^jljuJu cJxiL./^"^^^-^^ Class Y>r 51S Book ^rV]_ Copyright N" COPYRIGHT DEPOSIT. I y^ SILKWORn REARING AS A PASTIME=== (WITH SIX ILLUSTRATIONS) Dr. CECIL FRENCH, Naturalist WASHINGTON, D. C, U. S. A. COPYRIGHT 1905. BY CECIL FRENCI- Jwo Copies Hece/veu ™ 13 I9Q5 Co{j>r/aru tntry '^^. PY B. 5,F 6 f^"" 7 Silkworm Rearing as a Pastime By Dr. CECIL FRENCH, Naturalist. WASHINGTON, D. C. PREFACE '^HIS little booklet has been written as a practical guide ^ for the amateur Silkworm Culturi-t, to afford an ele- mentary course of instruction in the successful pur- suit of a most delightful and fascinatmg pastime, it is not intended for the professional sericulturist and no at- tempt has been made to treat the subject from a scientific or technical standpoint. Indeed, were I to attempt the lat- ter 1 should feel 1 were treading upon hallowed ground, for classical instruction in the industry is a matter of history, referred to by Aristotle and having its being at least four thousand five hundred years ago in China, the country in which the domestication of the insect is generally believed to have had its inception. What 1 have written here is the record of my own experience, a description of the methods by which a great amount of amusement can be had. To he professional sericulturist these methods will be open to .iticism, but the pursuit of a pastime should have no pe- cuniary benefit in view, and if I do not advocate the ob- servance of hard and fast rules and attention to minor details, it is because I wish to avoid making the pastime irksome. At the same time I should remind my rea^ that whilst the instruction here imparted applies to rearing of the domesticated silkworm on a small scale the home, there are many species of silkworms, differing from each other in certain of their habits, and the metho. of rearing advocated in the following pages is a modifica- tion of the methods practised on a large scale by the pro- fessional sericulturists. Aside from the ample reward that will be found in knowledge gained of the marvelous workings of nature and the absorbing interest that wiM be aroused, a quantity of beautiful silk can be produced which may be put to such use as bookmarkers. I remember as a boy how I used tc^ steal from my bed on the tiptoe of expectancy in the small hours of the morning to watch for the first appearance of my little brood of spinners, and later with what pleasure L presented to my mother and sisters the skeins of beautiful silk. There was no lagging of interest, for the lifetime of the little busybodies was far too brief. In houses with limited room, the raising of more than a hundred worms will prove impracticable and should not be attempted, and even this number will require an aston- ishing amount of space. CARE OF THE EGGS. ■.^he first essential is proper care of the eg-g-s. These are re- ceived either g-rouped ill clusters adheretii to paper or other ma- terial or loose like seeds in a packet. They are of a dull yrey or '^•htly erreenish tint, thougrh when first laid are yellow. Life 'thin them remains dormant from autumn of the precediiig HE EGGS— The essfs, when spread out to hatch should not be bunched as much as they appear in this picture but should be more scattered. season until about February or March according- to the climate. Under normal conditions when the temperature rises above EQ^ F. development of the embryo commences and it will be readily un- derstood that some provision must be made to protect the delicate ernbr3o from sudden climatic cliang-es and particularly to j^uard ayainst premature hatching- in the artificially heated rooms of the average house. Fortunately, most households maintain an ideal place, namely-, a refrigerator. The eggs should be placed in a small tin box in which the e are holes punctured for ventilation, and deposited in the refrigerat»,r until the time for hatching arrives. HATCHING THE EGGS. With the advent of warm weather and the appearance of vege- tal ion, pr.-parations must be made for the hatching of the brood. There is no betttr way of determining the right time than by watching for the budding of the mulberry trees. If there are uo mulberrj' trees at hand to observe, the latter part of April may be chosen in the milder climates and the earl3' part of May in more northerly regions; but, in any case, the suppl3' of food must be secured. In the large establishments proper temperature is considered a very important matter, for upon it will depend the rapidity of incubation and the regularity and percentage of hatchings Incu- bators are used just as they are in chicken hatcheries, and a tem- perature of round about 70* F. is maintained. But for parlor cult- ure the ordinarv living room temperature will suffice, though, if the nights threaten to bring about any great variation, it is. better to place the eggs where they will keep warm. Humidity is also considered an important matter just as it is in the hatching of chickens. However, I never pinned much faith on this, but no harm is done in sprinkling