Chapter III: Part 3

_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.

_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.

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.

COLLECTING LEPIDOPTERA.

In this order the importance of collecting the early states and of rearing the adult insects rather than of catching the latter should, if the collector has the advancement of knowledge and the greatest pleasure in mind, be insisted upon. Collected specimens, in the majority of cases, will be more or less rubbed or damaged and unfit for permanent keeping, and will always be far inferior to freshly reared specimens. All Lepidopterists, therefore, rely to a great extent upon breeding rather than upon field collecting. There are, however, many species of which the early states are still unknown, and these can only be taken by field collecting, and by attracting to various lights or traps. This subject, therefore, naturally falls into two categories--(1) the general collecting of the adult, and (2) collecting the early stages and rearing the perfect insects.

_Collecting the Adult._--The implements for the general collecting of butterflies comprise the collecting net, and in some cases the beating net, although the use of the latter will not often be called for. The Rhopalocera or Diurnals may be taken about flowers, and the best season is in the early spring. Most of them are double-brooded, and the second brood will be in the greatest abundance during July and August. They are, however, to be found throughout the summer. They are also to be looked for in the neighborhood of the food-plants of their larvae, and in the case of many species, examination of such plants affords the most satisfactory means of collecting. The food of butterflies is almost exclusively the nectar of flowers, but strangely enough they are also attracted to decaying animal matter, and many species, including rare forms, may be taken about decaying animal matter or resting on spots where dead animals have lain, or beneath which they have been buried. Moist spots of earth are also frequented by them, especially in dry seasons. Many of the larger butterflies, whose larvae feed on the taller shrubs and the foliage of trees, will be found fluttering about the open spaces in forests, but by far the larger number, as the Browns, the Blues, the Yellows, and the Whites, which develop on the lower herbaceous and succulent plants, will be found flying over fields, prairies, and gardens. Crepuscular and nocturnal Lepidoptera, comprising most of the Heterocera, the Sphingidae, Bombycids, Noctuids, etc., have different habits. The Sphingidae or Hawk Moths fly in early evening, and may be collected in quantity about such plants as the Honeysuckle, Thistle, Verbena, Petunia, etc. The Bombycids and many Noctuids also fly in the early evening, but mostly at night. The former, however, do not frequent flowers, except such as are the food-plants of their larvae, as their mouth-parts are rudimentary, and they take no nourishment.

Collecting by the aid of strong light is a favorite means for moths as well as other insects, and nowadays the electric lights in all large cities furnish the best collecting places, and hundreds of species may be taken in almost any desired quantity. In woods or in other situations they may be attracted to a lantern or to a light placed in an open window. Various traps have been devised, which comprise a lamp with apparatus for retaining and stupefying the insects attracted to the light. The common form is made by providing a lantern with a strong reflector. Under the light a funnel several inches larger than the lantern reaches down into a box or bottle containing the fumes of chloroform, ether, or benzine.

Mr. Jerome McNeill describes at length and figures in the _American Naturalist_, Vol. XXIII, p. 268-270, an insect trap to be used in connection with electric lights. It consists of a tin pail or can charged with cyanide after the manner of a collecting bottle, which is attached beneath the globe of the electric light.

The insects attracted by the light strike against a vertical tin screen fixed above the can and fall into a tin funnel the small end of which enters and closes the mouth of the can, and they are thus conducted into the last. A support or post in the center of the can bears a hollow tin cone, the apex of which is pierced with a number of small holes to admit light, and enters and partly closes the lower end of the funnel. The entire interior of the can is painted black and the chief light comes through the holes in the apex of the interior cone. The entrapped insects endeavor to escape by crawling up the central post towards the light coming through the small holes in the end of the cone rather than by the entrance slit about the latter and fall back repeatedly until overcome by the cyanide.

Many of the Lepidoptera will be ruined by the beetles and other insects or by their own ineffectual attempts to escape, but Coleoptera, Hymenoptera, Neuroptera, and Hemiptera are secured in satisfactory condition.

Many of the devices are very complicated and can not be described in this connection. The nocturnal species, also, fly into our houses, and this is especially the case in the country, and an open window, with a strong light reflected onto a table covered with either a white paper or a white cloth will keep one busy, on favorable nights, in properly taking care of the specimens thus attracted.

Another favorite method of collecting moths early in the evening, or as late as or later than midnight, is by sugaring. This consists in smearing a mixture of sugar and vinegar, or some similar compound, on the bark of trees or on the boards of fences, and visiting the spot from time to time to collect the moths attracted to the bait. It has been found that the use of beer or some other alcoholic liquor, as rum or brandy, with the sugar or molasses water, greatly adds to its efficiency in attracting the moths. This method of collecting moths will be found especially efficient on warm, moist, cloudy nights. The collector should be provided with a dark lantern and a good net, and a number of wide-mouthed cyanide collecting bottles. The smearing should be done just before dark, and I have always found that better success attends this method of collecting when two are engaged in it--one to hold a bull's eye lantern while the other bottles the specimens. Experience will soon teach the surest way of approaching and capturing the specimens.

