to restrict the entry of uzi flies and other insects. Apart from the specified area of the rearing house; the following appliances such as hygrometer, power sprayers, rearing stands, foam pads, wax coated paraffin papers, nylon nets, baskets for keeping leaves, gunny bags, rotary or bamboo mountages and drier are needed for effective rearing of silkworms. The steps involved in rearing process of silkworm are disinfection of rearing house, incubation of eggs, brushing, young larval rearing and late age larval rearing. The selected healthy silk moths are allowed to mate for hours.
Female moth is then kept in a dark plastic bed, it lays about eggs in hours; the female is taken out, crushed and examined for any disease, only certified disease-free eggs are reared for industrial purpose. The eggs are incubated in an incubator. The small larvae (caterpillars) hatch between - days. These larvae are kept in trays inside a rearing house at a temperature of about °C - °C.
These are first fed on chopped mulberry leaves. After - days fresh leaves are provided. As the larvae grow, they are transferred to fresh leaves on clean trays, when fully grown they spin cocoons. Their maturity is achieved in about days.
At this stage the salivary glands (silk glands) starts secreting silk to spin cocoons. Post cocoon processing The method of obtaining silk thread from the cocoon is known as post cocoon processing. This includes stifling and reeling. The process of killing the cocoons is called stifling.
The process of removing the threads from the killed cocoon is called reeling. For reeling silk the cocoons are gathered about - days after spinning had begun. The cocoons are first treated by steam or dry heat to kill the insect inside. This is necessary to prevent the destruction of the continuous fibre by the emergence of the moth.
The cocoons are then soaked in hot water ( ° - °C) for - minutes to soften the gum that binds the silk threads together. This process is called cooking. The “cooked” cocoons XI Std Biology-Zoology Chapter-