a little warm water in the vicinity of the eggs, or better still, in keeping a shallow dish of water near them. The eggs are set out to hatch in the light but on no account in the direct rays f the sun. If the egg^ are separatelike seeds they should be spread out in a thin layer upon sheets of blotting-paper. In about seven or eight days and sometimes even earlier (the length of time depending on temperature) the first hatchings take place. The period of incubation, when hatchings are undertaken out of season, as for instance, in the winter months, is somewhat longer, averaging three weeks. The imminence of hatching can be determined by the whitening of the eggs. Without the aid of an incubator the hatchings are always more or less irregular and ex- tend over a week. The first worms to put in an appearance aire the strong-est and all worms emerg-lnfr after Ihe fourth or fifth daj- should be destroyed as they are g-enerally weakly and not worth the trouble of rearing-. In an irreg-ular hatching, which is una- voidable without the aid of an incubator, two colonies should be formed, the earlier and better developed worms beiujr segre- g-ated into one, the more tardy ones into the other. The hatchings take place mostlj- in the earlv morning- hours, between 4 and 9 o'clock, so that he who would observe the process must be up betimes. FOOD SUPPLY If there is any one distinguishing- feature of the silkworm's life it is the remarkable capacity of this little creature to eat. The greediest hog cannot surpass it in voracity. In the active phases of its development its prime object seems to be toeatboth day and night. But we do not begrudge it this capacious appetite when we remember what it portends — the storing up of the energy- and material necessarj- for the wonderful work of silk production. In fact, the more food we can encourage the little cr ature to crowd into itK alimentary canal during its brief lifetime, the greater may we expect the yield of silk. As I have already pointed out, the food suppl3' must be secured in anticipation of the hatchings. The natural forxl of the silk- worm is the mulberry leaf. There are man vvarietiesof mulberry trees, but the best for the purpose is the White Mulberry which is to be found in many parts of the United States. However, mul- "berry leaf is not absolutely necessary for the nourishment of the silkworm, for I have raised them on lettuce leaf, which thej- will eat with relish, when, for some reason or other mulberrv leaf was not obtainable. Thej' can even be kept alive for a time on Ihe leaf of the dandylion and one or two other plants, amongst them the Osage orange, but of this latter the young and succulent leaves should not be fed But none of these substitutesenables the worm to thrive and produce the quality or quantity of silk that it does from the mulberry. Therefore, every effort should be made to ob- tain a supply of mulberry leaf. If the culturist resides in the city he must solicit the aid of some friend in the country or make ar- rangements with some nursery. Mulberry leaves can be easily sent from one point to another by mail. A fresh supply should be obtained at least once a week. The leavescan be kept fresh a few days by putting them in a jar and covering the latter with a damp cloth. But the leaves must not be allowed to pet wet or heated as such conditions are highly conducive to disease. Tlie blossoms and berries must be discarded and onl\- healthy looking- leaves provided. If leituce is used it must be Ihorong^hly dried and cut up in small pieces. How often should the worm be fed? In China feeding- opera- tions are actually undertaken ever^- half hour. In this country and in Europe it is customary in the large establish nients to adopt regular hours for feeding-, beginning very earl^v in the morning- and ending late at night. The food (leaf) is also cut up into small pieces. But for parlor culture such niceties are b.v ro means im- perative. It is possible to provide at one feeding sufficient leaf to carry each individual through the succeeding twent3'-four houis. In fact, in my bo3'hood days this scant attention was frequently all that my broods received. A safe rule is to keep pace with the creature's appetite, remembering- that it is in the early hours of the morning when its appetite is keenest, that it is most in need of a bountiful supplv of food. I have never found mincing- or chop- ping up of the leaves necessary, though this little attention is per- haps helpful to the tender worm in the first stag-e of its existence, because its sustenance is obtained from the juice of the leaf at first. THE NURSERY In what kind of rearing place should the wormsbekept ? The lid of any old cardboard box answers the ])urp<)se admirably and as the worm increases in size the box itself should be used. The top is left open and there need be no fear of any of the worms es- caping or wandering far as long as there is a supply of food within. But let the food suppU* once diminish aud out will crawl the creature in search of