GENERAL DIRECTIONS.--Owing to their hard outer skeleton, Coleoptera can
be collected, handled, and preserved with greater safety and with less
trouble than most other orders of insects. From this fact, and from
their very great diversity in form, Coleoptera have, next to the
Lepidoptera, always been favorites. As a consequence, there are now more
species described in this than in any other order, and in the large
museums they are much better represented than other insects. This rich
material has been studied by numerous and competent specialists, and the
classification of Coleoptera is at present more advanced and more
accessible than that of the other orders. This fact gives stimulus to
neophytes, and though the literature of our North American fauna is much
scattered and we are still in want of comprehensive works (with the
exception of the general "Classification" by Drs. Le Conte and Horn),
yet, except in a few hitherto neglected families and smaller groups, the
species are fairly well worked up.
On the other hand, our knowledge of the earlier states of Coleoptera is
yet very imperfect as compared with the Lepidoptera. Coleopterous larvae
are, with few exceptions (notably Coccinellidae and some Chrysomelidae),
much more difficult to find and rear, and their distinguishing
characters are more difficult to study. The few comprehensive works on
Coleopterous larvae that have been published are based on rather scant
material and none of them deal with the North American fauna.
[Illustration: FIG. 63.--A Ground-beetle (_Calosoma calidum_). _a_,
larva; _b_, adult.]
Coleoptera occur in all climates and in all localities. Species are
known from the highest northern latitudes ever reached by man, and in
the tropics they occur in an embarrassing richness of forms. They are
found in the most arid desert lands, in the depths of our subterranean
caves, and on our highest mountains up to the line of eternal snow. The
open ocean and the open water of our Great Lakes are the only regions
free from them. As a rule, the number of species gradually increases
from the Arctic regions toward the tropics, but it would be difficult to
decide, speaking of North America, whether or not the fauna of the
Middle States is poorer in the number of species than that of the
Southern States; or whether the beetles of the Atlantic slope outnumber
those of the Pacific States or those of the Central region. On the
Pacific slope the influence of the seasons on insect life is greater
than on the Atlantic slope. While in the latter region a number of
species may be found the whole year round, there is, in the more arid
regions of the West, an abundance of insect life during and shortly
after the rainy season, with great scarcity during the dry season,
except, perhaps, on the high mountains.
Few persons have had a more extended experience in collecting Coleoptera
than Mr. E. A. Schwarz, one of my assistants, and the following account
has been prepared by him at my request and is given _in extenso_.
WINTER COLLECTING.--There are more species of Coleoptera hibernating in
the imago state[3] than in any other order and winter collecting is
therefore most profitable in many respects. For instance, great swampy
tracts which are inaccessible in the summer season harbor an abundance
of rare Coleoptera, which either can not be found in summer time or are
found at that season with the greatest difficulty. At the approach of
winter, however, all or most of these species will leave the swamp and
seek drier ground, where they hibernate under old leaves, under bark of
trees, or in rotten stumps near the edge of the swamp. Such places will,
therefore, give a rich harvest to the Coleopterist late in the fall,
during warm spells in midwinter, and in very early spring. If the
temperature is below the freezing point, or if the ground is frozen
hard, no winter collecting should be attempted, first, on account of
sanitary considerations, and also because the Coleoptera then retreat
more deeply into the ground and can not be found so easily as when the
ground is free from frost. Other good collecting places in winter are
the accumulated old leaves along the edges of forests or under the
shrubbery along water courses, thick layers of moss, and the loose bark
of dead or dying trees, and, finally, also under the bark of certain
living trees, _e. g._ Pines, Sycamore, Shellbark Hickory. Digging in the
ground at the base of large trees or rocks also yields good returns. The
only instruments necessary for winter collecting are the sieve, the
chisel, and the trowel.
[3] There are a few species of Coleoptera known in Europe which belong
to the true "winter insects," _i. e._ such as appear in the imago state
only during winter time, but whether or not we have such species in our
own fauna has not yet been ascertained.
