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The silkworm is the larva or caterpillar of the domesticated silkmoth, ''Bombyx mori'' (Latin: "silkworm of the mulberry tree"). It is an economically important insect, being a primary producer of silk. A silkworm's preferred food is white mulberry leaves (monophagous). Domestic silk moths are closely dependent on humans for reproduction, as a result of millennia of selective breeding. Wild silk moths are different (having not been selectively bred) from their domestic cousins; they are not commercially viable in the production of silk. Sericulture, the practice of breeding silkworms for the production of raw silk, has been under way for at least 5,000 years in China, from where it spread to Korea and Japan, India and later the West. The silkworm was domesticated from the wild silkmoth ''Bombyx mandarina'', which has a range from northern India to northern China, Korea, Japan, and the far eastern regions of Russia. The domesticated silkworm derives from Chinese rather than Japanese or Korean stock. Silkworms were unlikely to have been domestically bred before the Neolithic age; before then, the tools required to facilitate the manufacturing of larger quantities of silk thread had not been developed. The domesticated ''B. mori'' and the wild ''B. mandarina'' can still breed and sometimes produce hybrids. == Types == Mulberry silkworms can be categorized into three different but connected groups or types. The major groups of silkworms fall under the univoltine ('uni-'=one, 'voltine'=brood frequency) and bivoltine categories. The univoltine breed is generally linked with the geographical area within greater Europe. The eggs of this type hibernate during winter due to the cold climate, and cross-fertilize only by spring, generating silk only once annually. The second type is called bivoltine and is normally found in China, Japan, and Korea. The breeding process of this type takes place twice annually, a feat made possible through the slightly warmer climates and the resulting two lifecycles. The polyvoltine type of mulberry silkworm can only be located in the tropics. The eggs are laid by female moths and hatch within nine to 12 days, so the resulting type can have up to eight separate lifecycles throughout the year. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「bombyx mori」の詳細全文を読む スポンサード リンク
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