If a wing is examined with the naked eye, or even with a lens, a clear conception of the structure of the veins can rarely be formed. Therefore it is generally necessary to remove from the wings the scales which cover them, or else bleach them. The scales may be removed mechanically by rubbing them off. They may be made transparent by the use of chemical agents. In the case of specimens which are so valuable as to forbid a resort to these methods, a clear knowledge of the structure of the veins may be formed by simply moistening them with pure benzine or chloroform, which enables the structure of the veins to be seen for a few moments.
The evaporation of these fluids is rapid, and they produce no ill effect upon the color and texture of the wings. In the case of common species, or in the case of such as are abundantly represented in the possession of the collector, and the practical destruction of one or two of which is a matter of no moment, it is easy to use the first method. The wing should be placed between two sheets of fine writing-paper which have been moistened by the breath at the points where the wing is laid, and then by lightly rubbing the finger-nail or a piece of ivory, bone, or other hard substance over the upper piece of paper, a good many of the scales may be removed. This process may be repeated until almost all of them have been taken off. This method is efficient in the case of many of the small species when they are still fresh; in the case of the larger species the scales may be removed by means of a camel"s-hair pencil such as is used by painters. The chemical method of bleaching wings is simple and inexpensive. For this purpose the wing should be dipped in alcohol and then placed in a vessel containing a bleaching solution of some sort. The best agent is a solution of chloride of lime.
After the color has been removed from the wing by the action of the chloride it should be washed in a weak solution of hydrochloric acid. It may then be cleansed in pure water and mounted upon a piece of gla.s.s, as microscopic slides are mounted, and thus preserved. When thus bleached the wing is capable of being minutely studied, and all points of its anatomy are brought clearly into view.
[Ill.u.s.tration FIG. 38.--Outline of wing, giving names of parts.]
[Ill.u.s.tration FIG. 39.--Arrangement of scales on wing of b.u.t.terfly.]
The veins in both the fore and hind wings of b.u.t.terflies may be divided into simple and compound veins. In the fore wing the simple veins are the costal, the radial, and the submedian; in the hind wing, the costal, the subcostal, the upper and lower radial, the submedian, and the internal are simple. The costal vein in the hind wing is, however, generally provided near the base with a short ascending branch which is known as the precostal vein. In addition to these simple veins there are in the fore wing two branching veins, one immediately following the costal, known as the subcostal, and the other preceding the submedian, known as the median vein. The branches of these compound veins are known as nervules. The median vein always has three nervules. The nervules of the subcostal veins branch upwardly and outwardly toward the costal margin and the apex of the fore wing. There are always from four to five subcostal nervules. In the hind wing the subcostal is simple. The median vein in the hind wing has three nervules as in the fore wing. Between the subcostal and the median veins, toward the base in both wings, is inclosed the cell, which may be wholly or partially open at its outer extremity, or closed. The veinlets which close the cell at its outward extremity are known as the discocellular veins, of which there are normally three. From the point of union of these discocellular veins go forth the radial veins known respectively as the upper and lower radials, though the upper radial in many genera is emitted from the lower margin of the subcostal.
An understanding of these terms is, however, more readily derived from a study of the figure in which the names of these parts are indicated (Fig. 40).
[Ill.u.s.tration FIG. 40.--Wing of _Anosia plexippus_, showing the names of the veins and nervules: _C_, _C_, costal veins; _SC_, subcostal vein; _SC_1_, etc., subcostal nervules; _UR_, upper radial; _LR_, lower radial; _M_, median veins; _M_1_, _M_2_, _M_3_, median nervules; _SM_, submedian veins; _I_, internal veins; _PC_, precostal nervule; _UDC_, _MDC_, _LDC_, upper, middle, and lower discocellulars.]
b.u.t.terflies generally hold their wings erect when they are at rest, with their two upper surfaces in proximity, the under surfaces alone displaying their colors to the eye. Only in a few genera of the larger b.u.t.terflies, and these tropical species, with which this book does not deal, is there an exception to this rule, save in the case of the _Hesperiidae_, or "skippers," in which very frequently, while the anterior wings are folded together, the posterior wings lie in a horizontal position.
_Internal Organs._--Thus far we have considered only the external organs of the b.u.t.terfly. The internal organs have been made the subject of close study and research by many writers, and a volume might be prepared upon this subject. It will, however, suffice for us to call the attention of the student to the princ.i.p.al facts.
