_The Sweeping Net._--A multitude of insects of all orders feed or rest
on grasses and other low plants. Upon close inspection of these plants a
careful observer will be able to secure, without any instruments, not
only many mature insects, but also many larvae in connection with their
food-plants. This is laborious and slow work, only necessary on special
occasions. The beating net, which is constructed on the same general
plan as the butterfly net, is valuable here as a time saver. By holding
the handle of the net firmly in one hand and quickly sweeping over the
plants first from right to left, and then, after quickly turning the net
again, sweeping from left to right, most insects coming within reach of
the sweep will fall into the bag and may be easily taken out and put
into the collecting-vials. From this mode of operation it is evident
that the sweeping net must be stronger in all its parts than the
butterfly net, but otherwise it may be made on the same plan.
[Illustration: FIG. 47.--The Deyrolle Sweeping Net. _a_, net entire;
_b_, frame; _c_ and _d_, attachment of frame and handle (original).]
The ring should be rigid, made of brass or iron, either of one piece or
of two pieces, and fastened to the handle or stick in the same way as
the butterfly net. The bag need not be as long as in the butterfly net,
about 18 inches being sufficient, but it should be of stout cotton or
linen and the bottom should preferably be sewed in as a round piece, so
as to avoid corners. Care needs to be bestowed on the fastening of the
bag on the ring, for by the use of the net the part of the bag sewed
around the ring is soon chafed through. To prevent this a strip of
leather is sewed over the cotton along the rim, but since even this must
be frequently renewed some other devices are used to give greater
durability to the net. In the pattern of a beating-net originally sold
by Deyrolle in Paris, the metal ring was flattened, with the narrow edge
pointing upwards and the broad side pierced with holes at suitable
intervals and grooved on the outer surface between the holes. The bag is
sewed on to the inner side of the ring by stout twine, which passes from
one hole to the next and is thus prevented from coming in contact with
obstructive objects, and only the bottom of the bag wears and will need
to be occasionally mended or renewed.
Another method of preventing the tearing of the upper rim of the bag is
described and illustrated in Kiesenwetter's useful volume "Der
Naturaliensammler" from which I shall frequently have occasion to quote.
In this net the main ring is of rounded iron wire on which a number of
brass rings are slipped. These must be but little larger than the
diameter of the wire. These little brass rings should not be more than
30 mm. or at most 40 mm., distant from each other, and to them the upper
rim of the bag is sewed with very strong twine and is thus protected
from wear and tear. The handle or stick of the net should be firmly and
solidly attached to the ring and should be stout and not liable to
break. I prefer a rather short stick, say not longer than two feet.
I figure herewith the ring of a very convenient net for sweeping or
beating purposes. It has the advantage of being for sale on the market,
and in fact is an ordinary fishing dip net of small size. It is hinged
in three places, as shown in the figure, and folds into very small
compass. When unfolded and brought together, it screws into a ferrule
which may be attached to a cane or a special handle.
[Illustration: FIG. 48.--Beating net, opened and attached to handle,
with frame of same folded. (After Kiesenwetter.)]
The beating net can be successfully used at almost every season of the
year. Even on warm days in winter time many specimens can be swept from
the dead grass. So long as the dew is on the plants or in rainy weather
no beating should be attempted, as the more delicate species are more or
less spoiled by the moisture. After one or two minutes' sweeping the
contents should be examined. Those insects which are quick to take wing
or which are good runners should first receive attention; the less
active can then be examined more at leisure. The desiderata are then
disposed of, the rest thrown away, and the beating renewed.
[Illustration: FIG. 49.--Folding ring for beating net (original).]
The beating net is an important instrument for collecting all insects
excepting mature Lepidoptera, which are apt to get rubbed. Many larvae,
especially of Lepidoptera, are caught by beating and are mostly in good
condition, but it is usually difficult to ascertain the food plant.
_The Water Net._--The numerous insects or insect larvae which live in the
water can not be conveniently collected without the use of a net, except
where they live in small shallow streams or creeks with gravelly or
stony bottoms. A suitable water net can readily be made by using the
frame of the beating net and attaching to it a rather short bag of some
coarse material, _e. g._, "grass cloth," coarse millinet. The mode of
operation with this net is very simple: if some insect is seen swimming
in the water, the net is carefully brought beneath the specimen, which
is thus lifted out of the water. Most water insects are, however, not
seen swimming about freely, but hide amid the various plants, mosses,
etc., or in the mud at the base of the plants, and they can best be
captured by dragging the net through these plants. When taken from the
water the net is more or less filled with mud and parts of plants, and
the water must be allowed to run out and the contents of the net spread
out on a cloth or on a flat stone, if such be at hand. The insects are
at first not readily seen, but after a short while they begin to emerge
from the mud and crawl about, and can readily be taken up with a
forceps.
