On carefully drawing out the whole body (Pl. 1, Fig. 6, as seen from above, and showing the alimentary canal ending in a blind sac; Fig. 6a, side view), which is very extensible, soft and baggy, and examining it under a high power of the microscope, we saw multitudes, at least several hundred, of very minute larvæ, like particles of dust to the naked eye, issuing in every direction from the body of the parent now torn open in places, though most of them made their exit through an opening on the under side of the head-thorax. The Stylops, being hatched while still in the body of the parent, is, therefore viviparous. She probably never lays eggs.
On the last of April, when the Mezereon was in blossom, I caught the singular looking male (Stylops Childreni, Fig. 40; a, side view; it is about one-fourth of an inch long), which was as unlike its partner as possible. I laid it under a tumbler, when the delicate insect flew and tumbled about till it died of exhaustion in a few hours.
It appears, then, that the larvæ are hatched during the middle or last of June from eggs fertilized in April. The larvæ then crawl out upon the body of the bee, on which they are transported to the nest, where they enter, according to Peck's observations, the body of the larva, on whose fatty parts they feed. Previous to changing to a pupa the larva lives with its head turned towards that of its host, but before assuming the perfect state (which they do in the late summer or autumn) it must reverse its position. The female protrudes the front part of her body between the segments of the abdomen of her host, as represented in our figure. This change, Newport thinks, takes place after the bee-host has undergone its metamorphoses, though the bee does not leave her earthen cells until the following spring. Though the male Stylops deserts his host, his wingless partner is imprisoned during her whole life within her host, and dies immediately after giving birth to her myriad (for Newport thinks she produces over two thousand) offspring.
Xenos Peckii, an allied insect, was discovered by Dr. Peck to be parasitic in the body of wasps, and there are now known to be several species of this small but curious family, Stylopidæ, which are known to live parasitically on the bodies of our wild bees and wasps. The presence of these parasites finally exhausts the host, so that the sterile female bee dies prematurely.
As in the higher animals, bees are afflicted with parasitic worms which induce disease and sometimes death. The well-known hair worm, Gordius, is an insect parasite. The adult form is about the size of a slender knitting needle, and is seen in moist soil and in pools. It lays, according to Dr. Leidy, "millions of eggs connected together in long cords." The microscopical, tadpole-shaped young penetrate into the bodies of insects frequenting damp localities. Fairly ensconced within the body of their unsuspecting host, they luxuriate on its fatty tissues, and pass through their metamorphoses into the adult form, when they desert their living house and take to the water to lay their eggs. In Europe, Siebold has described Gordius subbifurcus, which infests the drones of the Honey bee, and also other insects. Professor Siebold has also described Mermis albicans, which is a similar kind of hair worm, from two to five inches long, and whitish in color. This worm is also found, strangely enough, only in the drones, though it is the workers which frequent watery places to appease their thirst.
Thousands of insects are carried off yearly by parasitic fungi. The ravages of the Muscardine, caused by a minute fungus (Botrytris Bassiana), have threatened the extinction of silk culture in Europe, and the still more formidable disease called pebrine is thought to be of vegetable origin. Dr. Leidy mentions a fungus which must annually carry off myriads of the Seventeen Year Locust. A somewhat similar fungus, Mucor mellitophorus (Fig. 41), infests bees, filling the stomach with microscopical colorless spores, so as greatly to weaken the insect.
As there is a probability that many insects, parasites on the wild bees, may sooner or later afflict the Honey bee, and also to illustrate farther the complex nature of insect parasitism, we will for a moment look at some other bee parasites.
PARASITES OF BEES.
Among the numerous insects preying in some way upon the Humble bee are to be found other species of bees and moths, flies and beetles. Insect parasites often imitate their host: Apathus (Plate I, Fig. 1, A. Ashtoni) can scarcely be distinguished from its host, and yet it lives cuckoo-like in the cells of the Humble bee, though we know not yet how injurious it really is. Then there are Conops and Volucella, the former of which lives like Tachina and Phora within the bee's body, while the latter devours the brood. The young (Plate I, Figs. 5, 5a) of another fly allied to Anthomyia, of which the Onion fly (Fig. 42) is an example, is also not unfrequently met with. A small beetle (Plate 1. Fig. 4, Antherophagus ochraceus) is a common inmate of Humble bees' nests, and probably feeds upon the wax and pollen. We have also found several larvæ (Fig. 43) of a beetle of which we do not know the adult form. Of similar habits is probably a small moth (Nephopteryx Edmandsii, Plate I, Figs. 2; 2a, larva; Fig. 2b, chrysalis, or pupa) which undoubtedly feeds upon the waxen walls of the bee cells, and thus, like the attacks of the common bee moth (Galleria cereana, whose habits are so well known as not to detain us, must prove very prejudicial to the well being of the colony. This moth is in turn infested by an Ichneumon fly (Microgaster nephoptericis, Plate I, Figs. 3, 3a) which must prove quite destructive.
