Guide to the study of insects, and a treatise on those injurious and beneficial to crops: for the use of colleges, farm-schools, and agriculturists online

thorax of most insects. The Coleoptera, however, should be
pinned through the right wing-cover; many Hemiptera are
best pinned through the scutelluni. The specimens should all
be pinned at an equal height, so that about one-fourth of the
pin should project above the insect.

The best pins are those made in Berlin by Klager. They are
of five sizes, No. 1 being the smallest; Nos. 1, 2, and 5 are
the most convenient. For very minute insects still smaller pins
are made. A very good but too short pin is made by Edles-
ton and Williams, Crown Court, Cheapside, London. Their
Nos. 19 and 20 may be used to impale minute insects upon,
and then stuck through a bit of cork, or pith, through which a
No. 5 Klager pin may be thrust. Then the insect is kept out
of the reach of devouring insects. Still smaller pins are made
by cutting off bits of very fine silvered wire at the right length,
which may be thrust by the forceps into a piece of pith, after
the insects have been impaled upon them.



COLLECTING AND PRESERVING INSECTS. 89

Small insects, especially beetles, may be mounted on cards
or pieces of mica through which the pin may be thrust. The
French use small oblong bits of mica, with the posterior half
covered with green paper on which the number may be placed.
The insect may be gummed on the clear part, the two sexes to-
gether. The under side can be seen through the thin mica.

Others prefer triangular pieces of card, across the end of
which the insect may be gummed, so that nearly the whole un-
der side is visible.

Mr. Wollaston advocates gumming small Coleoptera upon
can Is. Instead of cutting the pieces of cards first, he gums them
promiscuously upon a sheet of card-board. "Having gummed
thickly a space on your card-board equal to, at least, the entire
specimen when expanded, place the beetle upon it, drag out
the limbs with a pin, and, leaving it to diy, go on with the
next one that presents itself. As the card has to be cut after-
wards around your insect (so as to suit it), there is no advan-
tage in gumming it precisely straight upon your frame, though
it is true that a certain amount of care in this respect lessens
your after labor of cutting-off very materially. When your
frame has been filled, and you are desirous of separating the
species, cut out the insect with finely pointed scissors."

For mending broken insects, i. e. gumming on legs and an-
tennae which have fallen off, inspissated ox-gall, softened with a
little water, is the best gum.

For gumming insects upon cards Mr. Wollaston recommends
a gum "composed of three parts of tragacanth to one of
Arabic, both in powder ; to be mixed in water containing a grain
of corrosive sublimate, without which it will not keep, until
of a consistency just thick enough to run. As this gum is of
an extremely absorbent nature, nearly a fortnight is required
before it can be properly made. The best plan is to keep add-
ing a little w r ater (and stirring it) every few days until it is
of the proper consistency. It is advisable to dissolve the grain
of corrosive sublimate in the water which is poured first upon
the gum."

Preservative Fluids. The best for common use is alco-
hol, diluted with a little water ; or whiskey, as alcohol of full
strength is too strong for caterpillars, etc., since it shrivels them



90 THE CLASS OF INSECTS.

up. Glycerine is excellent for preserving the colors of cater-
pillars, though the internal parts decay somewhat, and the
specimen is apt to fall to pieces on being roughly handled.

Laboulbene recommends for the preservation of insects in a
fresh state plunging them in a preservative fluid consisting
of alcohol with an excess of arsenic acid in fragments, or the
common white arsenic of commerce. A pint and a half of al-
cohol will take about fourteen grains (troy) of arsenic. The
living insect, put into this preparation, absorbs about y^g- of its
own weight. When soaked in this liquor and dried, it will be
safe from the ravages of Moths, Anthrenus, or Dermestes. This
liquid w r ill not change the colors of blue, green, or red beetles
if dried after soaking from twelve to twenty-four hours. He-
miptera and Orthoptera can be treated in the same way.

A stay of a month in this arseniated alcohol mineralizes the
insect, so that it appears very hard, and, after drying, becomes
glazed with a white deposit which can, however, be washed off
with alcohol. In this state the specimens become too hard for
dissection and study, but will do for cabinet specimens designed
for permanent exhibition.

Another preparation recommended by Laboulbene is alcohol
containing a variable quantity of corrosive sublimate, but the
latter has to be weighed, as the alcohol evaporates easily, the
liquor becoming stronger as it gets older. The strongest solu-
tion is one part of corrosive sublimate to one hundred of alco-
hol ; the weakest and best is one-tenth of a part of corrosive
sublimate to one hundred parts of alcohol. Insects need not re-
main in this solution more than tw r o hours before drying. Both
of these preparations are very poisonous and should be handled
with care. The last-named solution preserves specimens from
mould, which will attack pinned insects during damp summers.

