Directions for Collecting and Preserving Insects Part 3

Suborder PLATYPTERA ([Greek: platys], flat; [Greek: pteron], wing).

Under this head are grouped the White-ants (_Termitidae_), the Bird-lice (_Mallophaga_), and the Book-mites (_Psocidae_). The suborder receives its name from the fact that in the case of the winged forms the wings, when at rest, are usually laid flat upon the back of the insect. The Mallophaga, or Bird-lice, are degraded wingless insects, and are parasitic chiefly on birds, but also on mammals. In shape of body and character of the mouth-parts they are most nearly allied to the Psocidae.

The latter family includes both winged and wingless forms, the Book-mites belonging to the latter category. The winged forms may be ill.u.s.trated by the common species, _Psocus venosus_ (see Fig. 40). The legs and antennae are long and slender and the wings are folded roof-like over the body when the insect is at rest. They feed on lichens and dry vegetation.

The Termitidae are represented in this country by the White-ant (_Termes flavipes_), which is frequently so destructive to woodwork, books, etc.

The term White-ant applied to these insects is unfortunate, as in structure they are widely separated from ants and resemble them only in general appearance and also in their social habits. Like the ants they live in colonies and have a number of distinct forms, as winged and wingless, males and females, and workers and soldiers.

[Ill.u.s.tration: FIG. 40.--_Psocus venosus._ (From Comstock.)]

Suborder PLECOPTERA ([Greek: plektos], plaited; [Greek: pteron], wing).

Closely allied to the latter suborder is the suborder Plecoptera, which includes the single family Perlidae or Stone-flies. The larvae and pupae of these insects are aquatic, being often found under stones in water, whence the name. The adults are long, flattened insects, with long antennae. The wings are ample and are somewhat folded or plaited, from which character the suborder takes its name.

[Ill.u.s.tration: FIG. 41.--A Stone-fly (_Pteronarcys regalis_). (From Comstock.)]

Suborder ODONATA ([Greek: othous], tooth). This includes the Dragon-flies or Libellulidae, the most common and the best known of the Neuroptera. The larva and the active pupa or nymph are aquatic and are predaceous, as is also the adult. A common species is represented at Fig. 33.

The Suborder EPHEMEROPTERA ([Greek: ephemeron], a day-fly; [Greek: pteron], wing) comprises the May-flies, or Ephemeridae (see Fig. 42).

These insects are very fragile and are often attracted in enormous numbers to electric lights. They have large front wings, while the hind wings are small, rudimentary, or wanting. They are furnished with two or three very long, jointed, threadlike caudal appendages. The larval and nymphal stages are pa.s.sed in the water and aquatic vegetation furnishes the food, although some species may be predaceous. The adults have very rudimentary mouths and eat nothing; their term of life is also very limited, not exceeding 2-4 days.

[Ill.u.s.tration: FIG. 42.--A May-fly (_Potamanthus marginatus_). (From Packard.)]

Suborder THYSANURA ([Greek: thysanos], ta.s.sel; [Greek: oura], tail).

This suborder comprises minute, degraded insects commonly known as Spring-tails, Bristle-tails, Fish-moths, Snow-fleas, etc. They occur in damp situations and also infest books, wall-paper, etc., eating the starch paste in the book-bindings, or beneath the wall paper. They comprise very primitive forms and are interesting because they are supposed to represent the original stock from which the higher orders of insects have sprung. They are wingless, usually with simple eyes, and clothed with scales, and undergo no metamorphosis. Some of them, as the Fish-moth (_Lepisma sp._), run very rapidly and are furnished at the end of the body with a number of long bristles. In other forms these a.n.a.l bristles or stylets are united at the base and bent under the body and become a powerful jumping organ, giving them the very appropriate name of Spring-tails.

[Ill.u.s.tration: FIG. 43.--(_Lepisma 4-seriata_). (After Packard.)]

COLLECTING.

GENERAL CONSIDERATIONS.--"Few departments of natural history offer greater inducements or facilities to the student than Entomology. He need not pa.s.s his threshold for material, for it may be found on every hand and at all seasons. The directions for collecting, preserving, and studying insects might be extended indefinitely in detail, as volumes have already been written on the subject; but the more general and important instructions are soon given.