[Ill.u.s.tration FIG. 41.--Longitudinal section through the larva of _Anosia plexippus_, ?, to show the internal anatomy (the Roman numerals indicate the thoracic, the Arabic the abdominal segments): _b_, brain; _sog_, suboesophageal ganglion; _nc_, nervous cord; _oe_, oesophagus; _st_, stomach; _i_, intestine; _c_, colon; _sv_, spinning-vessel of one side; _s_, spinneret; _mv_, Malpighian vessel, of which only the portions lying on the stomach are shown, and not the mult.i.tudinous convolutions on the intestine; _t_, testis; _dv_, dorsal vessel; the salivary glands are not shown. (Magnified 3 diameters.) (Burgess.)]
The muscular system finds its princ.i.p.al development in the thorax, which bears the organs of locomotion. The digestive system consists of the proboscis, which has already been described, the gullet, or oesophagus, and the stomach, over which is a large, bladder-like vessel called the food-reservoir, a sort of crop preceding the true stomach, which is a cylindrical tube; the intestine is a slender tube, varying in shape in different genera, divided into the small intestine, the colon, and the r.e.c.t.u.m. b.u.t.terflies breathe through spiracles, little oval openings on the sides of the segments of the body, branching from which inwardly are the tracheae, or bronchial tubes. The heart, which is located in the same relative position as the spine in vertebrate animals, is a tubular structure. The nervous system lies on the lower or ventral side of the body, its position being exactly the reverse of that which is found in the higher animals. It consists of nervous cords and ganglia, or nerve-knots, in the different segments. Those in the head are more largely developed than elsewhere, forming a rudimentary brain, the larger portion of which consists of two enormous optic nerves. The student who is desirous of informing himself more thoroughly and accurately as to the internal anatomy of these insects may consult with profit some of the treatises which are mentioned in the list of works dealing with the subject which is given elsewhere in this book.
[Ill.u.s.tration FIG. 42.--Longitudinal section through the imago of Anosia plexippus, ?, to show the internal anatomy: _t_, tongue; _p_, palpus; _a_, antenna; _pr_, prothorax; _mes_, mesothorax; _met_, metathorax; _ps_, pharyngeal sac; _b_, brain; _sog_, suboesophageal ganglion; 1-2, blended first and second ganglia of the larva; 3-4, blended third and fourth ganglia of the larva; _l_, _l_, _l_, the three legs; _ac_, aortal chamber; _dv_, dorsal vessel; _oe_, oesophagus; res, reservoir for air or food; _st_, stomach; _mv_, Malpighian vessels; _i_, intestine; _c_, colon; _r_, r.e.c.t.u.m; _cp_, copulatory pouch; _o_, oviduct; _ag_, accessory glands; _sp_, spermatheca; _ov_, ovaries (not fully developed); _nc_, nervous cord. (Magnified 3 diameters.) (Burgess.)]
_Polymorphism and Dimorphism._--Species of b.u.t.terflies often show great differences in the different broods which appear. The brood which emerges in the springtime from the chrysalis, which has pa.s.sed the winter under the snows, may differ very strikingly from the insect which appears in the second or summer brood; and the insects of the third or fall brood may differ again from either the spring or the summer brood.
The careful student notes these differences. Such species are called polymorphic, that is, appearing under different forms. Some species reveal a singular difference between the s.e.xes, and there may be two forms of the same s.e.x in the same species. This is most common in the case of the female b.u.t.terfly, and where there are two forms of the female or the male such a species is said to have dimorphic females or males. This phenomenon is revealed in the case of the well-known Turnus b.u.t.terfly; in the colder regions of the continent the females are yellow banded with black, like the males, but in more southern portions of the continent black females are quite common, and these dark females were once thought, before the truth was known, to const.i.tute a separate species.
_Albinism and Melanism._--Albinos, white or light-colored forms, are quite common among b.u.t.terflies, princ.i.p.ally among the females. On the other hand, melanism, or a tendency to the production of dark or even black forms, reveals itself. Melanism is rather more common in the case of the male s.e.x than in the female s.e.x. The collector and student will always endeavor, if possible, to preserve these curious _aberrations_, as they are called. We do not yet entirely understand what are the causes which are at work to produce these changes in the color, and all such aberrant specimens have interest for the scientific man.