The figures of the early stages of a minute ichneumon represented on the same plate (Fig. 7, larva, and 7a, pupa, of Anthophorabia megachilis) which is parasitic on Megachile, the Leaf-cutter bee, illustrates the transformations of the Ichneumon flies, the smallest species of which yet known (and we believe the smallest insect known at all) is the Pteratomus Putnami (Pl. I, Fig. 8, wanting the hind leg), or "winged atom," which is only one-ninetieth of an inch in length, and is parasitic on Anthophorabia, itself a parasite. A species of mite (Plate I, Figs. 9; 9a, the same seen from beneath) is always to be found In humble bees' nests, but it is not thought to be specially obnoxious to the bees themselves, though several species of mites (Gamasus, etc.) are known to be parasitic on insects.
CHAPTER IV.
A FEW WORDS ABOUT MOTHS.
The butterflies and moths from their beauty and grace, have always been the favorites among amateur entomologists, and rare and costly works have been published in which their forms and gorgeous colors are represented in the best style of natural history art. We need only mention the folio volume of Madam Merian of the last century, Harris's Aurelian, the works of Cramer, Stoll, Drury, Hübner, Horsfield, Doubleday and Westwood, and Hewitson, as comprising the most luxurious and costly entomological works.
Near the close of the last century, John Abbot went from London and spent several years in Georgia, rearing the larger and more showy butterflies and moths, and painting them in the larva, chrysalis and adult, or imago stage. These drawings he sent to London to be sold. Many of them were collected by Sir James Edward Smith, and published under the title of "The Natural History of the Rarer Lepidopterous Insects of Georgia, collected from the Observations of John Abbot, with the Plants on which they Feed." (London, 1797. 2 vols., fol.) Besides these two rare volumes there are sixteen folio volumes of drawings by Abbot in the Library of the British Museum. This work is of especial interest to the American student as it illustrates the early stages of many of our butterflies and moths.
Indeed the study of insects possesses most of its interest when we observe their habits and transformations. Caterpillars are always to be found, and with a little practice are easy to raise; we would therefore advise any one desirous of beginning the study of insects to take up the butterflies and moths. They are perhaps easier to study than any other group of insects, and are more ornamental in the cabinet. As a scientific study we would recommend it to ladies as next to botany in interest and in the ease in which specimens may be collected and examined. The example of Madam Merian, and several ladies in this country who have greatly aided science by their well filled cabinets, and critical knowledge of the various species and their transformations, is an earnest of what may be expected from their followers. Though the moths are easy to study compared with the bees, flies, beetles and bugs, and dragon flies, yet many questions of great interest in philosophical entomology have been answered by our knowledge of their structure and mode of growth. The great works of Herold on the evolution of a caterpillar; of Lyonet on the anatomy of the Cossus; of Newport on that of the Sphinx; and of Siebold on the parthenogenesis of insects, are proofs that the moths have engaged the attention of some of the master minds in science.
The study of the transformations of the moths is also of great importance to one who would acquaint himself with the questions concerning the growth and metamorphoses and origin of animals. We should remember that the very words "metamorphosis" and "transformation," now so generally applied to other groups of animals and used in philosophical botany, were first suggested by those who observed that the moth and butterfly attain their maturity only by passing through wonderful changes of form and modes of life.
The knowledge of the fact that all animals pass through some sort of a metamorphosis is very recent in physiology. Moreover the fact that these morphological eras in the life of an individual animal accord most unerringly with the gradation of forms in the type of which it is a member, was the discovery of the eminent physiologist Von Baer. Up to this time the true significance of the luxuriance and diversity of larval forms had never seriously engaged the attention of systematists in entomology.