"Beginners are very apt to supply themselves with all sorts of appliances advertised by natural history furnishing stores. Many of these appliances, when it comes to real, practical field-work, are soon abandoned as useless inc.u.mbrances; and the greater the experience, the simpler will be the paraphernalia. My own equipment, on a collecting trip, consists chiefly of a cotton umbrella, a strong and narrow steel trowel or digger, a haversack slung across the shoulders, a cigar box lined with sheet cork, and a small knapsack attached to a waistbelt which girts a coat, not of many colors, but of many pockets, so made that in stooping nothing falls out of them. The umbrella is one of the indispensables. It shields, when necessary, from old Sol's scorching rays and from the pelting, drenching storm; brings within reach, by its hooked handle, many a larva-freighted bough which would otherwise remain undisturbed; and forms an excellent receptacle for all insects that may be dislodged from bush or branch. Opened and held inverted under a bough with the left hand, while the right manipulates a beating-stick, cut for the occasion, it will be the recipient of many a choice specimen that would never have been espied amid its protective surroundings. Some collectors use an umbrella painted or lined on the inside with white, to facilitate the detection of any object that drops into it; but as there are fully as many, if not more, pale and white insects as there are dark or black ones, the common dark umbrella is good enough for all ordinary purposes; and if any improvement on the ordinary cotton umbrella is desired, it should be in the way of a joint or knuckle about the middle of the handle, which will facilitate its packing and using. The trowel is valuable for prying off the loosened bark from old trees, whether felled or standing, and for digging into the ground or into decaying stumps and logs. The haversack is for the carriage of different kinds of boxes (those made of tin being best) intended for larval and other forms which it is necessary to bring home alive for breeding purposes; and if made with a part.i.tion so that the filled and empty boxes may be separated, all the better; it may also be used for nets and other apparatus to be mentioned, and for such provender as is necessary on the trip. The knapsack may be made on the plan of a cartridge box, of stout canvas or leather, and should be of moderate size and slung onto the belt so as to be slipped to any part of the waist and not hinder free bodily motion. It may be used to carry bottles, phials, and other small appliances, and should be accordingly part.i.tioned and furnished with loops or pockets on the inside. The cigar-box is for the reception of pinned specimens, and may be slipped onto the belt, or b.u.t.toned to the trousers by means of leather.

"The greatest requisites in collecting are a pair of sharp eyes and ready hands, with coolness and self-possession; but a few traps will materially aid. One of the most important is the hand-net, which may be made so as to subserve the two purposes of a sweeping and an air-net."

[Ill.u.s.tration: FIG. 44.--The b.u.t.terfly net-frame.]

"The frame of the net which I use is ill.u.s.trated herewith (Fig. 44), and will be found strong and serviceable and conveniently portable. It is constructed as follows: Take two pieces of stout bra.s.s wire, each about 20 inches long; bend them half-circularly and at one end by a folding hinge having a check on one side, _b_. The other ends are bent and beaten into two square sockets, _f_, which fit to a nut sunk and soldered into one end of a bra.s.s tube, _d_. When so fitted, they are secured by a large-headed screw, _e_, threaded to fit into the nut-socket, and with a groove wide enough to receive the back of a common pocket-knife blade. The wire hoop is easily detached and folded, as at _c_, for convenient carriage; and the handle may be made of any desired length by cutting a stick and fitting it into the hollow tube _a_, which should be about 6 inches long. It is well to have two separate hoops, one of lighter wire, furnished with silk gauze or some other light material, for catching flying insects, and one which is stouter and furnished with a net of stronger material for sweeping non-flying specimens.

"Another still more simple, but less convenient frame, is thus described by my friend F. G. Sanborn, of Boston, Ma.s.s.:

'Make a loop of strong iron or bra.s.s wire, of about 3-16ths of an inch in thickness, so that the diameter of the loop or circle will not exceed 12 inches, leaving an inch to an inch and a half of wire at each end bent at nearly right angles. Bind the two extremities of the wire together with smaller wire (Fig. 45, _a_), and tin them by applying a drop of muriate of zinc, then holding it in the fire or over a gas flame until nearly red hot, when a few grains of block tin or soft solder placed upon them will flow evenly over the whole surface and join them firmly together. Take a Maynard rifle cartridge tube, or other bra.s.s tube of similar dimensions; if the former, file off the closed end or perforate it for the admission of the wire, and having tinned it in the same manner on the inside, push a tight-fitting cork half way through (Fig. 45, _c_) and pour into it melted tin or soft solder, and insert the wires; if carefully done, you will have a firmly constructed and very durable foundation for a collecting net. The cork being extracted will leave a convenient socket for inserting a stick or walking cane to serve as a handle.'

[Ill.u.s.tration: FIG. 45.--The Sanborn net-frame.]

