SILKWORM

SILKWORMThe queen of fiber.

INTRODUCTION:Silkworms are the larva of adult moths. There are many types of silkworm but the most commonly used and studied is the Bombyx mori .The commercially bred caterpillar of the domesticated silk moth Bombyx mori , which spins a cocoon around itself that is later processed to yield silk fibre.Legend has it that humans and silkworms met one fine morning in the year2640 B.C. A Chinese Empress named Hsi-Ling-Chi (various other spellings found) was strolling in her garden drinking tea when a white cocoon plopped into her cup from an overhead tree.

It probably looked something like this:

Instead of dumping it out and asking her servant for another cup of tea like any reasonable person would probably have done, she studied the cocoon. She stirred the warm tea with her finger and noticed a fine strand beginning to unravel from the fuzzy cocoon. Being a weaver, she thought of using the fiber to make cloth. She called to her servant and together they unwound the cocoon into a single long filament. Thus, the silk industry was born.

THE LIFECYCLE OF A SILKWORM

eggslarvaadult mothcocoon

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EGG:It is the first stage of a silkworms life .Female lays about300 - 400 eggs Eggs stick to leaves with gelatinous secretion Creamy yellow first, after few days they change into grayIn about18C to 25C larva hatches within 10 to 12 days.Egg laying is completed in 1-24 hours.

LARVA (silkworm): After hatching the larva is extremely hairy . It feeds on mulberry leaves and grow very quickly. After four to five days it becomes inactive.Goes through five growth stages called Instars.First instar molts. Such molting occurs four times The enzyme secreted by the silk gland comes on contact with air and becomes a hard and fine thread which is known as silk.The larval stage lasts about 27 days

PUPA(cocoon):The stage in which the larva undergoes active changes called metamorphosis. Colour can range from white to golden yellow. Second molting occurs inside the cocoon.Silk is obtained from the cocoon of the.The cooked PUPAS are eaten and in some countries.The cocoon takes about 2 - 3 weeks for to metamorphose into adult

14 days hatches inside the cocoon from its pupaskinThe adult silkworm is a.k.a a moth , are unisexual . Once out the moth dries its wings and finds a mate (or vice-versa as is often the case!), Females have enlarged abdomens(as their abdomens are full of unfertilized eggs) Males are smaller, flutter a lot and bend the end of their abdomens Fluttering behavior of males is their way to attract the females.Male dies after copulation ,female is oviparous and dies after laying eggs.

In this way silkworm completes its life cycle in 45 - 50 days .

Adult:LARVA

Economic Importance:

The silkworm industry bakes or boils the cocoon to kill the pupa, then each cocoon is reeled. This is when one continuous strand of silk is unwound from each cocoon, either by hand or by a machine. 6-8 of these strands are twisted together to create one thread of silk. Silk is a expensive product today . The cocoons of a silkworms is made up of the enzyme secreted by the silk glands of a silkworm which then turns into fine threads of silk . A single cocoon gives about 1000 m of silk . Silk is a multimillion dollar business and one of the most important exports from Asia. So many people rear silkworms for a economical benefit . Many big industries rear silkworms and are based on them for income. The art of rearing silkworm for commercial benefit is called Sericulture . It cannot be overstated in its importance to commerce, industry and fashion

Some facts about silk and silkworms - In almost 2 days a silkworm spins a single silk thread that is about 1,000 to 3,000 feet long. -The silkworm female deposits around 400 eggs at a time. - The Silkworm (Bombyx mori) Latin for silkworm of the mulberry tree") is, technically, not a worm. It is the larva or caterpillar of a moth in the family Bombicidae-Strong as steel in tensile strength, silk is the strongest natural fiber known to man-The shimmering appearance for which silk is prized comes from the fibers triangular prism-like structure which allows silk cloth to refract incoming light at different angles -A highly versatile fabric, silk has proven to be ideal for a variety of uses from formal wear to sleepwear, from parachutes to rugs, from medical sutures to prosthetic arteries. -Silkworms are no longer found in the wild. - For the business of silk the ancient Chinese had built a road through the regions of Asia which was known as silk road.

AcknowledgementI would like to acknowledge the efforts put in by our teachers for making our weekends productive and enhancing our knowledge . Our special thanks to MR. Suresh SIR Chaudhary for givining us an opportunity to make and present this presentation . And lastly we would like to thank the websites and the person who published our science book without which we could not have had completed the project .

AND LASTLY

LOVESILKWORM KEEP CALM AND