A very strong brine will preserve insects until a better liquor
can be procured. Professor A. E. Verrill recommends two sim-
ple and cheap solutions for preserving, among other specimens,
the Iarva3 of insects "with their natural color and form remark-
ably perfect." The first consists of two and a half pounds of
common salt and four ounces of nitre dissolved in a gallon of
water, and filtered. Specimens should be prepared for perma-
nent preservation in this solution by being previously immersed



COLLECTING AND PRESERVING INSECTS. ' 01

in a solution consisting of a quart of the first solution ;i:id
two ounces of arseniate of potash and a gallon of water. (Pro-
ceedings Boston Society Nat. Hist., vol. x, p. 257.)

The nests, cocoons, and chrysalids of insects may l>e pre-
served from injury from other insects by being soaked in the
arseniated alcohol, or dipped into benzine, or a solution of car-
bolic acid or creosote.

Preparing Insects for the Cabinet. Dried insects may be
moistened by laying them for twelve or twenty-four hours in
a box containing a layer of wet sand, covered with one thick-
ness of soft paper. Their wings can then be easily spread.
Setting-boards for spreading the wings of insects may be made
by sawing deep grooves in a thick board, and placing a strip
of pith or cork at the bottom. The groove may be deep enough
to allow a quarter of the length of the pin to project above the
insect. The setting-board usually consists of thin parallel
strips of board, leaving a groove between them wide enough to
receive the body of the insect, at the bottom of which a strip
of cork or pith should be glued. The ends of the strips should
be nailed on to a stouter strip of wood, raising the surface of
the setting-board an inch and a half so that the pins can stick
through without touching. Several setting-boards can be made
to form shelves in a frame covered with wire gauze, so that
the specimens may be preserved from dust and destructive in-
sects, while the air may at the same time have constant access
to them. The surface of the board should incline a little to-
wards the groove for the reception of the insect, as the wings
often gather a little moisture, relax and fall down after the
insect is dried. Moths of medium size should remain two or
three days on the setting-board, while the larger thick-bodied
Sphinges and Bombycidce require a week to dry. The wings
can be arranged by means of a needle stuck into a handle
of wood. They should be set horizontally, and the front mar-
gin of the fore-wings drawn a little forward of a line perpen-
dicular to the body, so as to free the inner margin of the hind
wings from the body, that their form may be distinctly seen.
"When thus arranged, they can be confined by pieces of card
pinned to the board as indicated in figure 71, or, as we prefer,
by square pieces of glass laid upon them.




92 THE CLASS OF IXSECTS.

After the insects have been thoroughly dried they should not
be placed in the cabinet until after having been in quarantine
to see that no eggs of Dermestes or
Anthrenus, etc., have been deposited
on them.

For preserving dried insects in the
cabinet Laboulbene recommends plac-
ing a rare insect (if a beetle or any
Fig. 71. other hard insect) in water for an hour

until the tissues be softened. If soiled, an insect can be
cleansed under water with a fine hair-pencil, then submit it to
a bath of arseniated alcohol, or, better, alcohol with corrosive
sublimate. If the insect becomes prune-colored, it should be
washed in pure alcohol several times. This method will do
for the rarest insects ; the more common ones can be softened
on wet sand, and then the immersion in the arseniated alcohol
suffices. After an immersion of an hour or a quarter of an
hour, according to the size of the insect, the pin is not affected
by the corrosive sublimate, but it is better to unpin the insect
previous to immersion, and then pin it when almost dry.

For cleaning insects ether or benzine are excellent, applied
with a hair-pencil ; though care should be taken in using these
substances which are very inflammable.

After the specimens are placed in the cabinet, they should be
farther protected from destructive insects by placing in the
drawers or boxes pieces of camphor wrapped in paper perfo-
rated by pin-holes, or bottles containing sponges saturated with
benzine. The collection should be carefully examined every
month ; the presence of insects can be detected by the dust
beneath them. Where a collection is much infested with
destructive insects, benzine should be poured into the bottom
of the box or drawer, when the fumes and contact of the ben-
zine with their bodies will kill them. The specimens them-
selves should not be soaked in the benzine if possible, as it
renders them brittle.

Insect-cabinet. For permanent exhibition, a cabinet of shal-
low drawers, protected by doors, is most useful. A drawer
may be eighteen by twenty inches square, and two inches deep
in the clear, and provided with a tight glass cover. For constant



COLLECTING AND PRESERVING INSECTS.



