and struggle violently, thus injuring its wings. It is well therefore
as soon as the insect has been captured to take hold of it at the
point where the wings join the body, while it is still in the net,
and by gently pinching the thorax to disable the insect. The fingers
are applied from the outside, as shown in the illustration (see Plate
D, Fig. 1). Then the collector, unstoppering his jar, inserts it into
the net and allows the butterfly to drop into the jar. Butterflies
belonging to the family of the _Hesperiidæ_, or “skippers,” are best
captured in the net by holding up the end of the bag. The insects will
then fly upward and settle near the top of the bag. The collector puts
the open jar with his right hand into the ring of the net and holding
the bag with the left hand brings the jar under the butterfly, and then
claps his left hand over the mouth of the jar, thus securing the insect
in the jar, where after a couple of seconds it will be stunned by the
fumes and fall to the bottom. Death is speedy, but not instantaneous,
and the insect should be allowed to remain a little while in the jar.
Having been asphyxiated by the fumes of the jar, the insect may then be
removed and either mounted upon a pin and transferred to a collecting
box, which will presently be described, or put into an envelope. It
is well not to accumulate too many insects in the collecting jar, as
those which are caught later will injure in their struggles those
which have been caught first. I make it a rule to rapidly transfer the
insects from the collecting jars to the collecting boxes which I carry
with me. The preservation of specimens in perfect freshness, without
torn or ragged wings, is of the utmost importance, and it is better to
take fewer specimens, preserving them in immaculate condition, than
to accumulate a quantity of ragged and battered examples. The old
adage, “Practice makes perfect,” applies in the use of the net and the
poisoning jar. There will necessarily be some failures on the part
of the young collector at the outset, but if he is neat and quick of
finger he will soon acquire the art of taking and preserving perfect
specimens.
The field box should be made of tin and should have a sheet of cork
securely fastened at the bottom. In one corner of the box, tied in
gauze and securely fixed in place, there should be a few lumps of
cyanide. Into this box the specimens should be pinned as they are
taken from the collecting jar, and the lid of this box should be kept
tightly closed most of the time, being opened only when the transfer of
the pinned specimens to the interior of the box is ready to be made.
Inasmuch as pinning insects on the field is not always satisfactorily
accomplished, the writer prefers not to pin them, but to carry with
him a supply of small pay-roll envelopes, into which the insects
are put, and these envelopes are then put into a box which has some
cyanide secured in it, as has already been described. The writer also
carries with him a little phial of chloroform in his vest pocket,
and he sometimes uses this to stun insects or puts a few drops into
the collecting box and then closes it. The objection to the use of
chloroform is that it induces spasms of the thoracic muscles, and
butterflies killed by the use of chloroform are not nearly so easily
mounted as specimens which have been killed with cyanide. Beetles,
wasps, and other hard-bodied insects should not be put into the same
collecting jars as those which are used for butterflies, as they are
very apt to injure the latter, tearing and spoiling the wings. If the
collector is engaged in taking other insects besides butterflies and
moths, he should have special jars in which to put the beetles and
other hard-bodied and spiny things.
If the collector does not wish immediately to mount his specimens, but
to preserve them for mounting at a future time, they may be left in the
envelopes of which I have spoken, or may be “papered.” The simplest way
of putting up butterflies in papers is to take an oblong piece of any
kind of moderately good paper and fold it as indicated in the diagram
(see Plate E, Fig. _b_), first folding on the line a-b, then on a-d
and c-b; then on the lines b-f and e-a, as marked in the diagram. The
result is the enclosure of the insect as shown in Plate E, Fig. _c_.
A hundred or more of such envelopes may be put into an ordinary cigar
box. Such boxes, filled with butterflies, in order to prevent mould and
the ravages of pests, should have some chloroform or carbon bisulphide
put into them and afterward a spoonful or two of naphthaline crystals.