_Monstrosities._--Curious malformations, producing monstrosities, sometimes occur among insects, as in other animals, and such malformed specimens should likewise be preserved when found. One form of malformation which is not altogether uncommon consists in an apparent confusion of s.e.xes in specimens, the wings of a male insect being attached to the body of a female, or half of an insect being male and half female.
_Mimicry._--One of the most singular and interesting facts in the animal kingdom is what has been styled mimicry. Certain colors and forms are possessed by animals which adapt them to their surroundings in such wise that they are in a greater or less degree secured from observation and attack. Or they possess forms and colors which cause them to approximate in appearance other creatures, which for some reason are feared or disliked by animals which might prey upon them, and in consequence of this resemblance enjoy partial or entire immunity. Some b.u.t.terflies, for instance, resemble dried leaves, and as they are seated upon the twigs of trees they wholly elude the eye. This ill.u.s.trates the first form of mimicry. Other b.u.t.terflies so closely approximate in form and color species which birds and other insects will not attack, because of the disagreeable juices which their bodies contain, that they are shunned by their natural enemies, in spite of the fact that they belong to groups of insects which are ordinarily greedily devoured by birds and other animals. A good ill.u.s.tration of this fact is found in the case of the Disippus b.u.t.terfly, which belongs to a group which is not specially protected, but is often the prey of insect-eating creatures. This b.u.t.terfly has a.s.sumed almost the exact color and markings of the milkweed b.u.t.terfly, _Anosia plexippus_, which is distasteful to birds, and hence enjoys peculiar freedom from the attacks of enemies. Because this adaptation of one form to another evidently serves the purpose of defense this phenomenon has been called "protective mimicry." The reader who is curious to know more about the subject will do well to consult the writings of Mr. Alfred Russel Wallace and Mr. Darwin, who have written at length upon mimicry among b.u.t.terflies. There is here a field of most interesting inquiry for the student.
_The Distribution of b.u.t.terflies._--b.u.t.terflies are found everywhere that plant life suited to the nourishment of the caterpillars is found.
There are some species which are arctic and are found in the brief summer of the cold North and upon the lofty summits of high mountains which have an arctic climate. Most of them are, however, children of the sun, and chiefly abound in the temperate and tropical regions of the earth. While the number of species which are found in the tropics vastly exceeds the number of species found in the temperate zone, it is apparently true that the number of specimens of certain species is far more numerous in temperate regions than in the tropics. Very rarely in tropical countries are great a.s.semblages of b.u.t.terflies to be seen, such as may be found in the summer months in the United States, swarming around damp places, or hovering over the fields of blooming clover or weeds. In the whole vast region extending from the Rio Grande of Texas to the arctic circle it is doubtful whether more than seven hundred species of b.u.t.terflies are found. On the continent of Europe there are only about four hundred and fifty species. The number of species of b.u.t.terflies and the number of species of birds in the United States are very nearly the same.
CHAPTER II
THE CAPTURE, PREPARATION, AND PRESERVATION OF SPECIMENS
"What hand would crush the silken-winged fly, The youngest of inconstant April"s minions, Because it cannot climb the purest sky, Where the swan sings, amid the sun"s dominions?
Not thine."
Sh.e.l.lEY.
"Do not mash your specimens!"--THE PROFESSOR.
COLLECTING APPARATUS
[Ill.u.s.tration FIG. 43.--Plan for folding net-ring: _c_, halves of ring detached; _b_, upper joint of the halves; _a_, ring set; _d_, cap of ferrule; _f_, cap of ferrule, showing screw in place; _e_, screw (Riley).]
_Nets._--In the capture of insects of all orders, and especially of b.u.t.terflies and moths, one of the most important instruments is the net.
German naturalists make use of what are known as shears (_Scheren_), which are made like gigantic scissors, having at the end two large oval rings upon which wire gauze or fine netting is stretched. With this implement, which looks like an old-fashioned candle-snuffer of colossal size, they succeed in collecting specimens without doing much injury.
