and the pupae cut through the cocoon and emerge into adult moth. On the basis of the moults which they undergo during their larval life, B. mori is divided into three races – tri-moulters, tetra- moulters and penta- moulters. Based on voltinism (the number of broods raised per year), three kinds of races are recognized in mulberry silkworm – univoltines (one brood only), bivoltines (two broods only) and multivoltines (more than two broods).
Cultivation of food plants for the silkworms The first component, is to grow the food plants for the silkworms. Mulberry leaves India has the distinction of producing all the four types of silk i.e. (a) Mulberry silk ( . %); (b) Tasar silk ( .
%); (c) Eri silk ( . %); and (d) Muga silk ( . %) which are produced by different species of silkworms. Name the species that produces large amount and least amount of silk in India.
Figure . Life cycle of Bombyx mori XI Std Biology-Zoology Chapter- are widely used as food for silkworm Bombyx mori and the cultivation of mulberry is called as Moriculture . Presently improved mulberry varieties like Victory1, S36, G2 and G4 which can withstand various agro - climatic and soil conditions are used for planting. The favourable season for cultivating of the mulberry plants is June, July, November and December.
The mulberry crop production technology includes land preparation, preparation of cutting, planting techniques, maintenance of mulberry nursery, disease and pest management and uprooting for raising new mulberry gardens. Mulberry is also being grown as tree plant at an height of - cm with x cm or x cm spacing to harvest better silkworm cocoon crops. Rearing of silkworms The second component is the rearing of silkworm. A typical rearing house (6m x 4m x .5m) is constructed on an elevated place under shade to accommodate dfls (disease free layings).
Space of 1m should be provided surrounding the rearing house. Sufficient windows and ventilators should be provided for free circulation of air inside the rearing house. The windows and ventilators should be covered with nylon net