RSF is produced by chemically dissolving silkworm cocoons, leaving their molecular structure intact. Lefty makes a living selling silkworm cocoons harvested by his sister, Desdemona. To prevent this, silkworm cocoons are boiled. Chinese sources claim the existence of a machine to unwind silkworm cocoons in 1090. In captivity, they eat crickets, mealworms, waxworms and silkworm larvae. Diapause hormone regulates embryonic diapause in the eggs of the silkworm moth, "Bombyx mori". Silk is a fibre produced by the silkworm in production of its cocoon. Silk, taken from the cocoon of a silkworm, is a filament. Silks from "Bombyx mori", a kind of cultivated silkworm, are the most widely investigated silks. The species was identified as "Bombyx mori", the domesticated silkworm. The silk industry is based on the silkworm caterpillar. Embiopterans produce a silk thread similar to that produced by the silkworm, "Bombyx mori". The polyvoltine type of mulberry silkworm can only be found in the tropics. The transhumance is motivated by agricultural activities (historically by the mulberry silkworm culture). Yevlakh is also engaged in poultry farming and silkworm breeding.