Shears are, however, not much in vogue among the naturalists of other countries. The favorite instrument for the ordinary collector is the net. Nets may be made in various ways and of various materials. There are a mult.i.tude of devices which have been invented for enabling the net to be folded up so as to occupy but little s.p.a.ce when not in use. The simplest form of the net, which can be made almost anywhere, is constructed as follows: A rod--preferably of bamboo, or some other light, stiff material--is used as the handle, not more than five feet in length. Attached to this at its upper end, a loop or ring made of metal, or some moderately stiff yet flexible material, should be tied securely. Upon this there should be sewed a bag of fine netting, preferably tarletan. The bag should be quite long, not less than eighteen inches deep; the ring should be not less than a foot in diameter. Such a net can be made at a cost of but a few cents, and will be, in most cases, as efficient as any of the more expensive nets which are more carefully constructed. A good, cheap ring for a net may be made by using the bra.s.s ferrule of a fishing-rod. The ferrule should be at least three quarters of an inch in diameter. Into this insert the ends of a metal ring made by bending bra.s.s, aluminium, or iron wire into the proper form. When the ends have been inserted into the ferrule, melted solder or lead may be poured into it, and the ends of the wire forming the ring will be thus firmly secured in the ferrule. The ferrule can then be inserted into its mate placed at the end of a bamboo rod. I have commonly obtained for this purpose the last joint or b.u.t.t of a fishing-rod as the handle of a net. Such a handle can often be purchased for a small sum from a dealer in fishing-rods. It can be made very cheaply. Any kind of a stick, if not too heavy, will do. It is sometimes convenient to have it in your power to lengthen the handle of your net so as to reach objects that are at some elevation above the head, and for this purpose I have had nets made with handles capable of being lengthened by jointed extensions. In collecting in tropical countries, among tall shrubbery and undergrowth, nets thus made, capable of having their handles greatly lengthened, have often proved serviceable. One of the most successful collectors I have ever had in my employment made his net by simply bending a piece of bamboo into the form of the frame of an Indian snow-shoe, to which he attached a handle about a foot and a half in length, and to this he affixed a bag of netting. He was, however, a j.a.panese, and possessed a singular dexterity in the capture of specimens with this simple apparatus to which I myself never attained. When tarletan cannot be had, ordinary mosquito-netting will do as the material for the bag. It is, however, too coa.r.s.e in the mesh for many delicate and minute species. Very fine netting for the manufacture of the bags is made in Switzerland, and can be obtained from reputable dealers.
[Ill.u.s.tration FIG. 44.--_a_, net; _b_, ferrule to receive handle; _c_, wire hoop to be fastened in the upper end of the ferrule (Riley).]
[Ill.u.s.tration FIG. 45.--_a_, ring of metal tied with wire at _a_; _b_, ferrule; _c_, plug put in before pouring in solder (Riley).]
In order to protect and preserve the net, it is well to bind it with some thin muslin at the point where it is joined to the ring. Nets are sometimes made with a strip of muslin, about two inches wide, attached to the entire circ.u.mference of the ring, and to this strip of muslin the bag is sewed. For my part, I prefer gray or green as the color for a net. White should be avoided, as experience shows that a white net will often alarm an insect when a net of darker material will not cause it to fly before the collector is ready to bring the net down over the spot where it is settled.
_Collecting-Jars._--In killing insects various methods have been used.
In practice the most approved method is to employ a jar charged with cyanide of potash or with carbonate of ammonia. For large moths and b.u.t.terflies cyanide of potash and carbonate of ammonia serve very well, but it must be remembered that carbonate of ammonia bleaches insects which are green in color. It is well, in my judgment, to use a drop or two of chloroform in the jar charged with carbonate of ammonia, for the collection of diurnal lepidoptera. By putting a few drops of chloroform into the jar, the insect is anesthetized, and its struggles are made quickly to cease. The princ.i.p.al objection to chloroform is the fact that it induces rigidity of the thoracic muscles, which subsequently sometimes interferes with handsome setting.
[Ill.u.s.tration FIG. 46.--Cyanide-jar prepared for use: _P_, perforated cardboard; _Cy_, lumps of cyanide of potash.]
[Ill.u.s.tration FIG. 47.--Piece of paper punctured and slit for pasting over the cyanide in the collecting-jar.]
In the preparation of the poisoning-jar it is well to use a jar which has a ground-gla.s.s stopper, and the mouth of which is about three inches in diameter. This will be large enough for most specimens. The one-pound hydrate of chloral jars, provided with gla.s.s stoppers and sold by Schering, make the neatest collecting-jars that are known to the writer.
I have found it well to have such jars partly covered with leather after the fashion of a drinking-flask. An opening in the leather is left on either side, permitting an inspection of the contents of the jar. The leather protects from breakage. At the bottom of such a jar a few lumps of cyanide of potash, about the size of a filbert, should be placed.