Then they should be closed and sealed up by pasting strips of paper
over the edges. Butterflies thus collected on journeys may be safely
carried for long distances without injury, or even transmitted through
the mails provided the boxes are strong enough to resist crushing. When
on journeys the writer of these paragraphs always papers his specimens,
bringing them home to be later carefully mounted at his leisure. It
is of the utmost importance to note on each envelope the place and
the date of capture, so that these may later be placed upon the little
labels or tickets which are put upon the pins after the insects have
been expanded and mounted for display.
MOUNTING BUTTERFLIES
The writer cannot do better in dealing with this subject than to
transfer from “The Butterfly Book” the substance of the directions
there given in relation to this matter.
* * * * *
When the collector has time enough at his disposal he should at once
mount his specimens as they are intended to be displayed. The insect
should first of all be pinned. For this purpose “insect pins” should be
used. These are made either of soft steel or of pin metal. The first
are to be preferred, except in very damp climates, where they sometimes
rust if they have not been properly enamelled with shellac. The pin
should be thrust perpendicularly through the thorax, midway between the
wings, and at a considerable elevation upon the pin. It should then
be placed upon the setting board or setting block. Setting boards or
setting blocks are pieces of wood having a groove on the upper surface
of sufficient depth to accommodate the body of the insect and to permit
the wings to be brought to the level of the upper surface of the
board (see Plate D, Figs. 6 and 7; and Plate E, Figs. _d_, _e_, _f_).
They should also be provided either with a cleft or a hole which will
permit the pin to be thrust down below the body of the insect for a
considerable distance. As a rule the wings of all specimens should be
mounted at a uniform elevation of about seven eighths of an inch above
the point of the pin. This is known as the “continental method” of
mounting, and is infinitely preferable to the old-fashioned “English
method,” in which the insect was pinned low down upon the pin, so that
its wings touched the surface of the box.
EXPLANATION OF PLATE E
Fig. a. Vivarium, or cage in which to breed caterpillars.
_a_, base, kept even by cleats, _g_, _g_; on this is placed a pan 4
inches deep made of sheet zinc, and filled with earth; to the middle
is soldered a tube of zinc, into which a large bottle fits; the
bottle is filled with water to keep the plants placed in it fresh and
green; _b_, outer case, with sides of glass, fitting closely about
the zinc pan; _c_, top, covered with wire-cloth, rabbeted on _b_, and
easily lifted off.
Fig. b. Diagram showing way to make paper envelopes for butterflies.
Fig. c. Envelope folded with butterfly inside.
Fig. d. Stretching board for expanding moths and butterflies. Strips
of tracing-muslin are used on this to keep the wings down, paper will
also serve the purpose.
Fig. e. Stretching board, showing how wings may be held in place by
pieces of thin cardboard.
Fig. f. Showing the way in which the antennæ and body may be held in
place with insect pins while the insect is drying.
[Illustration: PLATE E]
Setting blocks are most advantageously employed in mounting small
species, especially the Hesperiidæ, the wings of which are apt to be
refractory. When the insect has been pinned upon the setting board or
setting block, the next step is to set the wings in the position which
they are to maintain when the specimen is thoroughly dry. This is
accomplished by means of what are known as “setting needles.” Setting
needles may be easily made by simply sticking ordinary needles into
wooden matches from which the tips have been removed; steel insect pins
will serve as well. In drawing the wings into position, care should be
taken to plant the setting needle or pin behind the strong nervure on
the costal margin of the wing; otherwise the wings are liable to be
torn and disfigured. The rule in setting lepidoptera is to draw the
anterior wing forward in such a manner that the hind margin of this
wing is at right angles to the axis of the body, the axis of the body
being a line drawn through the head to the extremity of the abdomen.
The hind wing should then be moved forward, its anterior margin lying
under the opposing margin of the front wing. When the wings have thus
been adjusted into the position which they are to occupy, slips of
tracing-muslin or of paper should be drawn over them and securely
pinned, the setting needles being removed.
In pinning down the strips which are to hold the wings in place, be
careful to pin around the wing, but never if possible through it.