For collecting Microlepidoptera, in addition to the ordinary net, some special apparatus will be found very essential. Lord Walsingham makes use of a special glass-bottomed pill-box, with which to capture specimens, and the satisfactory nature of the work done with this box, and the dexterity acquired by practice with it, I can vouch for by personal experience. These glass pill-boxes are useful, also, in admitting of the examination of specimens, so that worthless or common species can be discarded and only desired forms kept. The method of holding these boxes is illustrated in the accompanying illustrations. (Figs. 72, 73.) A drop of chloroform on the bottom of the box at once stupefies the capture so that it can be taken out and otherwise disposed of.

The necessity of rearing to obtain perfect specimens is even more important in the case of the Microlepidoptera than with the larger forms, and many species are very easily reared and can thus be obtained in quantity. The Micros are abundant from early spring to late fall about shrubbery, in open fields, and along the edges of woods. They are, for the most part, day fliers, being on the wing chiefly in the latter part of the day and early evening. As soon as collected they should be transferred to pill-boxes and the greatest care should be exercised to avoid mutilating them, as the slightest touch will denude them of a portion of their scales or break their limbs or antennae. Lord Walsingham thus gives his experience in collecting Micros:

I go out with a coat provided with large pockets inside and out, containing an assortment of pill-boxes, generally of three sizes, glass-bottomed pill-boxes preferred, a bag slung over my shoulder, and a net. Unless searching for particular day-flying species, I prefer the last three hours before dark. As the sun goes down many species move which do not stir at other times. I watch the tops of the grass, the stems of the flowers, the twigs of the trees; I disturb leaves and low-growing plants with a short switch and secure each little moth that moves, taking each out of the net in a separate pill-box, selected according to the size of the insect, as he runs up the net to escape. Transferring the full boxes to the bag I continue the process until moths cease flying or night sets in. Many species can be taken with a lamp after dark.

_Collecting the early States._--The careful entomologist who prides himself on the appearance of his specimens, will, as stated above, rely largely on collecting the early states and on rearing the insects, for his material. The Macrolepidoptera have either a single or two broods, or more, in a season, and the collection of the early states will be greatly facilitated if a knowledge of the insect's life-habits is first obtained. The eggs are often found on the food plants of the species, and where they are deposited in masses they afford a very easy method of getting the larvae in numbers. In many cases, however, the eggs are deposited singly and their discovery then becomes a difficult matter.

More satisfactory in some respects is the method of obtaining the eggs from captured gravid females, and the general collector should always be on the lookout for females of rare species from which he may be able to obtain eggs. A single battered female may, in this way, be the source of large numbers of excellent reared specimens. Many rare Lepidopterous larvae may be obtained by the use of the beating net and by beating foliage over an umbrella. A very satisfactory method consists in collecting pupae, which may frequently be found in numbers about the bases of the trees on which the larvae feed. Many larvae of the large family of Owlet Moths (_Noctuidae_) are found either on the surface of the ground or under various substances, while others burrow into the stems of the different herbaceous plants, some being subaquatic and feeding on the underside of leaves or in the stems of aquatic plants. In the case of Microlepidoptera, their habit as larvae, of mining leaves or tying or webbing them together, affords an easy means of detecting their presence in most cases. The miners are easily noticed by the discolored spots on the leaves or the wavy, pale, or brown lines marking their burrows. The presence of others is indicated by the leaves being drawn together and united with webs, or withered and brown from being skeletonized by the larvae. Many species are case-bearers, and live upon the leaves and branches of trees and plants, dragging their cases along with them. Others burrow in grasses or in the stems of plants or the trunks of trees, or in fungi. In the case of the leaf-miners and leaf-tiers, little difficulty is experienced in rearing the imagoes.

The care of the larvae, the outfit required, and the methods of breeding will be described in later sections.

COLLECTING HEMIPTERA.