"My friend, J. A. Lintner, of Albany, N. Y., makes very good use, in his ordinary promenades, of a telescopic fish-rod, with a head (Fig. 46) screwed on to one end, in which to fasten an elastic bra.s.s coil on which the net is drawn, but which when not in use sits snugly inside his silk hat.

[Ill.u.s.tration: FIG. 46.--Clamp of the Lintner net.]

"The bag should taper to the bottom, and in any case its length should be fully twice the diameter of the hoop, so that by giving the net a twist, the mouth may be closed and the contents thus secured. The sweeping-net may be protected around the hoop with leather, and in use should be kept in a steady and continued back-and-forth motion, over and touching the plants, until the contents are to be examined; when, by placing the head at the opening and quietly surveying the restless inmates, the desiderata may be secured and the rest turned out. A sudden dash of the air-net will usually lay any flying object at the bottom. A net for aquatic insects may be made on the same principle, but should be stout, with the meshes open enough to allow free pa.s.sage of water, and the bag not quite as deep as the diameter of the hoop. A forceps net, which consists of two gauze or bobbinet covered frames, having riveted handles, so as to close like a pair of scissors, is employed for small insects; but I find little use for it. A coa.r.s.e sieve, together with a white towel or sheet, will be found of great service for special occasions, particularly in the spring, when the search for minute insects found under old leaves, or for pupae around the b.u.t.ts of trees, is contemplated. With the sheet spread on the ground, and a few handfuls of leaves and leafy mold sifted over it, many a minute specimen will be separated from the coa.r.s.er particles and drop to the sheet, where the eye may readily detect it. Conversely, the earth taken from around trees may be sifted so as to leave in the sieve such larger objects as pupae, etc. Another favorite plan, with some collectors, of obtaining specimens, especially night-flying moths, is by 'sugaring.' This consists of applying to the trunks of trees or to strips of cloth attached to the trees some sweet, attractive, and stupefying preparation. Diluted mola.s.ses or dissolved brown sugar, mixed with rum or beer, is most frequently employed. I have found sugaring of little use till after the blossoming season, and it is almost impossible to so stupefy or intoxicate an insect that it will remain upon the sugared tree till the next morning. I generally sugar at eve, and visit the tree several times between sundown and midnight, armed with wide-mouthed killing-bottles and accompanied by a second person, who carries a dark-lantern. Isolated trees, on the edges of woods, give the best results. Everybody knows how some poor moths will persist in flitting around a light until they singe their wings; and, as many insects are strongly attracted to bright artificial light, it may be employed with good results, especially during warm and damp evenings. The collector should never go unprovided with a small box or tube full of different sized pins (a corked cartridge-tube makes a good box,) a pair or two of forceps, a pair of scissors, a little mucilage, and the killing apparatus to be described."

With these general remarks, it will be well to consider some of the important paraphernalia more in detail.

COLLECTING APPARATUS.

_The Sweeping Net._--A mult.i.tude of insects of all orders feed or rest on gra.s.ses 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 b.u.t.terfly 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 b.u.t.terfly net, but otherwise it may be made on the same plan.

[Ill.u.s.tration: 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 bra.s.s or iron, either of one piece or of two pieces, and fastened to the handle or stick in the same way as the b.u.t.terfly net. The bag need not be as long as in the b.u.t.terfly 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 pa.s.ses 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 ill.u.s.trated 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 bra.s.s rings are slipped. These must be but little larger than the diameter of the wire. These little bra.s.s 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 compa.s.s. When unfolded and brought together, it screws into a ferrule which may be attached to a cane or a special handle.

[Ill.u.s.tration: 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 gra.s.s. 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.

[Ill.u.s.tration: 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 coa.r.s.e material, _e. g._, "gra.s.s cloth," coa.r.s.e 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.

[Ill.u.s.tration: FIG. 50.--The Water Net. (After Packard.)]

_Water Dip Net._--The small water sieve, shown in the accompanying ill.u.s.tration (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 sc.r.a.pe 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.

[Ill.u.s.tration: 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 circ.u.mference 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 b.u.t.terfly 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 b.u.t.terfly net, 2 feet or more in diameter.

[Ill.u.s.tration: FIG. 52.--The Umbrella and its mode of use. (After Kiesenwetter.)]

_The Beating Cloth._--A very simple subst.i.tute 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 subst.i.tute 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.

[Ill.u.s.tration: FIG. 53.--The umbrella beating and sweeping net (original).]