93



use. boxes made of thin, well-seasoned wood, with tight-fitting
covers. MIV indispensable. For Coleoptera, Dr. Leconte recom-
mends that they be twelve by nine inches (inside measurement).
For the larger Lepidoptera a little larger box is preferable.
Others prefer boxes made in the form of books, which may be
put away like books on the shelves of the cabinet, though the
cover of the box is apt to be in the way.

The boxes and drawers should be lined with cork cut into
thin slips for soles ; such slips come from the cork-cutter about
twelve by four inches square, and an eighth of an inch thick. A
less expensive substitute is paper stretched upon a frame. Mr.
E. S. Morse has given in the American Naturalist (vol. I, p.
156) a plan which is very neat and useful for lining boxes in a.
large museum, and which
are placed in horizontal
show-cases (Fig. 72). "A
box is made of the re-
quired depth, and a light
frame is fitted to its in-
terior. Upon the upper
and under surfaces of this
frame, a sheet of white
paper (drawing or log-
paper answers the pur-
pose) is securely glued. Fig. 72.
The paper, having been previously dampened, in drying con-
tracts and tightens like a drum-head. The frame is then
secured about one-fourth of an inch from the bottom of the
box, and the pin is forced down through the thicknesses of
paper, and if the bottom of the box be of soft pine, the point
of the pin may be slightly forced into it. It is thus firmly held
at two or three different points, and all lateral movements are
prevented. Other advantages are secured by this arrangement
besides firmness ; when the box needs cleaning or fumigation,
the entire collection may be removed by taking out the frame,
or camphor, tobacco, or other material can be placed on the
bottom of the box, and concealed from sight. The annexed
figure represents a transverse section of a portion of the side
and bottom of the box with the frame. A, A, box ; B, frame ;




94 THE CLASS OF INSECTS.

P, P, tipper and under sheets of paper; C, space between
lower sheet of paper and bottom of box."

Other substitutes are the pith of various plants, especially
of corn; and palm wood, and " inodorous felt " is used, being
cut to fit the bottom of the box.

Leconte recommends that "for the purpose of distinguish-
ing specimens from different regions, little disks of variously
colored paper be used ; they are easily made by a small punch,
and should be kept in wooden pill-boxes ready for use ; at
the same time a key to the colors, showing the regions em-
braced by each, should be made on the fly-leaf of the catalogue
of the collection." He also strongly recommends that the
"specimens should all be pinned at the same height, since the
ease of recognizing species allied in characters is greatly in-
creased by having them on the same level."

He also states that "it is better, even when numbers with
reference to a catalogue are employed, that the name of each
species should be written on a label attached to the first speci-
men. Thus the eye is familiarized with the association of the
species audits name, memory is aided, and greater power given
of identifying species when the cabinet is not at hand." For
indicating the sexes the astronomical sign $ (Mars) is used for
the male, and $ (Venus) for the female, and 9 for the worker.

Transportation of Insects. While travelling, all hard-bodied
insects, comprising many Hymenoptera, the Coleoptera, He-
miptera, and many Neuroptera should be thrown, with their
larvae, etc., into bottles and vials filled with strong alcohol.
When the bottle is filled new liquor should be poured in, and
the old may be saved for collecting purposes ; in this way the
specimens will not soften and can be preserved indefinitely, and
the colors do not, in most cases, change. Leconte states that
"if the bottles are in danger of being broken, the specimens,
after remaining for a day or two in alcohol, may be taken out,
partially dried by exposure to the air, but not so as to be brit-
tle, and these packed in layers in small boxes between soft
paper ; the boxes should then be carefully closed with gum-
paper or paste, so as to exclude all enemies."

Lepidoptera and Dragon-flies and other soft-bodied insects
may be well preserved by placing them in square pieces of pa-



REARING LARVAE. ;;,

per folded into a triangular form with the edges overlapping.
Put up thus, multitudes can he packed away in tin boxes, and
will bear transportation to any distance. In tropical climates,
chests lined with tin should be made to contain the insect-
boxes, which can thus be preserved against the ravages of
white ants, etc.

In sending live larvae by mail, they should be inclosed in lit-
tle tin boxes, and in sending dry specimens, the box should be,
light and strong, and directions given at the post-office to
stamp the box lightly. In sending boxes by express they
should be carefully packed in a larger box, having an inter-
space of two inches, which can be filled in tightly with hay or
crumpled bits of paper. Beetles can be wrapped in pieces of
soft paper. Labels for alcoholic specimens should consist
of parchment with the locality, date of capture, and name of
collector written in ink. A temporary label of firm paper with
the locality, etc., written with a pencil, will last for several
years.