SPRING COLLECTING.--With the first days of spring, collecting becomes a
little more varied. The methods used for winter collecting can still be
continued with good success. Certain spring flowers, notably Willow
blossoms, will furnish many valuable species, which are not seen again
during the rest of the season.
[Illustration: FIG. 64.--A Lamellicorn (_Pelidnota punctata_). _a_,
larva; _b_, pupa; _c_, beetle; _d_, _e_, _f_, enlarged parts.]
_Myrmecophilous and Termitophilous species._--The early spring is also
the best time for collecting the Myrmecophilous and Termitophilous
Coleoptera. Termitophilous species have in North America hitherto been
found only in connection with the White-ants (_Termes flavipes_), and
the inquilinous beetles are found running among the White-ants in the
colonies under stones, loose bark of trees, and more numerously in the
interior of old infested trees. Myrmecophilous Coleoptera are by far
more numerous in species than the Termitophilous species and are found
among many species of ants which have their nests either under stones or
loose bark of trees, in stumps or logs, or which construct larger or
smaller hills. Upon uncovering a colony of ants under a stone, the
underside of the latter as well as the galleries of the ants in the
ground should be carefully examined for inquilines, which from their
greater or slighter resemblance to the ants are liable to be overlooked
by an inexperienced collector. If such colony of ants harbors a rare
beetle the subterranean part of the colony itself should be dug out and
sifted, but since from the stony nature of the ground this is not always
practicable it is to be recommended to carefully replace the stone under
which the colony has been found. Upon revisiting the spot again the next
day or even a few hours after the first visit additional specimens of
the inquilines are usually to be obtained on the stone or in the
superficial galleries of the ants. Ant colonies in hollow trees and in
rotten logs should be sifted and there is no particular difficulty
connected with this operation. Owing to the pugnacious character of the
hill-constructing ants it would seem to be a rather unpleasant task to
examine a strong and vigorous colony for inquilinous beetles, but the
collector must not mind being bitten and stung by the infuriated ants,
and after a little experience he will find that it is not such a
difficult thing after all to attack even the largest ant-hill. The only
thorough way of investigating such ant-hills is to sieve the same, which
can be easily done if the hill is composed of sticks and other vegetable
debris. If it is built of earth or sand the process of sifting is more
difficult and tedious. Another method of securing specimens of these
inquilinous beetles is to place flat stones or similar objects on the
surface of the ant-hill and to examine them occasionally, when the
beetles will be found on the underside of the traps.
_Spring Flights of Coleoptera._--On the first really warm days of spring
commences the "swarming" season of Coleoptera, when all winged species
are flying about, especially toward evening. On favorable days the
number of specimens and species that can thus be found is astonishingly
great, and this is one of the few occasions when the Coleopterist can
advantageously use a light butterfly net. The flying beetles preferably
alight and rest on the top of wooden fences (especially newly made
ones), on the railings of bridges, etc., where they can be easily seen
and secured, or they are attracted in great numbers by the white-painted
surface of buildings. This flying season lasts in the latitude of
Washington from the end of April to the middle of June, but favorable
days are not of frequent occurrence, since a peculiar combination of
atmospheric conditions appears to be necessary to induce the Coleoptera
to fly about in great numbers.
_Beach collecting._--Along the shores of the ocean and the Great Lakes
untold numbers of Coleoptera and other insects fall at this season into
the water, and, if the tides, the currents, and the winds be favorable,
they are washed ashore by the waves on the sandy beaches, where they
often form windrows several inches in height and width. If the collector
is happy enough to be at the right place on the right day he has then
the opportunity to pick up hundreds of rare species within a very short
time and without any trouble. Many of the specimens thus washed ashore
are dead and decayed, but the majority are alive and in excellent
condition. This "beach collecting" affords also an excellent opportunity
for the Hymenopterist and Hemipterist to secure large numbers of rare
species, but favorable days are also here of rare occurrence.
