this description, for should be by this means deprive the creature of its life, he will also deprive it of its beauty: It is even doubtful whether many may not survive the operation.

M. Lyonet placed several of the large Musk Beetles, probably the Cerambyx Moschatus, under a glass where he had been burning sul∣phur, and which he kept burning while they were there; and though the vapour was so thick that he could not discern them, and that he kept them therein more than half an hour, they did not seem in the least incommoded*.

Some Moths are very liable to change colour when placed in the cabinet, and particularly those which collectors term full-bodied; an oily matter is common to all Insects, but those are charged with a superabundance. It appears at first in spots on the body, but gradually pervades every part; in some it will even descend into the wings, and then an obliteration of all the tender marks and beautiful specklings is the least that may be expected, if a total change of its colours, to an uniform dirty brown, does not ensue. Hence it is that many of the Linnaean descriptions of In∣sects appear defective to such as breed them; we not unfrequent∣ly read, body black, though we know that part of the Insect is Page  45white in every specimen that is not greasy; the body of the Satin Moth* is perfectly white when fine, but after it has been killed some time, it becomes black in parts; the body of the Burnet Sphinx is of a very brilliant blue colour, with yellow bands on every annulation, when alive, but changes to a velvety black soon after the Insect dies; the same is observed on the body of the Currant Sphinx; and every part of the body of the Hornet Sphinx§ changes to a jet black, after being some time in the cabinet; although when alive it is a very bright yellow, with a band of purple. Hence also it is that some specimens of very common Insects are valuable, by having preserved their proper colours uninjured.

Various methods have been tried to extract the grease from the Moths, but a preventative should always be preferred.

If the grease has not spread into the wings, the Insect may some∣times be cured, but it will be very difficult, if not impossible, to eradicate the grease which has settled in patches on the wings.

Large Moths are to be opened in a strait line along the under side of the body, the entrails, &c. taken out, and the cavity filled with fine tow or cotton.—Note, This should be performed soon after the Insect is dead. The most delicate specimens may be preserved entire by this means; we have some very valuable Sphinges, Moths, &c. which were collected by an intelligent person in North America; they retain their colours to the utmost degree of perfection, and have only been prevented from changing black by this simple pre∣paration.

Page  46Sometimes it will be proper to break off the body close at the thorax, and substitute the body of another Insect which nearly re∣sembles it, and which is not so liable to change.

The method which is most successful for recovering the original appearance after the Insect has become greasy, is to powder some fine dry chalk, on a piece of heated iron; cover the chalk with a very fine linen cloth, and thereto apply the under part of the body of the In∣sect: the heat of the iron dissolves the grease, while the chalk ab∣sorbs it, and the linen cloth prevents the chalk from clotting to the Insect. This process may be repeated several times if the grease is not entirely eradicated by the first attempt. Always-observe to exactly attemperate the heat of the iron.

They may be baked in a slack oven, with the chalk placed to ab∣sorb the grease, without any considerable injury to the colours.

Some collectors open the bodies of large Moths, take out the en∣trails, and fill the cavity with fine dry powdered chalk.