Bombyx mori silk only once annually. The second type is called bivoltine and is normally found in China, Japan, and Korea. The breeding process of this type takes place twice annually, a feat made possible through the slightly warmer climates and the resulting two life cycles. The polyvoltine type of mulberry silkworm can only be found in the tropics. The eggs are laid by female moths and hatch within nine to 12 days, so the resulting type can have up to eight separate life cycles throughout the year. Eggs take about 14 days to hatch into larvae, which eat continuously. They have
Flacherie Flacherie Flacherie (literally: "flaccidness") is a disease of silkworms, caused by silkworms eating infected or contaminated mulberry leaves. Flacherie infected silkworms look weak and can die from this disease. Silkworm larvae that are about to die from Flacherie are a dark brown. There are two kinds of flacherie: essentially, infectious (viral) flacherie and noninfectious ("bouffee") flacherie. Both are technically a lethal diarrhea. Bouffée flacherie is caused by heat waves ("bouffée" means "sudden heat spell" in French). Viral flacherie is ultimately caused by infection with "Bombyx mori" infectious flacherie virus (BmIFV, Iflaviridae), "Bombyx mori" densovirus (BmDNV, Parvoviridae) or "Bombyx mori" cypovirus