_Attracting by Lights._--On the beaches, day and night flying insects
can thus be captured. Away from the beach night-flying Coleoptera can
best be collected at the electric lights of our cities; but, as in the
Lepidoptera, not all night-flying species are attracted by the light.
Gas and other lights also attract Coleoptera, and the various "light
traps" that have been devised and described can advantageously be used
for collecting these insects.
_Traps._--The method of "sugaring," so important to the Lepidopterist,
is by far less favorable for collecting Coleoptera. Still, certain rare
Carabidae, Elateridae, and Cerambycidae are attracted by this bait, and the
Coleopterist should not entirely ignore this mode of collecting. There
are a few other methods of trapping certain Coleoptera. By laying out
dead mammals, birds, fishes, snakes, etc., on suitable places and so
that they are protected from dogs, rats, etc., the carrion-feeding
Coleoptera can be found in great abundance, but a cleaner and less
disagreeable method of obtaining them is to bury in the ground tin cans
or glass jars so that the top is even with the surrounding ground and to
bait them with pieces of meat, fried fish, boiled eggs, etc. Many
Curculionidae, Scolytidae, and numerous other wood-inhabiting species can
be successfully trapped in the following way: A number of branches,
preferably of only one kind of tree, are cut and tied up into bundles of
convenient size. The bundles are then laid on the ground in a shady
place or firmly fastened on trunks of trees. When the cut branches begin
to get dry they will attract many of these Coleoptera, which can then be
readily collected by shaking the bundles out over the collecting cloth.
[Illustration: FIG. 65.--An Elaterid (_Pyrophorus noctilucus_). (From
Packard.)]
_Freshets._--Freshets usually take place in springtime in most of our
rivers and creeks, and furnish the means of obtaining a multitude of
Coleoptera, among which there will be many species which can not, or
only accidentally, be found otherwise. These freshets, sweeping over the
low banks or inundating wide stretches of low land, carry with them all
insects that have been caught by the inundation. Intermingled with, and
usually clinging to, the various floating debris, these insects are
eventually washed ashore by the current at various points and the
Coleopterist should not miss this rare opportunity, but go out to the
river bank at a time when the water is still rising, or at least when it
has attained its highest point. Among, or on the washed up debris, a
multitude of Coleoptera of various families can be found, and the
specimens can either be gathered up on the spot or a quantity of the
debris be put in sacks and taken home, where it can be examined more
thoroughly and with greater leisure than out of doors. A day or so after
the floods have receded the washed up specimens will have dispersed and
only a few will remain in the debris for a longer period. Still more
profitable than the spring floods are the summer freshets, because a
larger and more diversified lot of Coleoptera is then brought down by
the water. A similar opportunity for collecting is offered near the
seashore if unusually high tides inundate the low marshes along the
bayous and inlets.
[Illustration: FIG. 66.--A Longicorn (_Prionus laticollis_).]
SUMMER COLLECTING.--During the latter part of spring and throughout the
whole summer, when the vegetation is fully developed, every possible
collecting method can be carried on with success, so that the beginner
hardly knows what particular method to use. There are stones to be
turned over; old logs, stumps, and hollow trees to be investigated;
newly felled or wounded trees to be carefully inspected; here a spot
favorable for sifting claims attention; promising meadows and low
herbage in the woods invite the use of the sweeping net; living or dead
branches of all sorts of trees and shrubs to be worked with the
umbrella; the mud or gravel banks of ponds, lakes, rivers, and creeks
afford excellent collecting places; the numerous aquatic beetles are to
be collected in the water itself; the dung beetles to be extracted from
their unsavory habitations; in the evening the electric and other lights
are to be visited, the lightning beetles chased on meadows and in the
woods, or the wingless but luminous females of some species of this
family to be looked for on the ground, and the trees and shrubs are to
be beaten after dark in search of May beetles and other nocturnal
leaf-feeding species which can not be obtained at daytime; and, finally,
some of the rarest Scarabaeidae and some other species fly only late at
night or again only before sunrise.