When the wings have been adjusted in the position in which they are
to remain, the antennæ should be attended to and drawn forward on the
same plane as the wings, and secured in place. This may ordinarily be
done by setting pins in such a position as to hold them where they are
to stay. Then the body, if it has a tendency to sag down at the end of
the abdomen, should be raised. This may also be accomplished by means
of pins thrust beneath on either side. Plate E, Fig. _e_, shows clearly
what is intended. When the insect has been set, the board should be put
aside in a place where it will not be molested or attacked by pests,
and the specimens upon it allowed to dry. A box with shelves in it is
often used for this purpose. This box should have a door at the front
covered with wire gauze, and the back should also be open, covered
with gauze, so as to allow a free circulation of air. A few balls of
naphthaline placed in it will tend to keep away mites and other pests.
The time which the specimen should remain on the board varies with its
size and the condition of the atmosphere. Most butterflies and moths
in dry weather will be sufficiently dried to permit of their removal
from the setting boards in a week; but large, stout-bodied moths may
require as much as two weeks, or even more time, before they are
dry enough to be taken off the boards. The process of drying may be
hastened by placing the boards in an oven, but the temperature of the
oven must be quite low. If too much heat is applied great injury is
sure to result. Only a careful and expert operator should resort to the
use of the oven, a temperature above 120 F. being sure to work mischief.
When butterflies or moths have been put up in papers or mounted on
pins without having their wings expanded and set, it becomes necessary
before setting them to relax them. This may be accomplished in several
ways. If the specimens have been pinned it is best to place them on
pieces of sheet-cork on a tray of sand which has been thoroughly
moistened and treated with a good dose of carbolic acid. Over all a
bell glass is put. A tight tin box will serve the same purpose, but a
broad sheet of bibulous paper should always be put over the box, under
the lid before closing it, and in such a way as to leave the edges
of the paper projecting around the edges of the lid. This is done to
absorb the moisture which might settle by condensation upon the lid
and drop upon the specimens. In a bell glass the moisture generally
trickles down the sides. Earthenware crocks with closely fitting lids
are even better than tin boxes, but they must have paper put over them
before closing, in the same way as is done when tin boxes are used.
When specimens have been preserved in papers or envelopes these should
be opened a little and laid upon damp, carbolized sand under a bell
glass or in a closed receptacle of some kind. Papered specimens may
also be placed in their envelopes between clean towels, which have been
moistened in water to which a little carbolic acid has been added.
The towels should be wrung out quite dry before using them. Pieces of
dampened blotting paper are even better than towels. The method of
placing between towels should never be used in the case of very small
and delicate species and those which are blue or green in color. Great
care must be exercised not to allow the insects to become soaked or
unduly wet. This ruins them. They should, however, be damp enough to
allow the wings and other organs to be freely moved. When the insects
have been relaxed they may be pinned and expanded on setting boards
like freshly caught specimens. It is well in setting the wings of
relaxed specimens, after having thrust the pin through the body, to
take a small forceps and seizing the wings just where they join the
body gently move them so as to open them and make their movement easy
before pinning them upon the setting board. The skilful manipulator in
this way quickly ascertains whether they have been sufficiently relaxed
to admit of their being readily set. If discovered to be too stiff and
liable to break they must be still further relaxed. Dried specimens
which have been relaxed and then mounted generally require only a short
time to dry again, and need rarely be kept more than twenty-four hours
upon the setting boards.
The process of setting insects upon setting blocks is exactly the
same as when setting boards are used, with the simple difference that
instead of pinning strips of paper or tracing-muslin over the wings,
the wings are held in place by threads or very narrow tapes, which are
wound around the block (see Plate D, Figs 6 and 7). When the wings
are not covered with a very deep and velvety covering of scales the
threads or tapes may be used alone; but when the wings are thus clothed
it becomes necessary to put bits of paper or cardboard over the wings
before wrapping with the threads. Unless this is done the marks of the
threads will be left upon the wings. Some little skill, which is easily
acquired by practice, is necessary in order to employ setting blocks
to advantage, but in the case of small species and species which have
refractory wings they are much to be preferred to the boards.
The work of mounting small insects which have been relaxed must be
done quite quickly and in a cool room or in a moist atmosphere. In a
very dry and hot atmosphere the minuter things dry so quickly that
difficulties are at once encountered.