What can possibly be the meaning of all this putting on and taking off of caterpillar habiliments, or in other words, the process of moulting, with the frequent changes in ornamentation, and the seeming fastidiousness and queer fancies and strange conceits of these young and giddy insects seems hidden and mysterious to human observation. Indeed, few care to spend the time and trouble necessary to observe the insect through its transformations; and that done, if only the larva of the perfect insect can be identified and its form sketched how much was gained! A truthful and circumstantial biography, in all its relations, of a single insect has yet to be written!
We should also apply our knowledge of the larval forms of insects to the details of their classification into families and genera, constantly collating our knowledge of the early stages with the structural relations that accompany them in the perfect state.
The simple form of the caterpillar seems to be a concentration of the characters of the perfect insect, and presents easy characters by which to distinguish the minor groups; and the relative rank of the higher divisions will only be definitely settled when their forms and methods of transformation are thoroughly known. Thus, for example, in two groups of the large Attacus-like moths, which are so amply illustrated in Dr. Harris's "Treatise on Insects injurious to Vegetation"; if we take the different forms of the caterpillars of the Tau moth of Europe, which are figured by Duponchel and Godard, we find that the very young larva has four horn-like processes on the front, and four on the back part of the body. The full grown larva of the Regalis moth, of the Southern and Middle states, is very similarly ornamented. It is an embryonic form, and therefore inferior in rank to the Tau moth. Multiply these horns over the surface of the body, lessen their size, and crown them with hairs, and we have our Io moth, so destructive to corn. Now take off the hairs, elongating and thinning out the tubercles, and make up the loss by the increased size of the worm, and we have the caterpillar of our common Cecropia moth. Again, remove the naked tubercles almost wholly, smooth off the surface of the body, and contract its length, thus giving a greater convexity and angularity to the rings, and we have before us the larva of the stately Luna moth that tops this royal family. Here are certain criteria for placing these insects before our minds in the order that nature has placed them. We have certain facts for determining which of these three insects is highest and which lowest in the scale, when we see the larva of the Luna moth throwing off successively the Io and Cecropia forms to take on its own higher features. So that there is a meaning in all this shifting of insect toggery.
This is but an example of the many ways in which both pleasure and mental profit may be realized from the thoughtful study of caterpillar life.
In collecting butterflies and moths for cabinet specimens, one needs a gauze net a foot and a half deep, with the wire frame a foot in diameter; a wide-mouthed bottle containing a parcel of cyanide of potassium gummed on the side, in which to kill the moths, which should, as soon as life is extinct, be pinned in a cork-lined collecting box carried in the coat pocket. The captures should then be spread and dried on a grooved setting board, and a cabinet formed of cork-lined boxes or drawers; as a substitute for cork, frames with paper tightly stretched over them may be used, or the pith of corn-stalks or palm wood. Caterpillars should be preserved in spirits, or in glycerine with a little alcohol added.
Some persons ingeniously empty the skins and inflate them over a flame so that they may be pinned by the side of the adult.
Some of the most troublesome and noxious insects are found among the moths. I need only mention the canker worm and American tent caterpillar, and the various kinds of cut worms, as instances.
We must not, however, forget the good done by insects. They undoubtedly tend by their attacks to prevent an undue growth of vegetation. The pruning done to a tree or herb by certain insects undoubtedly causes a more healthy growth of the branches and leaves, and ultimately a greater production fruit. Again, as pollen-bearers, insects are a most powerful agency in nature. It is undoubtedly the fact that the presence, of bees in orchards increases the fruit crop, and thus the thousands of moths (though injurious as caterpillars), wild bees and other insects, that seem to live without purpose, are really, though few realize it, among the best friends and allies of man.
Moreover, insects are of great use as scavengers; such are the young or maggots of the house fly, the mosquitoes, and numerous other forms, that seem created only to vex us when in the winged state. Still a larger proportion of insects are directly beneficial from their habit of attacking injurious species, such as the ichneumons (Fig. 43, the ichneumon of the American silk worm) and certain flies (Fig. 44, Tachina); also many carnivorous species of wasps beetles and flies, dragon flies and Aphis lions (Fig. 45, the lace-winged fly; adult, larva and eggs).
Colorado Potato Beetle.
But few, however, suspect how enormous are the losses to crops in this country entailed by the attacks of the injurious species. In Europe, the subject of applied entomology has always attracted a great deal of attention. Most sumptuous works, elegant quartos prepared by naturalists known the world over, and published at government expense, together with smaller treatises, have frequently appeared; while the subject is taught in the numerous agricultural colleges and schools, especially of Germany.