a more congenial environment. Several of these extemporized trays should be kept at hand for not im\y will they be needed to afford a frequent transfer to clean (juarters but the rearing space will have to be increased as the germs enlarge. Any odd shelf or window sill out of the sun's rays will suffice as a depository for the trays. A room should be selected which is not subject to draugrhts or variations of temperature but at the same time admitn of free ventilation. Living room temperature is most suitable. It need hardly be mentioned that throug-hout the life of the worm its surrounding-s must be kept as clean as possible. If ex- crement is allowed to accumulate in the bottom of the tray unhv- g-ienlc conditions are created which are a fertile source of disease. Frequent changes to clean quarters are necessarj-. To save time and labor in effecting- the daily transfer of hund- reds of worms, a device is made use of in the form of a net having- a mesh of a size suitable to the ag-e of the worm and stretched upon a wooden frame. At nig-ht time the last meal is distributed over the net and the latter is extended over the worms. During- the nig-ht the ever-hung-r3' worms, scenting- the fresh leaf, desert their stale feeding- ground and find their way up through the meshes. The entire colony is then lifted wholesale and deposited in clean quarters. But on a small scale such facilities can be dispensed with. The ver.v small worms may be picked up and moved with a (genuine) camel's hair brnsh, whilst the larger worms may be transferred with the fingers. If gentleness is observed thei e need be no fear of injuring the worms. The first change of quarters should be made about the fourth da_v. THE PHASES OF LIFE When certain stages of development are reached the silkworm undergoes a process known as '* molting," when the entire skin is shed. Four of these molts take place at intervals of a few da.vs, during which there is a suspension of activity, thus dividing the active life of the animal up into five distinct phases. First Phasb— The hatchings having taken place the newly t)orn youngsters are picked up with a camel's-hair brush and placed in the tray in which there has previously- been evenly dis- tributed a layer of finely cut up leaf. An ample supply of food being furnished, development proceeds apace until about the fifth day, when the worm is observed to lose its appetite and become sluggish. This inaction usually creates disappointment or appre- hension in the mind of the novice if he has not previously fortified Ihimself with the knowledge of what is impending. lu a few hours the worm ceases to eat altogether and appears to lose flesh, its «kin becomes shiny and it attaches itself to the stem of a leaf or other convenient point and remains motionless with its head raised. Less food is no-w required for the remainder and none at all if every worm in the colony is molting at the same time, but as this rarely happens, food must be provided for those that are in an active state. From twenty-four to fort3-eight hours are spent in ridding itself of its old skin which it does b3' crawling out for- wards. If touched during this period it shakes the forepart of its body. Second Phase — On coming' out of the molt, the worm, which has now assumed a greyish color, looks around for food. At this stage increased space must be provided and it is better to further divide up the worms, putting- all the forward ones in one tray and the backward ones in another. About the fourth day they should all be transferred ag-ain to clean quarters. The second phase lasts about five or six days when the worms again enter upon a molt. Third Phase— This is very similar to the first two and treat- ment should be along the same lines but with an increased suppiy of food, for the worms now grow very perceptibly-. In color they become much paler. About the fifth day change of quarters must be made and on the sixth or seventh we look for the third molt. Strang-elyenoug-h, this molt and the fourth phase of the creature's life are the most critical, when diseases are prone to develop. During- the chang-e it is important to keep the surroundings as dry a d clean as possible. Fourth Phase— In this phase the worm eats more than ever and large (juantities of leaf must be provided. Chang-e to clean quarters must also be made more often, and as of ten as the chang-e is made the space should be increased. I'anicular care must also be bestowed on the selection of the leaf, avoiding any that is damp or mold\'. The fourth and last molt takes place about the sixth day. Fifth Phase— This is the most interesting- of all when re- turns may be looked for. The worm now eats a prodigious quan- tity of food and g-rows astonishing-l^', and the object should be to encourage it to stuff itself to the utmost limit. Fifty worms dur- ing- this phase will eat from three to five ounces of leaves daily. Chang-e to clean quarters must now be made dail3-, and the space still further increased. In about six or seven days, sometimes