Over this may be laid a little cotton, to prevent the lumps from rattling about loosely at the bottom of the jar. Over the cotton there is pasted a sheet of strong white paper, perforated with a mult.i.tude of holes. In securing the white paper over the cyanide, the writer has resorted to a simple method which is explained in the annexed diagram. A piece of paper is placed under the jar, and a circle the size of the inside of the jar is traced upon it. Then a disk is cut out about three quarters of an inch greater in diameter than the original circle (Fig.
47). The paper is punctured over the entire surface included within the inner line, and then, with a scissors, little gashes are made from the outer circ.u.mference inward, so as to permit of the folding up of the edge of the disk. A little gum tragacanth is then applied to these upturned edges; and it is inserted into the jar and pasted securely over the cyanide by the upturned flaps. A jar thus charged will last for a long time, if kept properly closed when not in use. Cyanide of potash has a tendency to deliquesce, or melt down in the presence of moisture, and in very humid climates or damp places, if the jar is not kept well stoppered, the cyanide will quickly become semi-fluid, the paper will become moist, and specimens placed in the jar will be injured or completely ruined. It is well, however, to bear in mind the fact that the fumes of hydrocyanic acid (prussic acid), which are active in producing the death of the insect, will not be given off in sufficient volume unless there is some small amount of moisture present in the jar; and in a very dry climate the writer has found it sometimes necessary to add a drop or two of water from time to time to the cyanide. The same method which has been described for charging a jar with cyanide of potash can be employed in charging it with carbonate of ammonia.
[Ill.u.s.tration FIG. 48.--Method of disabling a b.u.t.terfly by pinching it when in the net.]
_Field-Boxes._--In collecting b.u.t.terflies it is often possible to kill, or half kill, the specimens contained in the net by a smart pinch administered to the insect by the thumb and the first finger, the pressure being applied from without the net (Fig. 48). This mode of procedure, however, unless the operator is careful, is apt to somewhat damage the specimens. The writer prefers to hold the insect firmly between the thumb and the first finger, and apply a drop or two of chloroform from a vial which should be carried in the upper left-hand vest-pocket. The application of the chloroform will cause the insect to cease its struggles immediately, and it may then be placed in the poisoning-jar, or it may be pinned into the field-box. The field-box, which should be worn at the side, securely held in its place by a strap going over the shoulder and by another strap around the waist, may be provided with the poisoning apparatus or may be without it. In the former case the box should be of tin, and should have securely fastened in one corner some lumps of cyanide, tied in gauze.
The box should be very tight, so that when it is closed the fumes of the cyanide may be retained. The bottom should be covered with cork, upon which the specimens, as they are withdrawn from the poisoning-jar, should be pinned. It is well to bear strictly in mind that it is a mistake to continue to put one specimen after another into the poisoning-jar until it is half filled or quite filled with specimens. In walking about the field, if there are several insects in the jar at a time, they are likely to become rubbed and their beauty partially destroyed by being tossed about as the collector moves from place to place; and a large insect placed in a jar in which there are one or two smaller insects will in its death-struggles possibly injure the latter.
So, as fast as the insects are partially asphyxiated, or deprived of the power of motion, they should be removed from the poisoning-jar to the poisoning-box, where they are pinned in place and prevented from rubbing one against the other. Some collectors prefer simply to stun the insects, and then pin them into the field-box, where they are left, in whole or in part, to recover their vitality, to be subsequently put to death upon the return of the collector from the field. This mode of procedure, while undoubtedly it yields in the hands of a skilful operator the most beautiful specimens, appears to the writer to be somewhat cruel, and he does not therefore approve of it.