[Illustration: FIG. 50.--The Water Net. (After Packard.)]
_Water Dip Net._--The small water sieve, shown in the accompanying
illustration (Fig. 51), and somewhat resembling in appearance a jockey
cap, is frequently of service in collecting the larvae of aquatic
insects, especially where it is necessary to scrape submerged stones or
timbers. In use it is fastened on the end of a cane or stick, and can be
easily made by any tinsmith.
[Illustration: FIG. 51.--Small Water Dip Net (original).]
_The Umbrella._--The umbrella, as already stated, is one of the most
useful instruments of the collector, since it enables him to obtain all
those numerous insects which live on the branches of trees, on shrubs,
and on other large plants. A common stout cotton umbrella is
sufficiently large, but is liable to get out of joint, and moreover the
specimens hide themselves under the ribs. It is well, therefore, to have
the inside of such umbrella lined along the ribs with muslin, or some
other material, preferably of a light color. An umbrella specially
constructed for entomological purposes is offered for sale by E.
Deyrolle, in Paris. It resembles a stoutly built common umbrella, but
has the inside lined with white linen and the handle has a joint near
the middle, so that the umbrella can be more conveniently held and more
readily packed away. The opened and inverted umbrella is held with the
left hand under the branch which the collector intends to relieve of its
entomological inhabitants, while the right hand, armed with a heavy
stick, is free to properly jar the branch. Care must be taken in the
jarring, lest the insects are knocked beyond the circumference of the
umbrella. The larger the umbrella the greater are the chances of making
rich captures, but the more difficult it becomes to manipulate,
especially where the woods are dense or where there are many vines, etc.
In the absence of an umbrella the butterfly net or the beating net can
be used.
A drawback to collecting with the umbrella is that many insects take
wing and escape before being secured. This can hardly be avoided, and
experienced collectors, in southern countries more particularly, have
found it advisable to discard the umbrella and to use in its stead a
very large butterfly net, 2 feet or more in diameter.
[Illustration: FIG. 52.--The Umbrella and its mode of use. (After
Kiesenwetter.)]
_The Beating Cloth._--A very simple substitute for the umbrella, and one
which can always be carried without inconvenience, may here be
described. It consists of a piece of common unbleached cotton cloth (1
yard square), to each corner of which a loop of stout twine is sewed.
Upon reaching the woods, two straight sticks, each about 5 feet in
length and not too heavy, but also not so small as to be liable to break
or to bend too easily, are cut from a convenient bush. The sticks are
placed crosswise over the cloth and fastened to the loops at the four
ends. This is easily and quickly done by making sliding loops of the
simple loops. The cloth is thus kept spread out between the sticks, and
forms a very good substitute for an umbrella. In beating, the sticks are
held at their intersecting points. When not in use one of the loops is
detached from the stick and the instrument can be rolled up and carried
under one arm without seriously interfering with other operations of the
collector. When laid on the ground, with the sticks on the underside,
this simple instrument may be advantageously used as a cloth on which
to sift or examine fungi, moss, pieces of bark, etc., and since the
cloth is always tightly expanded, it offers a smooth and level surface,
where examination of various objects can be made with ease and accuracy.
[Illustration: FIG. 53.--The umbrella beating and sweeping net
(original).]
_The Umbrella Net._--A very convenient form of net for both sweeping and
for use in place of an umbrella for beating has been devised by Dr.
George Marx. (See Fig. 53.) It is constructed from an old umbrella, as
follows: To the handle of the umbrella are attached two steel rods
working on hinges at the apex of the umbrella, as do the ordinary
umbrella ribs, and attached to the sliding piece of the umbrella in the
same manner, as shown at _a_. These rods should be about 21/2 feet long.
When the sliding piece is pushed up and caught behind the spring clip,
as shown at _b_, a circular loop is formed giving the framework for the
net. The latter, which should be comparatively shallow, is made of stout
muslin and sewed to the frame, as in the ordinary sweeping net. The
enlarged drawings _c_ and _d_ illustrate clearly the manner of
constructing the frame. The advantage of this net is its convenience in
carrying and its general usefulness, taking the place of both the
umbrella and the sweeping net. When not in use the frame is allowed to
assume the position shown at A, and the net may be wrapped about the
frame and the whole inserted in an ordinary umbrella cover.
_The Sieve._--This useful aid to good collecting has not been generally
employed by American entomologists. It facilitates the finding of small
insects living under old leaves, in moss, in decayed trees, in fungi, in
ants' nests, or in the ground. Any ordinary sieve about a foot in
diameter and with meshes of about one-fifth of an inch will answer,
though for durability and convenience of carriage one made of two wire
or brass rings and muslin (Fig. 54), as follows, is the best. The ends
of the wire netting should be bent around the ring so as not to project.
