Keywords: 
• fungicide /
• Bombyx mori /
• acute toxicity /
• risk assessment

Abstract: To provide scientific basis for appropriate selection and application of pesticides in mulberry gardens as well as surrounding agricultural fields, acute toxicities of 21 commonly used fungicides to silkworm (Bombyx mori) were evaluated in the laboratory using the leaf dipping method, and the risk assessment for these fungicides was also made accordingly. The toxicity test results indicated that the 96 h-LC₅₀ values of 20% ME difenoconazole, 10% EW flusilazole, 12.5% EW myclobutanil, 12.5% WP diniconazole and 70% WP hymexazol ranged between 46.5(41.9-54.0) and 154 (124-207) mg·L -1, which were classified as middle-level toxicity, and the 96 h-LC₅₀ values of 20% WP bismerthiazol, 720 g·L -1 SC chlorothalonil, 10% EW kresoxim-methyl, 2% WG kasugamycin, 430 g·L^-1 SC tebuconazole, 400 g·L^-1 SC pyrimethanil, 40% ME propiconazol, 45% ME prochloraz, 80% WG dimethomorph, 24% SP jingangmycin, 250 g·L^-1 SC hexaconazole, 15% EW triadimefon, 70% WP difenoconazole prochloraz, 50% EC difenoconazole propiconazol, 36% EW propiconazol prochloraz and 600 g·L^-1 SC dimethomorph chlorothalonil were higher than 200 mg·L^-1, which were classified as low-level toxicity. The acute risk assessment results showed that (1) because the 96 h-LC₅₀ values of 20% WP bismerthiazol, 720 g·L^-1 SC chlorothalonil, 24% SP jingangmycin and 600 g·L^-1 SC dimethomorph chlorothalonil were higher than 2 000 mg·L^-1, no risk assessment for these four fungicides were made; (2) the acute risk of seven fungicides such as 10% EW flusilazole, 12.5% EW myclobutanil, 20% ME difenoconazole, 70% WP hymexazol, 400 g·L^-1 SC pyrimethanil, 45% ME prochloraz and 80% WG dimethomorph were high; (3) the acute risk of the other ten fungicides were intermediate. It is indicated that when fungicides are applied in or near mulberry fields, measures should be taken to reduce the risk of acute toxicity to silkworm caused by fungicides in order to avoid harm to the silk production.