For the most part the directions for collecting Coleoptera will apply to this order of insects equally well, especially so far as concerns the first section of the order (Heteroptera), and the higher families of the second section (Homoptera). A few directions may be given for the lower forms, including the Aphididae, Coccidae, Aleurodidae, and Psyllidae, and the suborder Parasita, including the degraded forms which infest man and the lower animals. The Plant-lice or Aphides should always be collected in connection with their food-plants, and it is very essential also to collect the same species at different seasons of the year to obtain the different forms or generations, which frequently present very marked differences. It is also very necessary to secure the winged forms, which are usually produced toward autumn, and without which the species are not easily identified. The Bark lice or Scale-insects should also be collected in connection with the leaves or twigs which they infest. The males of these insects are minute and, as a rule, two-winged, resembling small gnats, and may be bred from the male scales. The females are for the most part stationary, being fixed to the plant by the protecting, waxy, excretion or scale. The Flea-lice (_Psyllidae_) frequently produce galls, and these should always be collected with the insect architects. Some species do not produce galls, and may be collected by sweeping. The Hackberry is infested by large numbers of species of Psyllids, and these produce a great variety of interesting galls. The Aleurodidae (Fringe-scales) are delicate insects, and easily injured in the taking; they are therefore best reared from their stationary and fringed larvae and pupae, which occur on the leaves of many plants. Leaves bearing the latter should also be collected and pinned or preserved in alcohol. The Parasita, the lowest representatives of the order, may be obtained from the domestic and wild animals which they infest.

COLLECTING DIPTERA.

Most Diptera frequent flowers and may be collected with a sweeping net without much difficulty. The best season is from April to June, and the bloom of the Willow, Alder, Plum, Cherry, Dogwood, Blackberry, etc., will ordinarily yield a bountiful supply of specimens and species. Parasitic and saprophytic forms may also readily be obtained by breeding, the former as in the case of the parasitic Hymenoptera, and the latter from decaying vegetable matter and fungi. The Diptera require the most delicate treatment, and the greatest care must be exercised both in collecting and handling. A light sweep net is the best implement for collecting and the contents of the net should frequently be emptied into bottles provided with blotting paper to absorb the excess of moisture. Very small Diptera should not be killed when they can not be immediately pinned, and hairy flies should never be taken from the net with the hand, but should be handled with fine forceps. A pair of special collecting shears has been used by Lord Walsingham very successfully. It is represented in the accompanying figure, and consists of a pair of screen-covered disks, between which the fly is caught. The insect is at once pinned through the screen and may be removed and transferred to a box containing a sponge soaked in chloroform. The use of this implement is especially advisable in the case of the Bee-flies (_Bombiliidae_) and other hairy forms which are liable to be rubbed when collected in the ordinary net. The Gall-making Diptera (_Cecidomyidae_) are of little value unless accompanied with their galls, and the aim should always be to collect the galls and rear the insects rather than the keeping of specimens taken in the course of general collecting with a sweep net. The rearing of Cecidomyidae is, however, a delicate task, and requires considerable experience. Some knowledge of the habits of the species is very essential to success. From immature galls no rearings need be expected. A good plan is to examine the galls from time to time and collect them when it is found that the larvae are beginning to abandon them. In the case of species like the common Cone Gall-gnat of the Willow, the larvae of which do not leave the gall to undergo transformation in the earth, it is advisable not to gather the galls until the transformation to the pupa state takes place, which, in this species, occurs in early spring. The various leaf-mining and seed inhabiting species can be treated as in the case of the Microlepidoptera.

COLLECTING ORTHOPTERA.

The insects of this order may all be collected by the use of the sweeping net. Some of the families are attracted to light, as certain of the roaches and green locusts, or Katydids (_Locustidae_). Our common roaches (_Blattidae_) are cosmopolitan insects, and infest dwellings. Certain species are also found about ponds, under rotten logs, the bark of trees, and particularly in decaying vegetable matter. In the tropics the species are very abundant, but aside from the domestic forms, they occur rarely in northern latitudes. The collection of the egg-cases (ootheca) is important as they furnish many interesting characters. The Mantidae, of which the Preying Mantis (_Phasmomantis carolina_) is a type, are sluggish, carnivorous insects frequently found about houses and may best be collected by general sweeping of vegetation. The Phasmidae or Walking-sticks are herbivorous and may be collected in the midst of vegetation by sweeping or by the hand. The crickets (_Gryllidae_) frequent, for the most part, moist situations. Certain forms, like the Mole-cricket and the Jumping Water-crickets (_Trydactylus_ spp.), burrow in moist soil and occur in numbers near the edges of ponds and water courses. The katydids and locusts are abundant on low shrubs or trees and in pasture and meadow land, but are most numerous in the somewhat dry, arid regions of the West. Most of these insects mature in late summer and fall and should be collected at this season. The Forficulidae or Earwigs are very odd-looking insects, resembling somewhat the Rove-beetles (_Staphylinidae_), and are provided with a prominent anal forceps. They are very rare in the United States, are nocturnal in habit; and, flying about at dusk, may be attracted to light or may be secured by sweeping after nightfall. They feed on flowers and fruit.

COLLECTING NEUROPTERA.