In view of this embarrassing multitude of collecting opportunities in a
good locality, the beginner is apt to be at a loss what course to
pursue. Experience alone can teach here, and only an expert collector is
able to decide, at a glance at the locality before him, what collecting
method is likely to produce the best results, and his judgment will
rarely be at fault.
It is impossible to go into details regarding the various collecting
methods, just mentioned, and only a few general directions can be given
regarding those methods which have not previously been alluded to.
_Collecting under Stones._--Turning over stones is a favorite method
among beginners and yields chiefly Carabidae, the larger Staphylinidae,
certain Curculionidae, and a multitude of species of other families.
Stones on very dry ground are productive, only early in spring or in the
fall, while those on moist ground, in the shade of woods, are good at
all seasons. In the Alpine regions of our mountainous districts,
especially above the timber line, collecting under stones becomes the
most important method, and is especially favorable along the edges of
snow fields. In often frequented localities the collector should
carefully replace the stones, especially those under which he has found
rare specimens. The neglect of this rule is one of the principal causes
for certain rare species having become extinct in the vicinity of our
cities.
_Collecting in rotten Stumps and Logs._--Success in collecting in rotten
stumps depends much upon the more or less advanced stage of decay as
well as upon the situation of the log and upon the particular kind of
wood. If the decay is very much advanced neither the loose bark nor the
interior of the log will harbor many Coleoptera excepting a multitude of
_Passalus cornutus_ and its larvae. If the decay is less advanced, but if
such log is exposed to the scorching rays of the sun, it will be far
less productive than a log in a shady situation. The investigation of
the bark of a favorably situated log in the right stage of decay does
not need any special instruction, but the decayed wood itself should be
pried off with a chisel or trowel, put in the sieve and sifted on the
collecting cloth. This is the best way of obtaining the numerous species
of rare Micro-coleoptera of various families that inhabit such places. A
"red rotten" oak or beech log is more favorable for this mode of
collecting than a "white rotten" of the same or other kinds of trees.
_Collecting in dying or dead Trees._--Dying or dead trees almost always
harbor a large number of Coleoptera and offer an excellent collecting
opportunity until the wood becomes thoroughly dry, which usually takes
place in large trees two or three years after the death of the tree, and
in less time with smaller ones. The bark of such trees is the best
collecting place for Cucujidae, Colydiidae, Scolytidae, Histeridae, etc.,
and it will be found that the shady side of the tree is more profitable
than the side exposed to the sun. The numerous Buprestidae, Elateridae,
Ptinidae, Cerambycidae, Melandryidae, etc., which breed in the wood can be
obtained only with difficulty. Some specimens may be cut out from their
holes by a skillful use of the knife or hatchet; others (especially the
Buprestidae) may be found resting on or crawling over the trunk in the
bright sunshine, while the more nocturnal species may be found on the
tree toward evening or after dark, when, of course, a lantern must be
used. A large proportion of the species living in the trunks of dead
trees also breed in the dead branches of otherwise healthy trees from
which they can be beaten into the umbrella, or where the use of the
knife is more practicable than in the large trunks. The trunks of
freshly felled trees attract numbers of Cerambycidae and Buprestidae and
have to be carefully looked over, while the drying foliage of such trees
affords an excellent opportunity for the use of the umbrella.
_Beating living Trees, Shrubs, and Vines._--The success of beating into
the umbrella branches of living trees and shrubs depends on the
particular kind of tree or shrub, on the condition and situation of
these, and largely also upon the season. Pine trees are very productive
from early in the spring to early in the summer, but much less so in
midsummer and later on. Young Oak trees or Oak shrubs are much more
preferred by the leaf-eating Coleoptera peculiar to this tree than the
older trees. The Beech, which, next to the Oak, is the best tree for
wood-boring species, harbors but few leaf-eating species. The leaves of
the Chestnut are also generally not attacked by Coleoptera; still a
surprising number of species can be beaten from this tree when it is in
blossom. There is not a single species of Coleoptera known to live in
the wood or to feed on the leaves of the Holly (_Ilex glabra_); still it
will pay the Coleopterist to beat this tree when it is in bloom. Trees,
shrubs, and vines in the interior of unbroken forest districts are, as a
rule, unproductive, while the edges of the woods, narrow strips of
hedges, and especially solitary trees are excellent collecting places.
