Bombyx mori breeding. Silkworm breeding is aimed at the overall improvement of silkworm from a commercial point of view. The major objectives are improving fecundity (the egg-laying capacity of a breed), the health of larvae, quantity of cocoon and silk production, and disease resistance. Healthy larvae lead to a healthy cocoon crop. Health is dependent on factors such as better pupation rate, fewer dead larvae in the mountage, shorter larval duration (shorter larval duration lessens the chance of infection) and bluish-tinged fifth-instar larvae (which are healthier than the reddish-brown ones). Quantity of cocoon and silk produced are directly related to the pupation
Bombyx mandarina Bombyx mandarina Bombyx mandarina, the wild silkmoth, is an insect from the moth family Bombycidae. It is the closest relative of "Bombyx mori" the domesticated silkmoth or "silkworm" (properly, this refers to the caterpillars only). Unlike the domesticated relative which is unable to fly or indeed persist outside human care, the wild silkmoth is a fairly ordinary lepidopteran. Its main difference from the domesticated taxon is the more slender body with well-developed wings in males, and the dull greyish-brown colour. "Bombyx mandarina" and the domesticated "Bombyx mori" constitute two of the currently identified eight species of the genus "Bombyx", the