In the densely populated countries of Europe, the losses occasioned by injurious insects are most severely felt, though from many causes, such as the greater abundance of their insect parasites, and the far greater care taken by the people to exterminate their insect enemies, they have not proved so destructive as in our own land.
In this connection I may quote from one of Dr. Asa Fitch's reports on the noxious insects of New York, where he says: "I find that in our wheat-fields here, the midge formed 59 per cent. of all the insects on this grain the past summer; whilst in France, the preceding summer, only 7 per cent. of the insects on wheat were of this species. In France the parasitic destroyers amounted to 85 per cent.; while in this country our parasites form only 10 per cent."
"A true knowledge of practical entomology may well be said to be in its infancy in our own country, when, as is well-known to agriculturists, the cultivation of wheat has almost been given up in New England, New York, Pennsylvania, Ohio and Virginia, from the attacks of the wheat midge, Hessian fly, joint worm, and chinch bug. According to Dr. Shimer's estimate, says Mr. Riley, in his Second Annual Report on the Injurious Insects of Missouri, which may be considered a reasonable one, in the year 1864 three-fourths of the wheat, and one-half of the corn crop were destroyed by the chinch bug throughout many extensive districts, comprising almost the entire North-West. At the annual rate of increase, according to the United States Census, in the State of Illinois, the wheat crop ought to have been about thirty millions of bushels, and the corn crop about one hundred and thirty-eight million bushels. Putting the cash value of wheat at $1.25, and that of corn at 50 cents, the cash value of the corn and wheat destroyed by this insignificant little bug, no bigger than a grain of rice, in one single State and one single year, will therefore, according to the above figures, foot up to the astounding total of over seventy-three millions of dollars!"
The imported cabbage butterfly (Pieris rapæ), recently introduced from Europe, is estimated by the Abbé Provatncher, a Canadian entomologist, to destroy annually two hundred and forty thousand dollars' worth of cabbages around Quebec. The Hessian fly, according to Dr. Fitch, destroyed fifteen million dollars' worth of wheat in New York State in one year (1854). The army worm of the North (Leucania unipuncta), which was so abundant in 1861, from New England to Kansas, was reported to have done damage that year in Eastern Massachusetts exceeding half a million of dollars. The joint worm (Isosoma hordei) alone sometimes cuts off whole fields of grain in Virginia and northward. The Colorado potato beetle is steadily moving eastward, now ravaging the fields in Indiana and Ohio, and only the forethought and ingenuity in devising means of checking its attacks, resulting from a thorough study of its habits, will deliver our wasted fields from its direful assaults.
These are the injuries done by the more abundant kinds of insects injurious to crops. We should not forget that each fruit or shade tree, garden shrub or vegetable, has a host of insects peculiar to it, and which, year after year, renew their attacks. I could enumerate upwards of fifty species of insects which prey upon cereals and grass, and as many which infest our field crops. Some thirty well known species ravage our garden vegetables. There are nearly fifty species which attack the grape vine, and their number is rapidly increasing. About seventy-five species make their annual onset upon the apple tree, and nearly an equal number may be found upon the plum, pear, peach and cherry. Among our shade trees, over fifty species infest the oak; twenty-five the elm; seventy-five the walnut, and over one hundred species of insects prey upon the pine.
Indeed, we may reasonably calculate the annual loss in our country alone, from noxious animals and the lower forms of plants, such as rust, smut and mildew, as (at a low estimate) not far from five hundred million dollars annually. Of this amount, at least one-tenth, or fifty million dollars, could probably be saved by human exertions.
To save a portion of this annual loss of food stuffs, fruits and lumber, should be the first object of farmers and gardeners. When this saving is made, farming will become a profitable and safe profession. But while a few are well informed as to the losses sustained by injurious insects, and use means to ward off their attacks, their efforts are constantly foiled by the negligence of their neighbors. As illustrated so well by the history of the incursions of the army worm and canker worm, it is only by a combination between farmers and orchardists that these and other pests can be kept under. The matter can be best reached by legislation. We have fish and game laws; why should we not have an insect law? Why should we not frame a law providing that farmers, and all owning a garden or orchard, should cooperate in taking preventive measures against injurious insects, such as early or late planting of cereals, to avert the attacks of the wheat midge and Hessian fly; the burning of stubble in the autumn and spring to destroy the joint worm; the combined use of proper remedies against the canker worm, the various cut worms, and other noxious caterpillars? A law carried out by a proper State entomological constabulary, if it may be so designated, would compel the idle and shiftless to clear their farms and gardens of noxious animals.