+--------------------------------------------------------------+ | | | EXPLANATION OF PLATE IV | | | | Reproduced, with the kind permission of Dr. S.H. Scudder, | | from "The b.u.t.terflies of New England," vol. iii, Plate 83. | | | | | | CHRYSALIDS IN COLOR AND IN OUTLINE--NYMPHALIDae | | | | 1. _Anosia plexippus._ Side view. | | 2. _Anosia plexippus._ In outline. | | 3. _Anosia plexippus._ Dorsal view. | | 4. _OEneis semidea._ | | 5. _OEneis semidea._ Dorsal view. | | 6. _Debis portlandia._ | | 7. _Satyrus nephele._ | | 8. _Satyrus nephele._ Dorsal view. | | 9. _Satyrodes canthus._ Side view. | | 10. _Neonympha phocion._ Side view. | | 11. _Neonympha phocion._ Side view. | | 12. _Basilarchia astyanax._ Side view. | | 13. _Basilarchia astyanax._ Side view. | | 14. _Basilarchia arthemis._ Side view. | | 15. _Chlorippe clyton._ Side view. | | 16. _Chlorippe clyton._ Side view. | | 17. _Chlorippe clyton._ Dorsal view. | | 18. _Basilarchia disippus._ Ventral view. | | 19. _Basilarchia disippus._ Side view. | | 20. _Basilarchia disippus._ Side view. | | 21. _Grapta interrogationis._ Dorsal view. | | 22. _Grapta interrogationis._ Side view. | | 23. _Basilarchia arthemis._ Dorsal view. | | 24. _Grapta interrogationis._ Outline of | | mesothoracic tubercle from the side. | | 25. _Grapta interrogationis._ | | 26. _Grapta interrogationis._ Outline of | | head from in front. | | 27. _Grapta comma._ Outline of head | | from in front; enlarged. | | 28. _Neonympha eurytus._ Side view. | | 29. _Grapta comma._ Outline of mesothoracic | | tubercle from the side. | | 30. _Grapta comma._ The same from | | another specimen. | | 31. _Grapta faunus._ Outline of head | | from in front. | | 32. _Grapta progne._ Outline of head | | from in front. | | 33. _Grapta faunus._ Side view. | | 34. _Grapta faunus._ Side view in outline. | | 35. _Grapta faunus._ Ventral view in | | outline. | | 36. _Vanessa j-alb.u.m._ Outline of mesothoracic | | tubercle from the side. | | 37. _Grapta progne._ Side view. | | 38. _Grapta progne._ Side view. | | 39. _Grapta comma._ Side view. | | 40. _Grapta interrogationis._ Side view. | | 41. _Grapta satyrus._ Side view. | | 42. _Grapta satyrus._ Ventral view. | | 43. Vanessa milberti. Side view. | | 44. _Vanessa j-alb.u.m._ Side view. | | 45. _Vanessa j-alb.u.m._ Ventral view. | | 46. _Grapta comma._ Side view. | | 47. _Grapta comma._ Side view. | | 48. _Grapta comma._ Dorsal view. | | 49. _Vanessa milberti._ Side view. | | 50. _Vanessa milberti._ Dorsal view. | | 51. _Vanessa antiopa._ Side view. | | 52. _Pyrameis atalanta._ Side view. | | 53. _Pyrameis atalanta._ Dorsal view. | | 54. _Pyrameis huntera._ Side view. | | 55. _Pyrameis atalanta._ Side view. | | 56. _Junonia coenia._ Side view. | | 57. _Junonia coenia._ Dorsal view. | | 58. _Vanessa antiopa._ Side view. | | 59. _Vanessa antiopa._ Dorsal view. | | 60. _Pyrameis cardui._ Side view. | | 61. _Pyrameis cardui._ Side view. | | 62. _Pyrameis cardui._ Dorsal view. | | 63. _Pyrameis huntera._ Dorsal view. | | 64. _Pyrameis huntera._ Side view, with | | nest woven before pupation. | | 65. _Junonia coenia._ Side view. | | 66. _Junonia coenia._ Side view. | | 67. _Junonia coenia._ Side view. | | | | [Ill.u.s.tration PLATE IV.] | +--------------------------------------------------------------+
_The Use of the Net._--In the use of the net the old saying is true that "practice makes perfect." The bag of the net should be sufficiently long to allow of its being completely closed when hanging from the ring on either side. It is possible to sweep into the net an insect which is fluttering through the air, and then by a turn of the hand to close the bag and to capture the specimen. When the insect has alighted upon the ground it is best to clap the net over it and then to raise the net with one hand. Very many species have the habit of flying upward. This is particularly true of the skippers, a group of very vigorous and swift-flying b.u.t.terflies. The writer prefers, if possible, to clap the net over the specimens and then to allow them to rise, and, by inserting the wide-mouthed collecting-jar below, to capture them without touching them at all with the fingers. So far as possible the fingers should not be allowed to come in contact with specimens, whether in or out of the net, though some persons acquire an extremely delicate yet firm touch which enables them to handle the wings of frail species without removing any of the scales. Nothing is more unsightly in a collection than specimens that have been caught and rubbed by the fingers.