* * * * *
One of the best ways in which to secure perfect specimens is to breed
them from the caterpillar, or even from the egg. A stylish and very
good cage for breeding is shown on Plate E, Fig. 2. As good a cage
as this is not necessary, and the collector will succeed with one or
more clean store-boxes covered with a lid consisting of a frame over
which gauze or muslin has been stretched. The food-plant on which the
caterpillar feeds is kept fresh in bottles or jars. It is important,
after the plants have been put into the jar of water, to stuff around
the stems cotton or soft paper, so that the caterpillars may not crawl
down and, falling into the water, drown themselves. The bottom of the
box may be filled to the depth of four or five inches with loam and
covered with dead forest leaves. The loam should not be allowed to
dry out thoroughly, but should be kept somewhat moist, _not wet_. A
little sprinkling of water from time to time will suffice when done
with care. The caterpillars feed upon the food-plant, and finally
undergo transformation in the cage into the pupa, and eventually
emerge as the butterfly or moth. The breeding of lepidoptera in this
way is a fascinating occupation for those who have leisure to attend
to it. For more minute instructions in reference to this matter the
reader is referred to “The Butterfly Book.” The caterpillars and
chrysalids themselves may be preserved in little phials, in alcohol
or in a solution of formaldehyde. The latter, however, is not to
be recommended, because, although it preserves colors better than
alcohol, and does not tend to shrivel up the bodies, it makes them
stiff and difficult to handle and examine. The best way of preserving
caterpillars is to inflate them. Directions for doing this are
contained in “The Butterfly Book.”
THE PRESERVATION AND ARRANGEMENT OF COLLECTIONS
In order to preserve collections of lepidoptera in beautiful condition,
light, moisture, and insect pests must be excluded. Light bleaches
many species, especially those which are red, brown, or green in
color. Moisture produces mold and mildew. Insect pests such as mites,
_Anthrenus_, and _Dermestes_, the two latter being species of beetles,
devour specimens. The receptacles containing collections should
therefore be furnished with covers excluding the light, kept in a dry
place, and be so tight that insect pests will not enter. However, as
an additional precaution, it is well to place in every box or drawer
moth balls or lumps of camphor, secured so that they cannot roll about.
These tend to deter predaceous insects from entering the receptacles.
If by any chance they have entered, neither the naphthaline nor
the camphor in some cases will prevent their ravages. In the great
collections which are under the care of the writer it is a rule from
time to time to go over all the cases and put into every receptacle a
small quantity of carbon bisulphide. The fumes of carbon bisulphide
kill all grubs and matured insects which may have hidden themselves in
the cases, and it is believed that it also tends to destroy the life
in eggs which may have been laid in the boxes. Great care should be
used, however, in employing carbon bisulphide, as the fumes mingled
with the oxygen of the atmosphere form an explosive compound. The work
should never be done where there is danger of ignition from an open
fire or light. Boxes for the preservation of insect collections are
made by many firms, and prices for such receptacles vary according
to their size and the materials employed in their construction. All
receptacles, however, should be lined at the bottom with cork or some
other soft material into which the pins sustaining the insects can be
put. We employ in the Carnegie Museum a composition cork covered with
white paper, which is made in sheets of varying sizes, according to
requirement, by the Armstrong Cork Manufacturing Company of Pittsburgh,
Pa., the largest cork-manufacturing establishment in the world. This is
the most satisfactory material which is made.
Large collections are advantageously preserved in cabinets, the drawers
of which are covered with glass through which the insects may be
inspected without handling them. Here again, for the details of the
construction of boxes, trays, and cabinets, the reader is referred to
“The Butterfly Book,” which may be found in every public library, and
is in the hands of multitudes of individuals.
In arranging specimens the scientific order should be followed. The
species belonging to a given genus should be placed together. The
little labels attached to the pins should give both the generic and the
specific name, the locality where the specimen was taken, and the sex,
if known. For the purpose of designating the sex naturalists employ
what are known as “sex marks,” the male being indicated by the sign of
Mars, ♂, while the female is indicated by the sign of Venus, ♀. The
inscription _Papilio philenor_, ♀, means that the specimen is a male,
and the inscription _Papilio philenor_, ♀, means that it is a female of
the same species.
