_SETTING AND PRESERVING_
_Setting and Preserving Butterflies and Moths_
Up to the present we have been dealing only with living forms--learning
how to catch and rear the Lepidoptera that fall to our lot; but now we
have to become acquainted with the methods of preparing our dead
specimens in such a way that they may form a useful collection for
future study and reference. Our first attention shall be given to the
apparatus necessary for this work.
The most important requirement is the setting boards, of which several
are necessary, the sizes varying according to the dimensions of the
different insects to be 'set.' The _lengths_ of all the boards should be
the same, not only for the convenience of packing when not in use, but
also in order that they may, if required, be arranged neatly in the
'drying house' to be presently described. The widths only will vary, and
in this respect the boards must be adapted to the measurements of the
insects from tip to tip when the wings are fully expanded. Thus, a set
of a dozen boards, ten or twelve inches long, and from one to five
inches wide, will do for a good start. Of course you may commence with a
smaller number than twelve, but if you really mean to do the thing well,
you will eventually require a good stock of boards.
Here, again, it may be mentioned that all the necessary requisites may
be purchased ready for use, a set of boards and a drying house complete
costing from ten to twenty shillings according to size and quality; but
as the reader, like myself, may prefer to construct his own, I will
supply him with hints and suggestions sufficient for the work.
Each board is constructed in this way. Cut out and plane up a piece of
wood of the required length and breadth, and about one-eighth of an inch
thick. Glue on the top of this a layer of cork about half an inch in
thickness, leaving the whole under a moderate pressure until the glue is
quite hard. The sheets of cork for this purpose may be bought at any
naturalist's stores; but slices cut from good large bottle corks may be
made to answer equally well if you don't mind the extra time expended in
cutting and fixing.
When the glue has well set, trim off the edges of the cork flush with
the sides of the wood, and then cut out a groove down the whole length
of the cork, of course in the middle, and of such a size that it will
just contain the bodies of the insects for which it is intended.
[Illustration: FIG. 60.--SECTION OF A SETTING BOARD.]
The satisfactory cutting of this groove is not a very easy matter, but
if its position is first carefully marked, a long rat-tail file may be
made to plough it out neatly and regularly. As an alternative the
following plan is good. First cover the wood with a layer of cork about
a _quarter_ of an inch thick, and then glue on the top of this _two_
narrower strips, about as thick as the bodies of the insects for which
the board is intended, leaving a space of the required size between
them, as shown in fig. 60. In this way you get a groove of square
section, that is in some respects preferable to the round one cut out by
means of the rat-tail file.
[Illustration: FIG. 61.--SECTIONS OF SETTING BOARDS.]
Now comes a question about which there is a difference in the tastes or
fancies of entomologists. Shall the boards be perfectly flat on the top,
or shall the sides slope from the groove, or shall the surface be
rounded? A glance at the three sections of setting boards will show
clearly what is meant. The rounded board is most commonly used, and the
graceful curve thus given to a butterfly or moth set on such is
certainly attractive; but it is not natural. The wings of these insects
are rigid, and are never seen bent into such curves in a living
specimen. For this reason I much prefer a perfectly plane surface on
each side of the groove. Then, as to whether there shall be a slope or
not, this is a matter of less importance. A very decided sloping of the
wings is certainly not so convenient for future examination; nor does
it, to my mind, look nearly so well as both sides in the same plane, or
at a very gentle inclination. But perhaps this subject had better be
left to the taste of the reader, remembering, however, that, whatever
plan be adopted, all the boards should be alike in this respect, so that
there may be a degree of uniformity in the cabinet.
The surface of the cork must, in all cases, be nicely smoothed down with
glass paper, and then covered with thin white paper, fixed to its
surface with ordinary paste.
When insects are on the boards, they should be placed in an airy spot,
as free as possible from dust, while they are drying. Hence the
advisability of some form of 'drying house.' This is simply a box,
standing on end, and provided with a hinged door consisting of a sheet
of perforated zinc in a wooden frame. The boards may slide in this on
little slips of wood nailed or glued on to the sides, or the wooden
bases of the boards may project beyond the cork at the ends, and slide
into grooves in the side of the house.
[Illustration: FIG. 62.--A BUTTERFLY ON THE SETTING BOARD.]
Beyond these requirements nothing is wanted save a good stock of pins,
thin card or ordinary writing paper, and a 'setting needle.' The
last-named item is simply a needle mounted in a handle, and a good one
may be made by thrusting the head of a darning needle into a piece of
twig. The pins used for setting--that is, for fixing the pieces of paper
or card to keep the parts in position--may be of the ordinary kind; but
entomological pins are far preferable, even for this purpose; for, being
much thinner, they do not damage and disfigure the setting boards so
much.