Among some of the injurious insects reported on by Mr. Riley, the State Entomologist of Missouri, is a new pest to the cucumber in the West, the Pickle worm (Phacellura nitidalis, Fig. 46). This is a caterpillar which bores into the cucumbers when large enough to pickle, and which is occasionally found in pickles. Three or four worms sometimes occur in a cucumber, and in the garden a single one will cause it to rot. One of the most troublesome intruders in our graperies is the Vine dresser (Chœrocampa pampinatrix, Fig. 47, larva and pupa; Fig. 48, adult), a single caterpillar of which will sometimes "strip a small vine of its leaves in a few nights," and occasionally nips off bunches of half-grown grapes.
Another caterpillar, which is sometimes so abundant as nearly to defoliate the grape vine, is the eight spotted Alypia (Fig. 49; a, larva; b, side view of a segment). This must not be confounded with the bluish larva of the Wood Nymph, Eudryas grata (Fig. 50), which differs from the Alypia caterpillar in being bluish, and in wanting the white patches on the side of the body, and the more prominent hump on the end of the body. Another moth (Psychomorpha epimenis, Fig. 51, a, larva; b, side view of a segment; c, top view of the hump), also feeds on the grape, eating the terminal buds. It is also bluish, and wants the orange bands on the side of the body. Another moth of this family is the American Procris (Acoloithus Americana, Fig. 52a, larva; b, pupa; c, cocoon; d, e, imago); a dark blue moth, with a deep orange collar, whose black and yellow caterpillar is gregarious (Fig. 53), living in companies of a dozen or more and eating the softer parts of the leaves. It is quite common in the Western and Southern States. The figure represents two separate broods of caterpillars feeding on either side of the midrib of the leaf. But if the moths are, as a rule, the enemies of our crops, there are the silk worms of the East and Southern Europe and California, which afford the means of support to multitudes of the poorer classes, and supply one of the most valuable articles of clothing. Blot out the silk worm, and we should remove one of the most important sources of national wealth, the annual revenue from the silk trade of the world amounting to $254,500,000.
Silk culture is rapidly assuming importance in California, and though the Chinese silk worm has not been successfully cultivated in the Eastern States, yet the American silk worm, Teleas Polyphemus (see frontispiece, male; Fig. 54, larva; 55, pupa; 56, cocoon), can, we are assured by Mr. Trouvelot, be made a source of profit.
This is a splendid member of the group of which the gigantic Attacus Atlas of China is a type. It is a large, fawn colored moth with a tawny tinge; the caterpillar is pale green, and is of the size indicated in the cut. Mr. Trouvelot says that of the several kinds of silk worms, the larva of the present species alone deserves attention. The cocoons of Platysamia Cecropia may be rendered of some commercial value, as the silk can be carded, but the chief objection is the difficulty of raising the larva.
"The Polyphemus worm spins a strong, dense, oval cocoon, which is closed at each end, while the silk has a very strong and glossy fibre." Mr. Trouvelot, from whose interesting account in the first volume of the "American Naturalist" we quote, says that in 1865 "not less than a million could be seen feeding in the open air upon bushes covered with a net; five acres of woodland were swarming with caterpillar life." The bushes were scrub oaks, the worms being protected by a net. After meeting with such great success Mr. Trouvelot lost all his worms by pebrine, the germs being imported in eggs received from Japan through M. Guérin-Méneville of Paris. Enough, however, was done to prove that silk raising can be carried on profitably, when due precautions are taken, as far north as Boston. As this moth extends to the tropics, it can be reared with greater facility southwards. The cocoon is strong and dense, and closed at each end, so that the thread is continuous, while the silk has a very strong and glossy fibre.
Next in value to the American silk worm, is the Ailanthus silk worm (Samia Cynthia) a species allied to our Callosamia Promethea. It originated from China, where it is cultivated, and was introduced into Italy in 1858, and thence spread into France, where it was introduced by M. Guérin-Méneville. Its silk is said to be much stronger than the fibre of cotton, and is a mean between fine wool and ordinary silk. The worm is very hardy, and can be reared in the open air both in this country and in Europe. The main drawback to its culture is the difficulty in unreeling the tough cocoon, and the shortness of the thread, the cocoon being open at one end.