As indicated in the preliminary outline of classification, this large order has been divided into many orders by later entomologists. It has also been divided, as indicated, into two grand divisions, the Pseudoneuroptera, comprising those insects with incomplete transformations, and the Neuroptera proper, comprising those insects whose metamorphoses are complete. It will be convenient to discuss these insects under these two heads.

_Pseudoneuroptera._--Spring-tails, Bird-lice, Stone-flies, White-ants, Dragon-flies, May-flies.

The Spring-tails, Fish-moths, etc., representing the primitive stock from which the higher forms have developed, have a varied habit and hence are to be found in divers situations. The Spring-tails (_Collembola_, etc.), occur in damp and moist places, usually in immense numbers. The Fish-moths and Book-mites are common household pests, but also occur outdoors under logs, boards, bricks, and rubbish of all sorts. In houses they feed on the starch paste beneath wall-paper and also on the starch in bookbindings and other domestic articles. They may be collected at all seasons and a sieve is the only implement necessary.

The Bird-lice or Mallophaga may be collected at all seasons on birds and mammals. A number of species infest domestic animals, horses, cattle, etc., but the majority of them can be found only by the examination of domestic fowls and wild birds. The Stone-flies (_Perlidae_) are found in the neighborhood of water courses and ponds, are very sluggish in flight, and easily captured with the sweep-net. They are also attracted to light. The Psocidae are a small family of certain degraded wingless forms, comprising the Book-lice, which, as the name implies, infest books, feeding on the starch of the binding. Others have ample wings and closely resemble large Aphides. They occur on the trunks of trees and on foliage, and feed on lichens and other dried vegetable matter. They are gregarious in habit and frequently occur in immense numbers together. In the case of the Termitidae or White-ants, their abundance renders their collection an easy matter. Effort, however, should be made to discover the different forms, the females and soldiers as well as the workers. The former may be found in rotten tree trunks, but are very rarely met with. In the tropics many species occur and construct curious nests, either attaching them to the boughs of trees or building them in the form of pyramids on the ground. The Dragon-flies (_Libellulidae_,) are collected in the same way as the Diurnal Lepidoptera. They are very swift flyers, and are practically always on the wing. Their collection requires some degree of skill in the use of the net. A good method consists in visiting, in the early morning, water courses in which the larval and pupal states are passed, and capturing the adults just as they issue from their pupal skins at the edges of the pond or stream. In cold weather they are less active and may frequently be found clinging to trees and plants, particularly in the vicinity of their breeding places. May-flies (_Ephemeridae_) occur in immense numbers near their breeding places in ponds and streams and are also attracted in large quantities to electric lights. Their collection is therefore an easy matter, but on account of the very fragile nature of these insects the utmost care must be employed in handling them. The early states of all the aquatic forms mentioned above may be obtained for breeding by the use of the dip net by dragging it forcibly against water plants.

_Neuroptera proper_ (Hellgrammites, Lace-wings, Ant-lions, Caddis-flies, etc.)--Among the largest insects of this order are the Sialidae, which includes the enormous Hellgrammite Fly, _Corydalus cornutus_. The larvae of this insect are carnivorous and occur in streams, under stones, etc. The adults may be collected in neighboring situations and are also attracted to light. The Lace-wing flies (_Chrysopa_), Ant-lions, etc., are carnivorous as larvae, and occur, the former among the Aphides which infest various plants and the latter at the bottom of pits in loose, sandy soil. The adults may be obtained by general sweeping and are also attracted to light. The most interesting insects of this order are the Caddis-flies, on account of the peculiar and frequently very beautiful cases constructed by their larvae, which it is important to collect. The Caddis-flies breed in ponds and lakes and the adults may be collected in such situations or at light. The larvae may easily be reared, and should be collected for this purpose. Most of the insects named in this order are extremely delicate and require great care in handling.

KILLING AND PRESERVING INSECTS.

Between the collecting of the specimens and their final disposition in a well-arranged cabinet, a good deal of mechanical work is necessary, involving a skill and dexterity which can be thoroughly acquired only by practice.

