(also called wilt disease), a viral disease of mulberry leaf-feeding and oak leaf-feeding silkworms. The secondary causative agents of flacherie are such bacteria as Bacillus cereus. Infection occurs through the feed. The causative agents are disseminated by flies, as well as by neglect of proper hygienic measures in caring for the silkworms. The disease is highly infectious, with a high rate of mortality. The excrement of infected caterpillars is foul-smelling and liquid; their bodies darken and become flaccid, and death occurs in two or three days.

Treatment consists in dusting the feed with antibiotics. Flacherie is prevented by disinfecting the silkworm ova with a 2–3-percent solution of Formalin and by disinfecting with a hot alkaline solution the places where the caterpillars are reared and the implements used in their care.