A piece of common muslin about 1 foot wide and long enough to go around
the circumference of one of the rings is then sewed together so as to
form a kind of cylinder or bag without bottom, and the upper and lower
rims of this bag are then sewed on around the two rings. The whole
instrument thus forms a bag, the top of which is kept open by the simple
wire ring, and the bottom is closed by the second ring covered with the
wire netting. After choosing a suitable locality a white cloth is spread
as evenly as possible on the ground; the collector then takes the sieve,
places therein two or three handfuls of the material to be sifted,
returns to his cloth, and, holding with his right hand the lower ring
and with the left hand the upper ring, shakes the sieve over the cloth.
The larger particles and specimens are retained in the sieve while the
smaller fall through the meshes on to the cloth. Care must be taken that
the siftings form an even and thin layer on the surface of the cloth, so
as to be easily examined from time to time. If the locality is favorable
many insects will be seen at the first glance crawling or running about,
and these can easily be picked up by means of a moistened brush, or with
the forceps. Many other insects, however, either feign death or, at any
rate, do not move until after the lapse of several minutes, and the
proper investigation of a single sifting often requires much time, and
patience will be more fully rewarded here than in any other mode of
collecting.
[Illustration: FIG. 54.--The sieve. _a_, wire netting (original).]
The size of the wire meshes given above is best adapted for sifting the
fragments of old decayed trees, which furnish the most frequent material
for the use of the sieve, but for sifting ants' nests, soil, etc., a
sieve with smaller meshes is desirable.
The sieve is indispensable to the Coleopterist, the Arachnologist, and
to the specialist in the smaller Hemiptera and Hymenoptera, but it is
also useful for most other orders, many interesting species existing
which can be secured in numbers only by this mode of collecting. Many
Tineidae and even Noctuidae hide under old leaves, but the specimens are
usually rubbed and rendered useless in the process of sifting. Many
larvae and pupae can, however, thus be obtained.
If the locality chosen for sifting prove to be a good one, it pays to
put the sifted material in a small sack and to carry it home where it
can be investigated at leisure, and with a greater thoroughness than is
usually possible outdoors. This sack can be easily arranged to be
attached to or drawn over the lower ring of the sieve, so that the
sifting can be done directly into the sack.
As a rule it may be said that very dry places are least productive,
while more or less moist places are apt to furnish a rich harvest. Old
wet leaves lying immediately along the edges of swamps, or wet moss,
harbor many interesting insects, but such wet material is sifted with
difficulty.
The sieve can be used with great advantage at all seasons of the year,
but more especially late in fall or early in spring, when so many
species are still hibernating.
_The Chisel._--For securing the many insects living or hiding under bark
of dying or dead trees an instrument of some sort is indispensable, as,
in most cases, the bark so firmly adheres to the wood that it cannot be
torn off with the hand. A stout pocket-knife will do good service, but
far better is a common chisel of medium size and with a short handle.
This chisel is also useful as an instrument for digging in the ground or
for investigating the interior of partly decayed logs.
_The Trowel._--Aside from the fact that many insects enter the ground
for the purpose of hibernation in various stages, there is a rich
subterranean life to be found during the summer. There are many
burrowing Coleoptera; many, if not most, ants construct subterranean
nests; the number of other fossorial Hymenoptera is very large, and
there are also various burrowing Orthoptera and many Lepidopterous larvae
which hide in the ground during the day. Some instrument for digging in
the ground is therefore of great importance, and while, as stated above,
the chisel will answer this purpose if nothing else be at hand, yet
there are other instruments which perform the work much quicker and more
thoroughly. The most available instrument is a rather small steel
trowel, such as can be had at the hardware stores in a great variety of
patterns, and which can be carried on excursions without much
inconvenience. One with a long and narrow blade, made very stout, I have
found very useful, though somewhat awkward to carry.
[Illustration: FIG. 55.--The collecting tweezers.]
_The collecting Tweezers._--In the picking up of specimens and
transferring them into the various bottles, vials, or boxes, the trained
collector will gather by hand the most delicate specimens without
injuring them. Yet this labor will be greatly facilitated by the use of
the tweezers or the brush. The former is a small, light pair of forceps,
made of steel or brass. It should be as pliable as possible, and the tip
should be narrow and rounded off and not pointed. It may be either
straight or curved at tip, according to individual preference.
[Illustration: FIG. 56.--Pinning forceps.]
[Illustration: FIG. 57.--Pinning forceps.]