Preservation of Larvae. Alcoholic specimens of insects, in all
stages of growth, are very useful. Few collections contain al-
coholic specimens of the adult insect. This is a mistake. Many
of the most important characters are effaced during the drying
process, and for purposes of general study alcoholic speci-
mens, even of Bees, Lepidoptera, Diptera, and Dragon-flies are
very necessary.

Larvce, generally, may be well preserved in vials or bottles
of alcohol. They should first be put into whiskey, and then
into alcohol. If placed in the latter first, they shrivel and
become distorted. Mr. E. Burgess preserves caterpillars with
the colors unchanged, by immersing them in boiling water
thirty or forty seconds, and then placing them in equal parts
of alcohol and water. It is well to collect larvae and pupae
indiscriminately, even if we do not know their adult forms ; we
can approximate to them, and in some cases tell very exactly
what they must be.

REARING LARV^. More attention has been paid to rearing
Caterpillars than the -young of any other suborder of insects,
and the following remarks apply more particularly to them, but



96 THE CLASS OF INSECTS.

very much the same methods may be pursued in rearing the
larvae of Beetles, Flies, and Hymenoptera. Subterranean
larvae have to be kept in moist earth, aquatic larvae must be
reared in aquaria, and carnivorous larvae must be supplied
with flesh. The larvae of Butterflies are rare ; those of
moths occur more frequently, while their imagos may be
scarce. In some years many larvae, which are usually rare,
occur in abundance, and should then be reared in numbers.
In hunting for caterpillars bushes should be shaken and
beaten over newspapers or sheets, or an umbrella ; herbage
should be swept, and trees examined carefully for leaf-rollers
and miners. The best specimens of moths and butterflies are
obtained by rearing them from the egg, or from the larva or
pupa. In confinement the food should be kept fresh, and the
box well ventilated. Tumblers covered with gauze, pasteboard
boxes pierced with holes and fitted with glass in the covers, or
large glass-jars, are very convenient to use as cages. The bot-
tom of such vessels may be covered with moist sand, in which
the food-plant of the larva may be stuck and kept fresh for
several days. Larger and more airy boxes, a foot square, with
the sides of gauze, and fitted with a door, through which a bot-
tle of water may be introduced, serve well. The object is to
keep the food-plant fresh, the air cool, the larva out of the sun,
and in fact everything in such a state of equilibrium that the
larva will not feel the change of circumstances when kept in
confinement. Most caterpillars change to pupae in the autumn ;
and those which transform in the earth should be covered with
earth, kept damp by wet moss, and placed in the cellar until the
following summer. The collector in seeking for larvae should
carry a good number of pill-boxes, and especially a close tin
box, in which the leaves may be kept fresh for a long time.
The different forms and markings of caterpillars should be
noted, and they should be drawn carefully together with a leaf
of the food-plant, and the drawings and pupa skins, and per-
fect insect, be numbered to correspond. Descriptions of cat-
erpillars cannot be too carefully made, or too long. The
relative size of the head, its ornamentation, the stripes and
spots of the body, and the position and number of tubercles,
and the hairs, or fascicles of hairs, or spines and spinules,



ENTOMOLOGICAL WORKS. 97

which arise from them, should be noted, besides the genonil
form of the body. The lines along the body are called f/o/W,
if in the middle of the back, subdorscd; if upon one side. ////-
era/, and wntr<if when on the sides and under surface, or stig-
matal if including the stigmata or breathing pores, which are
generally parti-colored. Indeed, the whole biography of an
insect should be ascertained by the observer ; the points to
be noted are :

1. Date 1 , when and how the eggs are laid; and number, size,
and marking of the eggs.

2. Date of hatching, the appearance, food-plant of larva,
and number of days between each moulting ; the changes the
larva undergoes, which are often remarkable, especially before
the last moulting, with drawings illustrative of these ; the hab-
its of the larva, whether solitary or gregarious, whether a day
or night feeder ; the Ichneumon parasites, and their mode of
attack. Specimens of larvae in the different moultings should
be preserved in alcohol. The appearance of the larvae when
full-fed, the date, number of days before pupating, the forma-
tion and description of the cocoon, the duration of larvae in the
cocoon before pupation, their appearance just before changing,
their appearance while changing, and alcoholic specimens of
larvjii in the act, should all be studied and noted.

3. Date of pupation ; description of the pupa or chrysalis ;
duration of the pupa state, habits, etc. ; together with alcoholic
specimens, or pinned dry ones. Lepidopterous pupae should be
looked for late in the summer or in the fall and spring, about
the roots of trees, and kept moist in mould until the imago
appears. Many Coleopterous pupae may also occur in mould,
and if aquatic, under submerged sticks and stones, and those
of borers under the bark of decaying trees.