FIRST PRESERVATION OF LIVING SPECIMENS.--Larvae, pupae, or imagoes, intended for rearing purposes, must be kept alive, and are best placed, after capture, in tin boxes of various sizes, according to the number of specimens to be put in each and according to the size or nature of the food plant, etc., on or in which the specimens are found, and of which a quantity must always be taken home. For larger tin boxes those known as "Seidlitz powder boxes," described and figured below, which can be made to order at any tinner's shop, are well adapted, and smaller tin boxes of a convenient round form can be obtained of the watchmaker. The collector will find it advisable to take with him on his longer jaunts a larger tin collecting box as well as the smaller boxes, and for this purpose nothing is better than a good botanist's collecting can or vasculum. All tin boxes used for entomological purposes should be tight, and the cover should so fit that it neither drops off too readily nor closes too tightly. Larvae of Lepidoptera and Tenthredinidae should be placed in a box with a quantity of the leaves of the plant on which they were found. Larvae, especially of Coleoptera, found in the earth or in decayed wood, should be placed in a box filled with such earth or wood, so as to prevent shaking or rattling about. Larvae found in roots or stems of living plants can generally be reared to maturity only if the whole plant with a quantity of the surrounding soil is taken home, and for this purpose the large collecting box, just mentioned, is very useful. Most Coleopterous or other larvae found under bark or in solid wood can be reared only if large sections of the wood are obtained and the larvae are full grown or nearly so. This holds true, also, of species breeding in seeds and with most leaf-mining species. The greatest difficulty is experienced with carnivorous Coleopterous larvae, and care should be taken with such not to inclose two or more specimens in one box. Most larvae die quickly if placed in an empty box, and this is especially true of predaceous species; so that it is always advisable to pack the box with moist soil, decaying wood, leaves or other similar substance. Aquatic larvae should be carried in tin boxes filled with wet moss or some water plant, for, if placed in corked vials with water, they die quickly.

KILLING SPECIMENS.--Specimens not intended for rearing should be killed immediately after capture unless for each specimen a separate vial or box can be provided. If a number of miscellaneous insects are put in the same vial the stronger specimens will, in a short time, crush or otherwise injure the more delicate ones or the predaceous species will devour any others they can master. But even where the specimens are killed immediately the following rule should be observed: Do not put large and small specimens in the same vial, but provide a larger bottle for the larger specimens, and one, or still better, several, smaller vials for the medium-sized and very small specimens. The importance of this rule is recognized by all experienced collectors.

There are several methods of killing insects, each having its own peculiar advantages and drawbacks.

_Alcohol._--The use of alcohol will, on the whole, prove the most satisfactory method of killing Coleoptera, many Hemiptera, some Neuroptera, and larvae of all sorts. Only the best quality of alcohol should be used, but it should be diluted with from 30 to 40 per cent of pure water, the greatest care being taken to keep the alcohol as clean as possible. During the collecting a mass of debris and dirt is apt to be thrown into the bottle, and when this is the case the alcohol should be changed even during short excursions. At any rate, upon the return from the excursion, the specimens should be at once taken from the bottle and washed in pure alcohol in a shallow vessel. The larvae and other material intended for permanent preservation in alcohol should be transferred to suitable vials and the material to be mounted cleansed with chloroform or acetic ether and then prepared for the cabinet. If it is inconvenient or impossible to mount the Coleoptera, etc., soon after the return from the excursion they should be washed, dried, and placed in pill boxes between layers of soft paper, or they may be replaced in a vial with pure alcohol. On longer collecting trips, lasting several days or weeks, specimens will keep thus very well, provided they are not shaken up, and this can be prevented by filling the empty space in the vial with cotton or soft paper. If the bottle is a large one and contains many large specimens the alcohol should be renewed three or four times at intervals of eight or ten days; otherwise the specimens are liable to decompose. Small and delicate specimens, if they are to be kept in alcohol, should be treated with still greater care. Upon the return from the excursion they should also be cleaned in pure alcohol and placed in small vials into which a very few drops of alcohol, just sufficient to keep the contents moist, are poured. The vial should be corked as tightly as possible and the specimens will keep pretty well for an indefinite time.

The drawbacks to the use of alcohol are: 1st, that all hairy specimens are liable to spoil; 2ndly, that all Coleoptera with soft integuments spread the wing-cases apart if kept too long in it. The advantage of the alcohol is that it is the simplest and least troublesome fluid for naturalists traveling in distant countries who are not specialists in entomology. Specimens killed in alcohol are also less liable to be attacked by verdigris when pinned than those killed by some other method. Rum, whisky, or similar strong alcoholic liquors may be used as substitutes where no pure alcohol can be obtained, but are not especially to be recommended.

