50%氟啶虫胺腈水分散粒剂对家蚕的毒性评价

Toxicity Evaluation of 50% Sulfoxaflor Water Dispersible Granules to Silkworm Bombyx mori

50%氟啶虫胺腈水分散粒剂对家蚕3龄起蚕的急性食下毒性(LC_(50))为111.6599 mg/L,对家蚕具有中等毒性;50%氟啶虫胺腈水分散粒剂防治稻飞虱的推荐使用浓度2000倍(250 mg/L)与LC_(50)的毒性比为2.24,对养蚕生产有高风险性。50%氟啶虫胺腈水分散粒剂100倍稀释药液对家蚕2龄起蚕无熏蒸毒性。50%氟啶虫胺腈水分散粒剂1000倍、2000倍和4000倍在桑叶上的残毒期分别为19 d、15 d和9 d。50%氟啶虫胺腈水分散粒剂1000倍和2000倍稀释药液可通过桑叶内吸向上传导,但对家蚕的毒性远低于直接喷洒的桑叶。氟啶虫胺腈对家蚕的中毒症状主要表现为胸部膨大、摇头、吐液、爬动等。

The acute ingestive toxicity(LC50) of 50% sulfoxaflor water dispersible granules to the third instar silkworm is 111.6599 mg/L, which is moderately toxic to the silkworm, and the recommended concentration of 50% sulfoxaflor water dispersible granules to control rice planthopper is 2000 times(250 mg/L) and the toxicity ratio of LC50 is 2.24, which has a high risk to silkworm. 100 times diluted liquid of 50% sulfoxaflor water dispersible granule had no fumigating toxicity on silkworm larvae at 2 nd instar. The residual toxicity periods of 50% sulfoxaflor water dispersible granules by 1000, 2000 and 4000 times on mulberry leaves were 19, 15 and 9 days, respectively. The diluted solution of 50%sulfoxaflor water dispersible granule by 1000 times and 2000 times can be carried upward through the absorption of mulberry leaves, but its toxicity to silkworm is much lower than that of directly sprayed mulberry leaves. The poisoning symptoms of silkworm were mainly manifested by chest enlargement, shaking head, spitting and crawling.