In the Rocky Mountains, especially in the more southern sections, long
stretches of mountain slopes are occasionally perfectly bare of
vegetation with the exception of a few solitary, sickly-looking, and
dwarfed trees, but every one of these is a veritable gold mine to the
Coleopterist with his umbrella.
_Sweeping._--The use of the beating net continues profitable from spring
till fall, a different set of species appearing with each season. Low
and swampy meadows, meadows on the slopes of mountains or surrounded by
woods, low underbrush, and herbage in smaller patches of woods are very
good beating grounds. Dry and sandy meadows are less productive, but
harbor usually a different set of species on account of the difference
in the flora. Pastures and meadows much frequented by cattle and horses
are much less productive, and where a large number of sheep are kept
there is usually no chance for using the beating net, since neither
grass nor specimens are left. The lawns in our parks and gardens are
usually poor collecting ground on account of the limited variety of
plants in such places; but the few species found there occur in enormous
number of specimens. The endless stretches of our western prairies swarm
at the right season (in June) with numerous Coleoptera (mostly
Malachiidae, Chrysomelidae, Mordellidae, Curculionidae, etc.), provided
prairie fires have not swept too frequently over the place. Fires and
cattle produce a remarkable change in the flora and fauna of the
prairies; many indigenous species disappear or become scarce and are
replaced by a much smaller number of imported species.
[Illustration: FIG. 67.--A Dermestid (_Anthrenus scrophulariae_). _a_,
larva, dorsal view; _b_, larva, ventral view; _c_, pupa; _d_, adult--all
enlarged.]
Sweeping may commence in the forenoon as soon as the dew has
disappeared; it is less profitable in the heat of the midday, but
produces the best results late in the afternoon and more especially in
the short interval from just before sunset until dark. At this time many
rare Pselaphidae and Scydmaenidae, species of the genera _Colon_ and
_Anisotoma_, and other small Silphidae can be beaten from the tips of
grasses, all being species which can not, or only accidentally, be found
during daytime, when they hide between the roots of plants.
_Collecting on mud and gravel Banks._--The mud or gravel banks of
rivers, creeks, and stagnant bodies of water are inhabited, especially
early in summer, with an astonishing multitude of Coleoptera. Countless
specimens of smaller Carabidae (_Dyschirius_, _Clivina_, _Bembidium_,
_Tachys_, etc.) and Staphylinidae (_Tachyusa_, _Philonthus_, _Actobius_,
_Stenus_, _Lathrobium_, _Trogophlaeus_ and many other genera) will be
seen actively running over the mud or sand; many other specimens are
hiding under the pebbles in company with other species (_Cryptohypnus_,
_Georyssus_, etc.) or in little subterranean galleries (_Dyschirius_,
_Bledius_, _Heterocerus_). All these beetles must be collected by
picking them up with the fingers, an operation which, owing to the
activity of the specimens, requires some little practice. The beginner
will at first crush or otherwise injure many of the delicate specimens,
the capture of which is moreover by no means facilitated by the rapidity
with which most of them are able to take wing. The collector must
necessarily kneel down and he must not mind getting covered with mud. A
good device for driving these species out of their galleries or from
their hiding places under stones or in cracks of the ground is to pour
water over the banks, and this can in most cases be done with the hand.
Larger stones and pieces of wood or bark lying on the bank are favorite
hiding places of certain larger Carabidae (_Nebria_, _Chlaenius_,
_Platynus_, etc.), and should of course be turned over. Finally, the
moss growing on rocks and logs close to the water's edge, and in which,
besides other beetles, some rare Staphylinidae and the Byrrhid genus
_Limnichus_ can be found, should be scraped off and investigated on the
collecting cloth or on the surface of a flat rock, if such be
conveniently at hand.