Now as to the setting. First see that the pin with which you are to fix
your dead insect passes centrally through the thorax. Then fix it firmly
on the setting board, its body lying neatly in the groove of the cork.
Cut out some little pointed strips of card or paper, and, after bringing
the wings into position with the setting needle, fix each one by a
pinned strip. In spreading out the wings, care must be taken not to
pierce them at all, but simply to push them into their place by pressing
the needle at their bases, or by putting the needle beneath and
_lifting_ them out.
Instead of pointed pieces of card, uniform strips of paper may be used,
as shown in fig. 63, each strip passing over both wings.
After the four wings have been properly arranged, a few extra pins may
be used to keep other parts in position. Thus, the antennae may be placed
at equal angles, the proboscis may be extended, and a couple of pins may
be used to support the abdomen if it is inclined to bend downward.
[Illustration: FIG. 63.--ANOTHER METHOD OF SETTING BUTTERFLIES AND
MOTHS.]
As before mentioned, insects should be set soon after they are dead,
while the parts are still soft and supple. But where this cannot be
done, and the specimens have become stiff, brittle, and rigid, they must
be 'relaxed' before any attempt is made at setting them out.
This process of relaxing consists in placing the specimens in a very
moist atmosphere for a few days. There are several simple ways of doing
this, many of which will readily suggest themselves to the reader. Your
collecting box, if a zinc one, may also be used as a relaxer. Pin your
stiff insects in it, after well moistening the cork, and simply shut
them up for a day or two. Any metal box will serve the same purpose
providing you put into it a piece of sheet cork on which to fix the
insects, and this cork may rest on a bed of moist sand.
Another plan is to float the pinned specimens on corks in a shallow
vessel of water, and cover them over with a bell glass.
Insects that are being relaxed should be examined from time to time, and
the degree of flexibility acquired tested by a gentle pressure of the
setting needle or by blowing on them. If not sufficiently supple, give
another day in the damp cell, but never allow them to be forgotten till
they are covered with mildew.
The time occupied in thoroughly drying butterflies and moths will vary
considerably according to their sizes and the condition of the
atmosphere. In hot and dry summer weather four or five days will prove
quite sufficient for the _very_ small and thin-bodied species. From one
to two weeks, however, may be looked upon as the average period; but the
large and thick-bodied moths may require more than this.
Perhaps the best test of their condition is the gentle pressing of the
setting needle against the abdomen--the last part of the body to become
dry and stiff. If the abdomen seems quite firm and rigid, you are pretty
safe in removing the specimen from the board; but if it bends at all
under a slight pressure of the needle let it remain for a day or two
longer.
If your cabinet is quite ready for the reception of new-comers, the
insects may be put in their proper places immediately after their
removal from the setting boards; but if not, they may be pinned
temporarily in a 'store box' till the time comes when you have proper
accommodation provided. The full consideration of these matters will be
dealt with in another chapter.
It is possible that the setting of some of your specimens will not
exactly please you. If such is the case, put them in a relaxing box for
a day or two, and then reset them more to your fancy.
We have now to deal with a matter that applies more particularly to
moths, especially the very large and thick-bodied species. The abdomens
of these become more or less contracted and shrivelled on drying,
sometimes to such an extent as to look most unsightly.
There is a remedy for this, and the time and patience required in
working it out will be well repaid by the superior results obtained.
While the abdomen is still in a soft condition, make a slit throughout
its length with a very sharp knife or a sharp-pointed pair of scissors.
This slit should be made down the centre of the under surface, or, if
the insect is to be placed in the cabinet with the under side exposed,
down the middle line of the back. Then remove all the contents of the
abdomen, scraping them out with a piece of hooked wire, or removing them
with a fine pair of forceps, and leaving the skin as clean as possible
both within and without. Now introduce a packing of cotton wool, just
sufficient in quantity to maintain the natural form of the body as the
specimen dries.
There is another good method of stuffing moths that possesses a decided
advantage over the one just described, since it leaves the specimen in
such a perfect condition that it shows no appearance of having been
stuffed when viewed from either side. This consists in snipping off the
abdomen at the waist, clearing out the contents with a hooked wire,
lightly stuffing it with cotton wool pushed in at the waist, and then
setting it aside to dry, while the other part of the insect is
undergoing the same process on the setting board. When both parts of the
moth are thoroughly dry, the stuffed abdomen is easily fixed in its
place with a little coaguline; and this, if neatly done, will not show
the slightest sign of the treatment to which the insect has been
submitted.