Suitable tweezers may be obtained at the larger hardware stores or of
watchmakers. Excellent tweezers made of steel (see Fig. 55) are sold for
about 40 cents a pair by Codman, Shurtleff & Co., Tremont street,
Boston, Mass. Aside from their utility in picking up specimens from the
collecting cloth or the umbrella, the tweezers are indispensable for
extracting insects from cracks, or holes in timber, or from their
burrows in branches and stems of plants, or from places whence it is
impossible to dislodge them by hand. The larger "collecting forceps,"
sold by various dealers, do good service in certain emergencies, as when
large scorpions or other very large and ferocious insects are to be
secured.
[Illustration: FIG. 58.--Pinning forceps for Lepidoptera.]
For the handling of mounted insects various special forceps are
employed, a number of styles of which are shown at Figs. 56-8.
_The Brush._--A common camel's hair brush, of smaller or larger size
according to individual preference, is useful for picking up very small
or soft-bodied insects. For this purpose the brush is slightly moistened
with saliva, and the tip brought in contact with the specimen, which
then adheres to the brush, so that it can readily and without injury be
transferred to the collecting bottle or box. The brush is indispensable
also for preparing small specimens for the cabinet. If taken into the
field the handle of the brush should be of a bright color, otherwise the
brush is often lost.
[Illustration: FIG. 59.--The Fumigator. (After Kiesenwetter).]
_The Fumigator._--This is not used by American collectors, but there are
several patterns sold by European dealers. It is intended to smoke out
specimens that hide in otherwise inaccessible places, _e. g._, cracks in
the ground, holes in hard wood, etc. The accompanying figure and the
following description of a fumigator are taken from Kiesenwetter. A
common smoking-pipe mouthpiece (Fig. 59, _a_) with flexible rubber joint
(_b_) is attached to the cover (_c_) of a very large smoking-pipe head
(_d_). To the mouth (_e_) of the latter a rubber hose (_f_) is attached,
which has a convenient discharge at its end (_g_). The pipe is then
filled with tobacco, and the latter ignited by means of a piece of
burning tinder placed on top; the cover is then screwed on, and the
smoke can be directed to any desired point by blowing air through the
mouthpiece. The smoke from a common pipe or cigar is often useful. In
sifting in cold weather a puff of tobacco smoke gently blown over the
debris on the collecting cloth will induce many specimens to move, which
otherwise "play possum" and could not be observed; and, further, tobacco
smoke blown into holes and cracks in timber by means of an improvised
funnel made of a piece of paper will be the means of securing many rare
specimens.
_The Haversack._--In order that the above-mentioned instruments and the
various bottles, vials, and boxes which are needed for the preservation
of specimens may most conveniently and with the least impediment to the
collector be carried along on excursions, a haversack is indispensable.
This is made either of leather or, still better, of some waterproof
cloth, and should contain various compartments of different sizes; one
for stowing away the nets, the sieve, and the larger instruments, and
several smaller ones for boxes and vials--the whole so arranged that
each desired object can readily be taken out and that nothing will drop
out and get lost. The haversack is slung across the shoulders by means
of a leather strap, and a full field outfit need not be very heavy nor
seriously interfere with free bodily movements.
Many of the smaller objects are most conveniently carried in the pockets
of the coat, which acquires, therefore, some importance to the
collector. The coat should be of some durable stuff and provided with
many pockets, so arranged that in stooping nothing falls out of them.
_The Lens and Microscope._--In the examination of the minuter forms of
insect life the naked eye is not sufficient, and a hand-lens, or, for
more delicate work, the compound microscope will be found necessary. I
had, in my early experience, some difficulty in getting a satisfactory
hand-lens, and the use of a poor hand-lens in time injures the eyesight,
as I know by a year's rather disagreeable experience. For a hand-lens
the achromatic lenses formerly manufactured by A. K. Eaton, of Brooklyn,
N. Y., and now made by John Green, 35 Liverpool street, East Boston,
Mass., are most excellent in workmanship and are satisfactory in every
respect. A very good lens can also be purchased of any of the leading
manufacturers of microscopical apparatus in this country. The kind of
compound microscope to be purchased will depend upon the nature of the
work of the investigator. Very serviceable instruments are made by J. W.
Queen & Co., Philadelphia, Pa., and by the Bausch & Lomb Optical
Company, of Rochester, N. Y., and others. The German microscopes are in
many respects superior to those of American make, and if one has
sufficient means, I would recommend the purchase of one of the better
instruments of Zeiss's manufacture, which may be obtained either direct
from the manufacturers or through Queen & Co., or from the Boston
Educational Supply Company. Microscopic material, including slides,
cover glasses, instruments for mounting, mounting media, staining
fluids, etc., may be obtained of either of the firms named above.
Having thus indicated somewhat fully the general methods of collecting,
and the paraphernalia most desirable in collecting, it will be well to
go still further into detail, and in connection with the different
orders give some more specific information that will be valuable as a
guide not only to the general collector, but to the specialist.