4. Date when the insect escapes from the pupa, and method
of escape ; duration of life of the imago ; and the number of
broods in a season.

ENTOMOLOGICAL WORKS. The titles of a few of the most im-
portant works on Insects are given below. The more advanced
st in lent should, however, possess Dr. Hagen's Bibliotheca En-
tomologica, 8vo, 2 vols., Leipzig, 1862-3, which contains a

7



98 THE CLASS OF INSECTS.

complete list of all entomological publications up to the year
1862. Besides these he should consult the annual reports on
the progress of Entomology published in AViegmann's Archiv
fiir Naturgeschichte, begui^ in 1834, and continued up to the
present time ; and also Gunther's Zoological Record (8vo, Van
Voorst, London), beginning with the year 1864. Occasional
articles are also scattered through the various goA r ernment re-
ports, and those of agricultural societies and agricultural
papers.

GENERAL WORKS.

The works of Sivammerdam, Malphighi, Leeuwenhoek, Lyonnet, Serres, MecKd,

Jiamdohr, Suckoiv, Merian, and Herbst.
Reaumur, Rene Ant. de. Memoires pour servir a 1' Histoire ties Insectes. Paris, 1734

-1742, 7 vols. 4to.
Roesel, Aug. Joh. Der monatlich nerausgegeben Insekten-Belustigung. Niirnberg,

1740-1701, 4 vols. 4to, illustrated.
Geer, Carl de. Memoires pour servir a 1' Histoire des Insectes, 1752-1778, 7 vols.

4to.

Linnaeus, Carolus. Systema Naturae, 1735. 12th edition, 1706-17C8.
Fabricius, Joh. Christ. Systema Entomologia?, 1775, 8vo.

. Genera Insectorum, 1777, 8vo.

. Species Insectorum, 1781. 2 vols. 8vo.

. Mantissa Insectorum, 1787, 2 vols. 8vo.

. Entomologia Systematica, 4 vols. 8vo, 1792-94.

Cramer, P. Papillons exotiques des trois parties dii monde. 4 vols. 4to, 1775-82.
Stoll, Casper. Supplement to Cramer's Papillons exotiques. 4to, Amsterdam,

1787-ni.
Smith, J. E., and Abbot, John. The Natural History of the Rarer Lepidopterous

Insects of Georgia. Fol. Plates. London, 175)7.
LatreiUe, Pierre Andre. Precis des caracteres generiqtie des Insectes, 1790, Svo.

. Genera Crustaceorum et Insectorum, 4 vols. Svo, 1806-1809.

. Consideration generates sur P Ordre naturel des Animaux composant

les Classes des Crustaces, des Arachnides et des Insectes.

. In Cuvier's Regne animal, Svo, 1810.

. Families naturelles du Regne animal, Svo, 1825.

Cours d' Entomologie, Svo, 1831.



Fabric.ius, Otho. Fauna Groenlandica. Hafniae, 1780, 8vo. Contains Libellula

Virgo (erroneously), Phryganea rhombica, Termes divinatorium, etc.
Drury, Dreio. Illustrations of Natural History, etc. London, 1770-1782, 4to,3 vols.

(ed. Westwood, 1837). Numerous species are figured and described.
Treviranus, G. R. Vermischte Schriften anatomischen und physiologischen luhalts

Bd. 1 u. 2. Gb'ttingen, 181C-17, 4to.

Mac Leny, W. S. Hora Entomologies, 2 vols. London, 1819.
Meigen, F. W. Systematische Beschreibung der bekannten europaischen zweiflu-

geligen Insecten. 7 vols. Aachen and Hamm, 1818-1835. (Although this work

contains only European species, many of them are common to both continents.)
Say, T. American Entomology. 3 vols. With plates. Philadelphia, 1824, 25, 28.
. Complete Writings on the Entomology of North America, edited by J. L.

Leconte, M. D. 2 vols. Svo, colored plates. New Yoi'k, 1859.
Baer, K. E. v. Beitrage zur Kentniss der niedereu Thiere. (Extracted from Nova

Acta Acad. Leopold. Carolin. xiii. 2, 1827.)



ENTOMOLOGICAL WORKS. 99

Falisnt <lp nfnurrris, A. J. Insectes recueillis m Afrique et en Amerique, dans les
royaiunes d' <>\vare et de I'cnin, a Samt-Domingue et dans les Etats-Unis, pen-