The Yama-maï moth (Antheræa Yama-maï) was introduced into France from Japan in 1861. It is closely allied to the Polyphemus moth, and its caterpillar also feeds on the oak. Its silk is said to be quite brilliant, but a little coarser and not so strong as that of the Bombyx mori. The Perny silk worm is extensively cultivated by the Chinese in Manchouria, where it feeds on the oak. Its silk is coarser than that of the common silk worm, but is yet fine, strong and glossy. Bengal has furnished the Tussah moth, which lives in India on the oak and a variety of other trees. It is largely raised in French and English India, according to Nogués, and is used in the manufacture of stuffs called corahs.
The last kind of importance is the Arrhindy silk worm, from India. It has been naturalized in France and Algeria by M. Guérin-Méneville, who has done so much in the application of entomology to practical life. It is closely allied to the Cynthia or Ailanthus worm, with the same kind of silk and a similar cocoon, and feeds on the castor oil plant.
The diseases of silk worms naturally receive much attention. Like those afflicting mankind, they arise from bad air, resulting from too close confinement, bad food, and other adverse causes. The most fatal and wide-spread disease, and one which since 1854 has threatened the extermination of silk worms in Europe, is the pebrine. It is due to the presence of minute vegetable corpuscles, which attack both the worms and the eggs. It was this disease which swept off thousands of Mr. Trouvelot's Polyphemus worms, and put a sudden termination to his important experiments, the germs having been implanted in eggs of the Yama-maï moth imported from Japan by M. Guérin-Méneville, and which were probably infected as they passed through Paris. Though the disaster happened several years since, he tells us that it will be useless for him to attempt the raising of silk worms in the town where his establishment is situated, as the germs of the disease are most difficult to eradicate.
So direful in France were the ravages of this disease that two of the most advanced naturalists in France, Quatrefages and Pasteur, were commissioned by the French government to investigate the disease. Pasteur found that the infected eggs differed in appearance from the sound ones, and could thus be sorted out by aid of the microscope and destroyed. Thus these investigations, carried on year after year, and seeming to the ignorant to tend to no practical end, resulted in saving to France her silk culture. During the past year (1871) so successful has his method proved that a French scientific journal expresses the hope of the complete reestablishment and prosperity of this great industry. A single person who obtained in 1871 in his nurseries 30,000 ounces of eggs, hopes the next year to obtain 100,000 ounces, from which he expects to realize about one million dollars.
CHAPTER V.
THE CLOTHES MOTH.
For over a fortnight we once enjoyed the company of the caterpillar of a common clothes moth. It is a little pale, delicate worm (Fig. 57, magnified), about the size of a darning needle, and rather less than half an inch in length, with a pale horn-colored head, the ring next the head being of the same color. It has sixteen feet, the first six of them well developed and constantly in use to draw the slender body in and out of its case. Its head is armed with a formidable pair of jaws, with which, like a scythe, it mows its way through thick and thin.
But the case is the most remarkable feature in the history of this caterpillar. Hardly has the helpless, tiny worm broken out of the egg, previously laid in some old garment of fur or wool, or perhaps in the haircloth of a sofa, when it begins to make a shelter by cutting the woolly fibres or soft hairs into bits, which it places at each end in successive layers, and, joining them together by silken threads, constructs a cylindrical tube (Fig. 58) of thick, warm felt, lined within with the finest silk the tiny worm can spin. The case is not perfectly cylindrical, being flattened slightly in the middle, and contracted a little just before each end, both of which are always kept open. The case before us is of a stone-gray color, with a black stripe along the middle, and with rings of the same color round each opening. Had the caterpillar fed on blue or yellow cloth, the case would, of course, have been of those colors. Other cases, made by larvæ which had been eating loose cotton, were quite irregular in form, and covered loosely with bits of cotton thread, which the little tailor had not trimmed off.
Days go by. A vigorous course of dieting on its feast of wool has given stature to our hero. His case has grown uncomfortably small. Shall he leave it and make another? No housewife is more prudent and saving. Out come those scissor-jaws, and, lo! a fearful rent along each side of one end of the case. Two wedge-shaped patches mend the breach; the caterpillar retires for a moment and reappears at the other end; the scissors are once more pulled out; two rents appear, to be filled up by two more patches or gores, and our caterpillar once again breathes more freely, laughs and grows fat upon horse hair and lambs' wool. In this way he enlarges his case till he stops growing.