_Collecting aquatic Beetles._--The fishing for water beetles in deeper
water by means of the water net has already been alluded to (p. [32]),
but many species live in shallow brooks with stony or gravelly bottom,
where the water net can not be used. The Dytiscidae and Hydrophilidae
living in such places usually hide under stones, and can in most cases
be easily picked up with the hand, or a little tin dipper or a spoon
will be found convenient for catching them. The species of the family
Parnidae are found on the underside of rough stones or logs which are
either partially or entirely submerged. They are more numerous, however,
in the moss or among the roots of other plants that grow in the water.
Such plants have to be pulled out and examined over the collecting
cloth.
[Illustration: FIG. 68.--A Tiger Beetle (_Cicindela limbata_), drawn by
Miss Sullivan--enlarged.]
_Collecting at the Seashore and on sandy Places._--A large number of
species belonging to various families live exclusively in the vicinity
of the ocean, some on the open beach, others along the inlets, bayous,
or salt marshes, and still others on the dry sand dunes. The Cicindelae
are actively running or flying about close to the water's edge and have
to be captured with the butterfly net. The remaining maritime species
live hidden under the seaweed and other debris cast up by the waves, or
in the sand (sometimes quite deep below the surface) beneath the debris
or between the roots of the plants growing on the dunes. The majority of
the maritime species do not appear before June (in the Middle States),
but the collecting remains good until September.
[Illustration: FIG. 69.--The Beaver Parasite (_Platypsyllus castoris_),
adult--greatly enlarged.]
In dry sandy places away from the seashore, the collecting at the roots
of plants is especially to be recommended, and the plants, and more
especially the bunches of coarse grasses usually growing in such places,
should be pulled up and shaken out over the collecting cloth. This mode
of collecting acquires a great importance in the arid regions of the
West and Southwest, where, in the warm season, nearly all Coleoptera are
hiding during daytime in the ground at the roots of plants.
_Collecting Dung-beetles._--The collecting of the numerous species
(_Hydrophilidae_, _Staphylinidae_, _Histeridae_, _Scarabaeidae_, etc.) which
live in the droppings of various animals is by no means an agreeable
task. The collector should provide himself with a pointed stick and
collecting tweezers, and must manage to pick up the specimens as best he
can. The larger specimens are best collected in alcohol, while the more
delicate species can be collected in a cleaner condition by removing the
droppings and sifting the ground beneath the same. Some species hide
deep in the ground beneath the droppings and have to be dug out. Summer
freshets, when pasture lands are inundated, offer an excellent
opportunity for collecting the dung-inhabiting species in a clean
condition.
_Night Collecting._--The beating of trees and shrubs after dark is a
good method of obtaining Lachnosternas and other species, and here the
collector will do well to secure the assistance of a companion, who
takes charge of the lantern and the collecting bottles, while the
collector himself works the umbrella.
FALL COLLECTING.--From the first of August the number of species
gradually diminishes, but late in the summer or early in fall quite a
number of other species make their appearance, _e. g._, some
Chrysomelidae, Cerambycidae, and many Meloidae. Many of these frequent the
blossoms of Golden-rods, umbelliferous and other late-flowering plants.
The fall is also the best season for collecting Coleoptera living in
fungi. Although puff-balls, toadstools, and the numerous fungi and
moulds growing on old trees, etc., furnish many species of Coleoptera
also earlier in the season, yet most fungi, and more especially the
toadstools, flourish best in the fall, and consequently there is then
the greatest abundance of certain species of Coleoptera. Decaying
toadstools are especially rich, and should be sifted, and the collector
should also not omit to examine the soil beneath them.
During the "Indian summer" there is usually a repetition of the "spring
flight" of Coleoptera, though on a smaller scale, and collecting on the
tops of fence posts and on whitewashed walls again becomes good. The
first really sharp frost causes these late species to disappear, and
winter collecting commences again.