long-er, the appetite beg-ins to diminish, the worm appears to shrink, and it assumes a transparent color. In two or three daj's feeding- is altogether suspended aud the worm acts in an uneasy manner, crawls aimlesslj' up and about and raises and moves its head to and fro as if seeking- something-. In realitj- it is looking- for a convenient place to spin. A corner of the box is g-enerally selected though it will sometimes wander bejond the confines of the latter, always going- upwards. Soon H beg-ins tothrow around it a loose "cobweb" of silk. At this point it must be carefully transferred to a spinning place. The best depository for this pur- pose is a paper cornucopia about five or six inches in leng-th. Each worm is provided with its own individual refuge and the cornucopias may be pinned to the wall in a row. As a rule the worm will gratefully remain where it is placed and at once pro- ceed to carry out its task. If it does not remain within its refug'e it is a sign that it is not jet readN- to spin and it should be returned to its feedinjj- (|uarters. A Colony of well-frrown Worms hard at work devouring: mulberry leaves The worm^ are too crowded in this picture. N ore space should be al- loted than is here shown. If the worm is watched in the process of spinninj"- it will be ob- served ceaselessly moving- its head to and fro in the act of running- the thread of silk backwards and forwards in an irregrular manner. Durinjr the first si.x hours an outer loose web-like structure is thrown around itself. In the ceiiler of this it then proceeds to spin around itself the compact cocoon proper. The process lasts some three days and during- this time it moves its head to and fro some 250,000 times and paj's out a half mile or more of delicate ffolden cable. An idea of the e.Ktreme delicacy of this fiber mav be Paper Cornucopia containine: a cocoon surrounded by its floss. The cor- nucopia is always intact; a hole has been cut in it in this instance in order to afford a glimPse at the cocoon. gathered from the fact that it takes from sixty to one liundred single fibers to make the thickness of ordinary sewing- silk. The silk which the creature elaborates is the product of a semi-fluid g-landular secretion which hardens on exposure to the atmosphere. It comes from the worm iu two microscopic strands which adhere firmly tog-ether. 10 Within the cocoon in the course of the next seven or eif^ht da3-s the wonn or larva underg-oes its transformation into the chrysalis stale, and during this period passes through a sort of fifth'molt. It sheds its skin and remains motionless. In from two to three weeks from the time spinning- is commenced, if it is left undis- turbed, it will have developed into a moth which will at once begin to eat its way through the cocoon at the expense of the latter. This brings us to the consideration of what to the amateur is a ver_v important matter, viz: DISPOSITION OF THE CCCCON The technical works all teach that certain of the cocoons should be set aside for propagating purposes, the finest cocoons from worms which have been the earliest to spin being selected and carefull3' laid awaj' and the moths allowed to eat their way out in a natural manner, This means, of course, that the silk from these particular cocoons cannot be utilized, for in the act of its emergence the worm necessarily destro3'S the continuit3' of the thread. The balance of the cocoons forming the main harvest are then subjected to the fumes of bisulphide of carbon or to steam for the purpose of killing the chrvsalid?s. This is done in order to prevent the moth from eating its wa3- out and destroying the silk before the latter can be reeled. It is a necessarv step where a large number of cocoons is to be dealt with and the silk cannot be reeled within the limited time prior to the tiioth's appearance. Thus, it will be seen that the professional methods entail the loss of part of the silk harvest on the one hand and a number of breeding moths on theother. Now, to the amateur this is a matter of no small concern. In an3' case his harvest of cocoons and moths wherewith to propogate his stock is limited and he wants "to get all that is coming to him." It takes the reeling of at least eight or ten cocoons to make a skein of raw silk worth having. As a matter of fact the professional method of treatment at this stage would be, for a limited number of cocoons, highly e.x- traA'agant; it would virtuall3' be throwing away part of what it has taken so much pains to produce. It is possible to utilize the silk from ever3' cocoon aud at the same time save ever3^ moth for propagating purposes, but to accomplish this it is necessary to reel the silk soon after spinning, has been completed and to care- fulU' harbor the chr3'salis in suitable surroundings where it ma3' continue to undergo transformation into its tinal phase, that of the moth. LofC. REELING THE SILK I have already noted that ittakes some seven or eight days for the worm to complete the cocoon. It can easily be ascertained when