_Chloroform and Ether._--Killing with the fumes of _chloroform_ or _ether_ (sulphuric or acetic) or _benzine_, or some other etheric oil, is often practiced and advocated by those who, for any reason, dislike the use of alcohol or object, on account of its poisonous nature, to the use of cyanide of potassium, and they are of especial value in the case of butterflies and moths, Hymenoptera and Diptera. "A small and stout bottle of chloroform or ether, with a brush securely inserted into the cork (Fig. 89), will be found very serviceable. A slight moistening through the air net will stupefy most insects caught in it, and facilitate their removal to the cyanide bottle; while a touch or two with the wet brush under the head and thorax, will kill the more delicate specimens outright, without in the least injuring them. Another way of using chloroform is by means of a small, hollow tube passed through the cork, what is called jeweler's hollow wire answering the purpose. The liquid evaporates more readily in such a bottle, and I altogether prefer the first mentioned. Some large insects, and especially female moths, whose size prevents the use of the ordinary cyanide bottles, are difficult to kill. With these, fluttering may be prevented by the use of chloroform, or they may be killed by puncturing the thorax or piercing the body longitudinally, with a needle dipped in liquid cyanide, or oxalic acid. A long bottle with a needle thrust into the cork may be kept for this purpose; but the needle must be of ivory or bone, as those of metal are corroded and eaten by the liquids. * * *

"For killing small and delicate moths which have been bred, I find nothing more handy than chloroform. They may be caught in turned wooden boxes which are kept by every druggist; and a touch of the chloroform on the outside of the box immediately stupefies them. It has a tendency to stiffen them, however, and they are best set immediately after death."

A piece of heavy blotting paper or heavy cloth soaked with chloroform or ether or benzine and placed at the bottom of a jar or bottle makes an excellent killing bottle for large-sized insects. For smaller specimens the collecting vial should be half filled loosely with narrow strips of soft paper, upon which a few drops of the liquid are poured, not so much, however, as to wet the paper. While collecting, the vial must be kept closed as much as possible. Some collectors prefer chloroform, others ether. If this method of killing is practiced with the necessary care, there is no objection whatever to it; the specimens are not wetted as they are in alcohol, and remain cleaner than those killed by any other method. The drawback is that the substances mentioned evaporate very rapidly and have to be renewed even on short excursions. On account of this great volatility, one can never be certain that all the specimens in the collecting bottle are dead after a given time and there is always some danger that one or the other of the hardier insects may regain activity. What mischief such revived specimens are capable of doing, many collectors have experienced to their sorrow. Another disadvantage of these volatile substances is that if used in too large quantities they will, in delicate specimens, especially beetles, cause an extension of the soft ligaments between the head and prothorax or between the latter and the mesothorax, and thus bring the specimen into an unnatural position, or cause the head, or head and thorax to drop off.

_Cyanide of Potassium._--The method of killing which, of late years, has found most favor with collectors, is the use of cyanide of potassium. For killing large sized specimens they are simply put in what is now universally known as the "cyanide bottle." This may be constructed as follows:

Take a 2-ounce quinine bottle, or still better a shorter bottle with a wide mouth; break up a quantity of cyanide of potassium into pieces of convenient size (about a cubic centimeter); put these pieces in the bottle so that they form an even layer at the bottom; mix in a convenient vessel a quantity of plaster of Paris with water just sufficient to make the mixture semifluid and then pour it over the cyanide so as to cover this last to a depth of about 5 millimeters. The bottle is then left open for an hour or two until the plaster is thoroughly dry. The walls of the bottle are then cleansed from particles of the plaster which may have splashed on them, and the bottle is ready for use. If not used too frequently, especially in warm weather, it will last for an entire year or longer. Bottles or vials of different sizes can be prepared in the same way, and a very small cyanide vial which can be carried in the vest pocket will be found most convenient for use on all occasions. Fig. 92 represents a medium-sized chemist's test tube, converted into a very convenient cyanide bottle, in which, however, a cotton wad has been used to keep the poison in place. When the collected specimens have been removed from the bottle the latter should be carefully wiped clean with a piece of cloth or paper. The surface of the plaster soon becomes dirty and, on account of the hygroscopic property of the cyanide, more or less moist, especially during warm weather. The cyanide bottle is, therefore, not well adapted for the killing and temporary preservation of small and delicate specimens. This difficulty can be altogether obviated by placing a circular piece of blotting paper, cut to neatly fit the interior of the bottle, on the surface of the plaster. This can be renewed once a week or so, or oftener if it becomes necessary. It will frequently be advisable, also, especially in the collection of Diptera, Hymenoptera, and other delicate insects, to put a strip of blotting paper partially round the inner side of the bottle. This will absorb any moisture which may gather on the inside of the bottle and which would otherwise wet and injure the specimens. The accompanying figure (Fig. 93) illustrates a bottle arranged as described above. A similar result is attained by some collectors by partially filling the bottle with narrow strips of bibulous paper to support and separate the insects as shown at Fig. 91.

