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 directions in a domesticated environment. Consequently, the two silkmoths have been united as subspecies of a single species; in this case the name "Bombyx mori" which was published first applies for both. However, today it is usually recognized that the domesticated silkmoth is entirely dependent on human care for its survival and thus has a level of reproductive isolation from its wild relatives. 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