Early Stages of the Clothes Moth.
Our caterpillar seeming to be full-grown, and apparently out of employment, we cut the end of his case half off. Two or three days after, he had mended it from the inside, drawing the two edges together by silken threads, and, though he had not touched the outside, yet so neatly were the two parts joined together that we had to search for some time, with a lens, to find the scar.
To keep our friend busy during the cold, cheerless weather, for it was mid-winter, we next cut a third of the case entirely off. Nothing daunted, the little fellow bustled about, drew in a mass of the woolly fibres, filling up the whole mouth of his den, and began to build on afresh, and from the inside, so that the new-made portion was smaller than the rest of the case. The creature worked very slowly, and the addition was left in a rough, unfinished state.
We could easily spare these voracious little worms hairs enough to serve as food, and to afford material for the construction of their paltry cases; but that restless spirit that ever urges on all beings endowed with life and the power of motion, never forsakes the young clothes moth for a moment. He will not be forced to drag his heavy case over rough hairs and furzy wool, hence with his keen jaws he cuts his way through. Thus, the more he travels, the more mischief he does.
After taking his fill of this sort of life he changes to a chrysalid (Fig. 59), and soon appears as one of those delicate, tiny, demure moths that fly in such numbers from early in the spring until the autumn.
Very many do not recognize these moths in their perfect stage, so small are they, and vent their wrath on those great millers that fly around lamps in warm summer evenings. It need scarcely be said that these large millers are utterly guiltless of any attempts upon our wardrobes; they make their attacks in a more open form on our gardens and orchards.
We will give a more careful description of the clothes moth, which was found in its different stages June 12th in a mass of loose cotton. The larva is white, with a tolerably plump body, which tapers slightly towards the tail, while the head is much of the color of gum-copal. The rings of the body are thickened above, especially on the thoracic ones, by two transverse thickened folds. It is one-fifth of an inch long.
The body of the chrysalis, or pupa, is considerably curved, with the head smooth and rounded. The long antennæ, together with the hind legs, which are folded along the breast, reach to the tip of the hind body, on the upper surface of each ring of which is a short transverse row of minute spines, which aid the chrysalis in moving towards the mouth of its case, just before the moth appears. At first the chrysalis is whitish, but just before the exclusion of the moth becomes the color of varnish.
When about to cast its pupa skin, the skin splits open on the back, and the perfect insect glides out. The act is so quickly over with, that the observer has to look sharp to observe the different steps in the operation.
Our common clothes moth (Tinea flavifrontella, Fig. 60) is of a uniform light-buff color, with a silky iridescent lustre, the hind wings and abdomen being a little paler. The head is thickly tufted with hairs and is a little tawny, and the upper side of the densely hirsute feelers (palpi) is dusky. The wings are long and narrow, with the most beautiful and delicate long silken fringe, which increases in length towards the base of the wing.
They begin to fly in May, and last all through the season, fluttering with a noiseless, stealthy flight in our apartments, and laying their eggs in our woollens.
Successive broods of the clothes moth appear through the summer. In the autumn they cease eating, retire within their cases, and early in spring assume the chrysalis state.
There are several allied species which have much the same habits, except that they do not all construct cases, but eat carpets, clothing, articles of food, grain, etc., and objects of natural history.
Careful housewives are not much afflicted with these pests. The slovenly and thriftless are overrun with them. Early in June woollens and furs should be carefully dusted, shaken and beaten. Dr. T. W. Harris states that "powdered black pepper, strewed under the edge of carpets, is said to repel moths. Sheets of paper sprinkled with spirits of turpentine, camphor in coarse powder, leaves of tobacco, or shavings of Russia leather, should be placed among the clothes when they are laid aside for the summer; and furs and other small articles can be kept by being sewed in bags with bits of camphor wood, red cedar, or of Spanish cedar; while the cloth lining of carriages can be secured forever from the attacks of moths by being washed or sponged on both sides with a solution of the corrosive sublimate of mercury in alcohol, made just strong enough not to leave a white stain on a black feather." The moths can be most readily killed by pouring benzine among them, though its use must be much restricted from the disagreeable odor which remains. The recent experiments made with carbolic acid, however, convince us that this will soon take the place of other substances as a preventive and destroyer of noxious insects.