For delicate specimens, also, the collecting bottle may consist of a test-tube of about the size of Fig. 92. This is half filled with loose, thin strips of soft white paper. A piece of cyanide about the size of a pea is then wrapped carefully in paper and so placed in the middle of the strips that it can not come in contact with the sides of the glass. Some prefer to pin the paper containing the cyanide to the lower surface of the cork. The latter should be rather short and tapering toward its lower end. It is longitudinally perforated through its center by a round hole just large enough to insert a goose-quill, which is cut straight at the lower end and obliquely at its upper end. By means of this goose-quill the specimens may be introduced into the bottle without taking off the cork. This form of cyanide bottle lasts for only one day's collecting, except in cold weather, and in very warm weather it is advisable to take two prepared bottles along, so that the first used can be stowed away as soon as the cyanide begins to moisten the paper strips. Most insects are quickly killed in such a bottle, but some Coleoptera must be left in for five or six hours, while others resist death for a still longer time. This is especially true of the Coleopterous families Curculionidae, Trogositidae, and Tenebrionidae.

Submersion in alcohol will prove a satisfactory method of killing these or other beetles with similar vitality.

_Other Agents._--Prof. E. W. Claypole has found the use of benzine or gasoline very cheap and satisfactory for killing Lepidoptera, as the largest are at once killed thereby without injury to their scales. (_Can. Ent._, XIX, p. 136.) He squirts it onto the specimen within the net or in the open air by means of a druggist's dropping tube. Hot water kills rapidly and leaves the specimens in good flexible condition for mounting. The heads of large insects may be held for a few moments in the water, while smaller specimens should first be thrown into a corked bottle and the bottle submitted to heat. Where the laurel grows its bruised leaves may be used in place of cyanide; they kill less quickly. The leaves of the Laurel-cherry (_Prunus laurocerasus_), a plant commonly grown in England for screens and hedges, are also used for this purpose.

Some collectors, with indifferent olfactory sense, moisten the cork of their boxes with creosote. Its killing power lasts for several days. A few whiffs from a cigar, when nothing else is at hand, will also kill many of the more tender insects.

SPECIAL DIRECTIONS FOR DIFFERENT ORDERS.--A few brief directions for the special treatment of different orders may be given. Certain Coleoptera, notably those of the Curculionid genus Lixus, are covered with a yellowish pruinosity resembling pollen, which is of an evanescent nature, so that if the specimens are collected and killed by the ordinary methods, the pruinosity is completely lost. To preserve the natural beauty of such species it is necessary to put each specimen alive in a small vial and to kill it at once by means of a lighted match held under the vial for a few seconds. In pinning or otherwise mounting the specimen it should not be handled between the fingers.

Many Hymenoptera and Lepidoptera, especially species with yellow markings, if kept for any length of time in a cyanide bottle, will become discolored, the yellow changing to reddish, and hence such insects should not be left longer than necessary in the bottle. If care is exercised in this respect, no danger of discoloration need ordinarily be feared. The chloroform collecting bottle may be used with these insects if discoloration is anticipated. All the more delicate insects, including Hymenoptera, Diptera, the smaller Lepidoptera, and the Neuroptera, require special care in killing. Large numbers should not be thrown into a killing bottle together, and plenty of bibulous paper should be kept in the bottle to prevent moisture from accumulating and wetting and ruining the specimens. It is frequently advisable to pin Diptera, especially the hairy forms (as the Bee-flies), in the net and transfer them at once to a cigar box containing a sponge moistened with chloroform. When the collecting shears are used, the insects are always thus pinned at once, which is, in fact, the only method of securing them. This is also necessary in the case of many Lepidoptera. Delicate Neuroptera may be killed by the use of the cyanide bottle, or, preferably, placed at once in a vial of alcohol, as these insects, in many instances, cannot be kept securely if pinned or mounted. Large Lepidoptera, as the Bombycids, may be killed by pouring benzine, naphtha, or chloroform over the thorax and abdomen. These substances evaporate rapidly and do not appreciably injure the vestiture of the insects. Some collectors, in the case of butterflies, seize them dexterously between the thumb and finger, and give a sharp pinch on the sides of the thorax. This will prevent the fluttering of the insect when transferred to the cyanide bottle, and, if carefully done, the scales need not be rubbed off. It is objectionable, however, because the thorax is distorted and subsequent anatomical study interfered with, and, in the case of moths, should never be practiced, as the thorax affords important characters used in classification. Orthoptera may be killed by the use of the cyanide bottle but should be transferred at once to the vials of alcohol. If placed in a cyanide bottle, especially in the case of Locusts (_Acrididae_), they are apt to exude colored juices from the mouth, so that the specimens become soiled. Hence the use of vials of alcohol is preferable, and these insects should never be thrown into vials containing delicate insects of other orders. Plant-lice, together with the plant which they infest, should be placed at once in vials of alcohol, and specimens of the Aphides, representing all the forms present, should be mounted on slides for microscopic examination. The fixed forms of Coccids, comprising the majority of the species, require no special treatment, and the leaves, twigs, or bark on which they occur may be pinned at once and placed in the collection. The free forms are treated as in the case of plant-lice.