The classification of the genera and species should be subordinated
further to the classification into families. There are five families of
butterflies represented in the United States and Canada. They are the
following:
1. The Nymphalidæ, or “Brush-footed Butterflies.”
2. The Erycinidæ, or “Metal-marks.”
3. The Lycænidæ, or “Blues,” “Coppers,” and “Hair-streaks.”
4. The Papilionidæ, or the “Swallowtails” and their allies.
5. The Hesperiidæ, or the “Skippers.”
In every well-arranged collection of butterflies certain
drawers or boxes should be set apart for the reception of the insects
belonging to these families, and they should be placed under their
proper genera, according to their species. Nothing is more beautiful
or interesting to those who have a love of nature than a collection of
butterflies thus classified and displayed.
In recent years an ingenious friend of mine has devised a system of
mounting butterflies under glass in cases made of a shell of plaster of
paris, which he backs with cardboard and seals around the edges with
gummed paper. Latterly he has taken to mounting them between pieces of
glass which he secures in the same way. Specimens thus preserved keep
well, may be handled readily without fear of injury to them, and in the
glass cases both sides of their wings may be examined. A collection
of butterflies mounted in this way may be stored in shallow trays and
placed in scientific order. The process of mounting in this fashion is,
however, somewhat laborious and expensive, and is not generally adopted
by scientific men, who wish to be free to examine their specimens under
the magnifying glass, occasionally touching the wings with benzine to
disclose the facts of neuration, and to minutely investigate the feet
and other parts of the body, which, when sealed up in the way I have
described, are not easily accessible.
* * * * *
Having thus briefly outlined the principal facts as to the nature
of butterflies in general, and the best methods of collecting and
preserving them, we now pass on to the description of the commoner
species which are found on the continent of North America, north of
Mexico and the Straits of Florida.
Class INSECTA (Insects)
Order LEPIDOPTERA (Scale-winged Insects)
Suborder RHOPALOCERA (Butterflies)
Family NYMPHALIDÆ (The Brush-footed Butterflies)
The Nymphalidæ may be distinguished from all other butterflies by the
fact that _in both sexes the foremost, or prothoracic, pair of legs is
greatly dwarfed, useless for walking, and therefore carried folded
up against the breast_. This is the largest of all the families of
butterflies and has been subdivided into many subfamilies. Some of the
genera are composed of small species, but most of them are made up of
large or medium-sized forms. To this family belong many of the most
gorgeously colored butterflies of the tropics, among them the brilliant
blue _Morphos_ of equatorial America.
The caterpillars, when they emerge from the egg, have heads much
greater in diameter than the rest of their bodies. In the earlier
stages the bodies taper from before backward, and are adorned with
little wart-like protuberances, which bear hairs. In later stages these
little protuberances in many genera are replaced by branching spines
and fleshy projections, which impart to the caterpillars a forbidding
appearance. The mature caterpillar generally has a cylindrical body,
but in the subfamilies, _Satyrinæ_ and _Morphinæ_, the larvæ are
thicker at the middle, tapering forward and backward.
The chrysalids, which are generally marked by metallic spots, always
hang suspended by the tail, except in the case of a few arctic species,
which are found under a frail covering composed of strands of silk
woven about the roots of tufts of grass, under which the larva takes
shelter at the time of pupation.
In the region with which this booklet deals all the butterflies
belonging to the _Nymphalidæ_ fall naturally into one or the other of
the following subfamilies: (1) the _Euplœinæ_, or Euplœids; (2) the
_Ithomiinæ_, the Ithomiids; (3) the _Heliconiinæ_, the Heliconians; (4)
the _Nymphalinæ_, the Nymphs; (5) the _Satyrinæ_, the Satyrs; (6) the
_Libytheinæ_, the Snout-butterflies.
KEY TO THE SUBFAMILIES OF THE NYMPHALIDÆ OF TEMPERATE NORTH AMERICA