CHAPTER VI.
THE MOSQUITO AND ITS FRIENDS.
The subject of flies becomes of vast moment to a Pharaoh, whose ears are dinned with the buzz of myriad winged plagues, mingled with angry cries from malcontent and fly-pestered subjects; or to the summer traveller in northern lands, where they oppose a stronger barrier to his explorations than the loftiest mountains or the broadest streams; or to the African pioneer, whose cattle, his main dependence, are stung to death by the Tsetze fly; or the fariner whose eyes on the evening of a warm spring day, after a placid contemplation of his growing acres of wheat blades, suddenly detects in dismay clouds of the Wheat midge and Hessian fly hovering over their swaying tops. The subject, indeed, has in such cases a national importance, and a few words regarding the main points in the habits of flies—how they grow, how they do not grow (after assuming the winged state), and how they bite; for who has not endured the smart and sting of these dipterous Shylocks, that almost torment us out of our existence while taking their drop of our heart's blood—may be welcome to our readers.
The Mosquito will be our first choice. As she leaps off from her light bark, the cast chrysalis skin of her early life beneath the waters, and sails away in the sunlight, her velvety wings fringed with silken hairs, and her neatly bodiced trim figure (though her nose is rather salient, considering that it is half as long as her entire body), present a beauty and grace of form and movement quite unsurpassed by her dipterous allies. She draws near and softly alights upon the hand of the charmed beholder, subdues her trumpeting notes, folds her wings noiselessly upon her back, daintily sets down one foot after the other, and with an eagerness chastened by the most refined delicacy for the feelings of her victim, and with the air of Velpeau redivivus, drives through crushed and bleeding capillaries, shrinking nerves and injured tissues, a many-bladed lancet of marvellous fineness, of wonderful complexity and fitness. While engorging herself with our blood, we will examine under the microscope the mosquito's mouth. The head (Fig. 61) is rounded, with the two eyes occupying a large part of the surface, and nearly meeting on the top of the head. Out of the forehead, so to speak, grow the long, delicate, hairy antennm (a), and just below arises the long beak which consists of the bristle-like maxillæ (mx, with their palpi, mp) and mandibles (m), and the single hair-like labrum, these five bristle-like organs being laid in the hollowed labium (l). Thus massed into a single awl-like beak, the mosquito, without any apparent effort, thrusts them all except the labium into the flesh. Her hind body may be seen tilling with the red blood, until it cries quits, and the insect withdraws its sting and flies sluggishly away. In a moment the wounded parts itch slightly, though a very robust person may not notice the irritation, or a more delicate individual if asleep; though if weakened by disease, or if stung in a highly vascular and sensitive part, such as the eyelid, the bite becomes really a serious matter. Multiply the mosquito a thousand fold, and one flees their attacks and avoids their haunts as he would a nest of hornets. Early in spring the larva (Fig. 62, A) of the mosquito may be found in pools and ditches. It remains at the bottom feeding upon decaying matter (thus acting as a scavenger, and in this state doing great benefit in clearing swamps of miasms), until it rises to the surface for air, which it inhales through a single respiratory tube (c) situated near the tail. When about to transform into the pupa state, it contracts and enlarges anteriorly near the middle, the larval skin is thrown off, and the insect appears in quite a different form (Fig. 62, a). The head and thorax are massed together, the rudiments of the mouth parts and of the wings and legs being folded upon the breast, while there are two breathing tubes (d) situated upon the back instead of the tail, which ends in two broad paddles (a); so that it comes to the surface, head foremost instead of tail first, a position according better with its increased age and experience in pond life. In a few days the pupa skin is cast; the insect, availing itself of its old habiliments as a raft upon which to float while its body is drying, grows lighter, and its wings expand for its marriage flight. The males are beautiful, both physically and morally, as they do not bite; their manners are more retiring than those of their stronger minded partners, as they rarely enter our dwellings, and live unnoticed in the woods. They may be easily distinguished from the females by their long maxillary palpi, and their thick, bushy, feathered antennæ. The female lays her elongated, oval eggs in a boat-shaped mass, which floats on the water. A mosquito lives three or four weeks in the water before changing to the adult or winged stage. How many days they live in the latter state we do not know.