Even after your insects are finally housed in the cabinet, they are
subject to two other dangers, both of which are more destructive to
moths than to butterflies. One is technically known as 'grease,' and the
other is the invasion of certain museum pests that feed on the
specimens, causing them to fall to pieces.
Examine the moths that have been for a time in the cabinet, and some are
sure to exhibit an oily or greasy appearance, the hairs of the abdomen,
and perhaps also of the thorax, being clogged together just as if the
specimen had been dipped in oil, the same miserable condition perhaps
being shared also by parts of the wings.
This is due to the gradual oozing out of the fatty matter that is always
present to a greater or less extent in the bodies of the insects, and
which must necessarily show itself more sparingly in specimens that have
been carefully stuffed.
The old saying, 'Prevention is better than cure,' applies well in the
present case; but as there are times when a knowledge of the 'cure' is
the only means of saving a valuable specimen from destruction, we will
study both.
To deal with the two in the order of the well-worn proverb, we will
consider the prevention first. Always carefully clean out and stuff the
abdomens of large-bodied insects; and as a rule, treat them with some
substance that will either absorb or dissolve out all oily matter. I
think the best plan is to remove the abdomen, clean it out if its size
permits of such an operation, and then, after labelling it to prevent
its future application to the wrong body, either let it remain in a
bottle of magnesia for several weeks, or soak it in benzole or ether for
a few hours or longer.
If magnesia has been employed as an absorbent, you have simply to blow
or lightly brush off the loose powder that clings to the body, and then
fix it in its place with coaguline. A body dipped in ether or benzole
will look as if completely spoilt at first, for the furry coat that
clothes it will lie matted and almost entirely robbed of its beautiful
colours, reminding one forcibly of the proverbial 'drowned rat.' But
take no notice of this change. Let the body have at least a few hours in
the liquid, extending the time to a day or two in the case of very large
ones and those which experience has proved to be particularly liable to
'grease;' and, immediately on withdrawing it, fix it with a pin in a
good strong draught, such as you may obtain by opening a window about an
inch, or, if a breezy day, in the open air.
These liquids are so volatile (and for that reason should never be left
exposed in an open vessel) that they rapidly evaporate, leaving the dry
hair to be loosened by the breeze, thus bringing back the natural
appearance almost perfectly.
It is probable that many of the smaller insects that were not considered
to require the stuffing or grease-removing operations will sooner or
later exhibit a greasy tendency in the cabinet. At first the abdomen is
affected, and the oily matter then gradually creeps over the rest of the
body, finally spreading over the wings, and giving the insect a most
deplorable aspect. But these are not irreparably lost, and the following
cure will often bring them back to their former beauty.
If the abdomen only shows signs of grease, cut it off and soak it in one
of the above-named liquids for a day or so, replacing it as above after
the drying operation. If, however, the oily matter has spread to the
thorax and the bases of the wings, the whole specimen must be soaked,
using a basin or jar of suitable size, covered with a plate of glass. A
good draught during the drying operation will do much to prevent the
hair from sticking in matted tufts close against the surface of the body
and wings, and a gentle brushing with a very soft camel-hair brush will
loosen and reset the fur.
The other danger to which we have referred is the invasion of certain
'mites' and other museum pests that pay periodical visits to our cabinet
drawers and store boxes, often committing such havoc as to severely try
the patience of an interested naturalist.
The way to prevent such intrusions is to make the atmosphere of the
compartments so obnoxious (to them) that they dare not enter; and,
further, to so spice up your specimens that they are no longer safely
edible to the invaders.
The first object can be attained by always keeping camphor or
naphthaline (albo-carbon) in each division. A lump of either substance
may be secured by pins or a little perforated cell in the corner of each
drawer or box, or the bottom of each may be dusted with finely powdered
naphthaline; but as both these solids are volatile, care must be taken
to renew the supply as occasion requires.
Then, with regard to the second precaution, perhaps nothing is more
effectual than corrosive sublimate. A little of this may be dissolved in
a small bottle of alcohol (spirits of wine), labelled with the name and
the word POISON, and kept ready for use. All the skins of stuffed
specimens should be painted with this solution, and the stuffing itself
may be moistened with it before insertion.
There is yet another circumstance that renders a watchful care of your
cabinet specimens necessary, if you happen to possess many that were
captured 'at sugar.' Some of these will have so gorged themselves with
syrup that they are literally full of it, and this will sometimes find
its way to the outside, often dropping on the surface beneath. In such
cases the sugar should be removed as completely as possible, and the
bodies stuffed, before they are quite dry; but if the specimens have
been in the cabinet so long that they are stiff and hard, the under
sides of the abdomens may be completely cut out with a very sharp knife
and thrown away, and then the sugar cleaned out from the upper shell as
neatly as possible.