ENTOMOTAXY.

Under this term may be considered the preparation of insects for the cabinet.

CARE OF PINNED AND MOUNTED SPECIMENS.

_Insect Pins._--In mounting insects for the cabinet, expressly made entomological pins should be used. These come from three different sources: Klaeger pins, made by Hermann Klaeger, Berlin, Germany; Karlsbad pins, made by one or several firms in Karlsbad, Bohemia, Austria; and Vienna pins, made by Miller, Vienna, Austria.[4] These three kinds of pins have each their own slight advantages and disadvantages, so that it is difficult to say which is the best. All have the disadvantage that the pinned specimens are liable to be ruined by verdigris, and to obviate this japanned ("black") insect pins are made by Klaeger and Miller. These black pins are, however, much softer than the "white" pins, and therefore more difficult to handle. A pin of 35 millimeters in length will be found most convenient for pinning all insects excepting the larger Lepidoptera and other heavy-bodied insects, for which a longer pin may advantageously be used. According to the different degrees of fineness, the pins are numbered from No. 00 (the finest in the trade) to No. 7 or 8, but the numbers used by the different manufacturers do not correspond with each other. In experience, pins of Nos. 1, 2, 3, and 4 (Klaeger numbers) are more often needed than the others. The long pins of the finer numbers (Nos. 0 and 00) are difficult to handle in the collection and, for this reason, not to be recommended.

[4] In North America, Klaeger pins and Karlsbad pins can be obtained
through Mr. John Ackhurst, 78 Ashland Place, Brooklyn, N. Y., and
possibly also through Messrs. Blake & Co., 55 North Seventh street,
Philadelphia, Pa. The Vienna pins and the Minutien-Nadeln have to be
ordered direct through the manufacturer, Mr. Miller.

For many small insects, especially Microlepidoptera and Microdiptera, which _must_ be pinned, even the finest ordinary insect-pins are too large, and two special makes of pins are in use for this purpose. The "elbow pin" (formerly made and sold by Dr. Kuenow, of Koenigsberg, Prussia, Germany) consists of a piece of fine silver wire, pointed at one end, and with a coil loop at the other end, into which a longer pin (No. 3 or No. 4) is thrust. This pin is illustrated in Fig. 94. Still more satisfactory are the "Minutien-Nadeln" (pins for minute insects) manufactured by Mr. Miller, of Vienna, Austria, and which consist of a straight piece (about 14 mm. long) of extremely fine steel wire which is pointed at one end, and which is used in connection with a piece of pith or cork. The mode of using this pin is shown in Fig. 101. These fine and elbow pins may be obtained either "white" or japanned.

"Many English entomologists use short pins, very much like those of ordinary make, and my late friend Walsh never gave up the custom, and most vehemently opposed the use of what he ridiculed as 'long German skewers.' But the only advantage that can possibly be claimed for the short pins is that they are less apt to bend, consequently more easily stuck into the bottoms of boxes, and require less room; while, compared with the long pins, they have numerous disadvantages. Long pins admit of the very important advantage of attaching notes and labels to the specimen; render it more secure from injury when handled, and from museum pests in the cabinet; and on them several rows of carded duplicates may be fastened, one under the other, so as to economize room."

I have seen few old collections in better condition than that of the late E. Mulsant, of Lyons, France; and he used iron wire, cut slantingly, of the requisite length--a common custom in France. These wires bend so easily and have such dull points that they require much more careful manipulation than the pins, and the claim made for them that they do not verdigris would, perhaps, be offset by their rusting in moist climates or near the sea. Silver wire or silver-plated wire is also used.

_Preparation of Specimens._--Upon the return from an excursion the specimens should be prepared for the collection as soon as practicable. If they have been collected in the forenoon they should be mounted the same evening, and those collected during an afternoon or evening excursion should be mounted the following morning, or, at any rate, before they get dry and brittle. Even specimens collected in alcohol should be attended to as soon as possible.

Specimens are taken from the collecting bottle, spread out on a sheet of white blotting paper and cleaned from adhering impurities either with a soft dry brush, or, in the case of species with hard covering, by washing them with chloroform or ether or benzine where necessary. Theoretically the best way of mounting would be to pin all specimens, since the under side with its important characters then remains free for examination. Pins adapted for pinning even the smallest insects have been described above, but this pinning is such a delicate operation and requires so much time that considering the large number of small specimens that may be collected on a single short excursion it is next to impossible to carry out this method, and therefore only the larger specimens need be pinned and the smaller may be glued onto the paper points described later. If the work is done with proper care all insects can be prepared for the cabinet so that both the upper and under surface of the specimen may be examined without further manipulation.