_Baits._--Moths are frequently taken by the method of collecting known as "sugaring." But it may also be employed for b.u.t.terflies. For this purpose a mixture of beer and cheap brown sugar may be used. If the beer be stale drippings, so much the better. In fact, it is well, if the collector intends to remain in one locality for some time, to make a mixture of beer and sugar some hours or a day in advance of its application. In semi-tropical countries a mixture of beer and sugar is hardly as good as a mixture of mola.s.ses and water into which a few tablespoonfuls of Jamaica rum have been put. A mixture thus prepared seems to attract more effectually than the first prescription. Having provided a pail with a quart or two of the mixture, the collector resorts to the point where he proposes to carry on his work. With an ordinary whitewash brush the mixture is applied to the trunks of trees, stumps, fence-rails, and other objects. It is well to apply the mixture to a series of trees and posts located on the side of a bit of woodland, or along a path through forests, if comparatively open and not too dense. The writer has rarely had success in sugaring in the depths of forests. His greatest success has always been on paths and at the edge of woods. Many beetles and other insects come to the tempting sweets, and separate jars for capturing these should be carried in the pocket.
The collector never should attempt to kill beetles in the same jar into which he is putting b.u.t.terflies. The hard, h.o.r.n.y bodies and spiny legs of beetles will make sad havoc with the delicate wings of b.u.t.terflies.
Many other baits besides this may be employed to attract insects. Some writers recommend a bait prepared by boiling dried apples and mashing them into a pulp, adding a little rum to the mixture, and applying this to the bark of trees. In tropical countries bananas, especially rotten bananas, seem to have a charm for insects. The cane-trash at sugar-mills is very attractive. If possible, it is well to obtain a quant.i.ty of this trash and scatter it along forest paths. Some insects have very peculiar appet.i.tes and are attracted by things loathsome. The ordure of carnivorous animals seems to have a special charm for some of the most magnificently colored and the rarest of tropical b.u.t.terflies. A friend of mine in Africa, who collected for me for a number of years, used to keep civet-cats, the ordure of which was collected and placed at appropriate points in the forest paths; and he was richly rewarded by obtaining many insects which were not obtained in any other way. Putrid fish have a charm for other species, and dead snakes, when rankly high, will attract still others. It may be observed that after the trees have been treated for a succession of days or nights with the sweetening mixture spoken of above, they become very productive. When collecting in j.a.pan I made it a rule to return in the morning to the spots that I had sugared for moths the evening before, and I was always amply repaid by finding mult.i.tudes of b.u.t.terflies and even a good many day-flying moths seated upon the mossy bark, feasting upon the remnants of the banquet I had provided the evening before. There is no sport--I do not except that of the angler--which is more fascinating than the sport derived by an enthusiastic entomologist from the practice of "sugaring." It is well, however, to know always where your path leads, and not to lay it out in the dusk, as the writer once did when staying at a well-known summer resort in Virginia. The path which he had chosen as the scene of operations was unfortunately laid, all unknown to himself, just in the rear of the poultry-house of a man who sold chickens to the hotel; and when he saw the dark lantern mysteriously moving about, he concluded that some one with designs upon his hens was hidden in the woods, and opened fire with a seven-shooter, thus coming very near to terminating abruptly the career of an ardent entomologist.
_Beating._--There are many species which are apparently not attracted by baits such as we have spoken of in the preceding paragraph. The collector, pa.s.sing through the grove, searches diligently with his eye and captures what he can see, but does not fail also with the end of his net-handle to tap the trunks of trees and to shake the bushes, and as the insects fly out, to note the point where they settle, and then make them his prey. It is well in this work, as in all collecting, to proceed somewhat leisurely, and to keep perfectly cool. The caricature sometimes found in newspapers of the ardent lepidopterist running like a "quarter-back" across a ten-acre lot in quest of some flying insect does not represent the truly skilful collector, whose movements are more or less stealthy and cautious.
THE BREEDING OF SPECIMENS
By breeding it is possible to obtain specimens in the most perfect condition. Bred specimens which have not had an opportunity to fly are always preferred on account of their freshness of color and perfection of form. A great many species which apparently are exceedingly rare may often be obtained in considerable numbers by the process of breeding, the caterpillar being more readily found than the perfect insect.
Although the process of breeding involves a good deal of labor and care, it affords a most delightful field for observation, and the returns are frequently of the very greatest value.