茶园常用杀虫剂除虫菊素对非靶标生物的急性毒性研究OA

To evaluate the ecological risks of 1.5%pyrethrins emulsion,a commonly used insecticide in tea plantations,its acute toxicity to non-target organisms(Japanese quail Coturnix japonica,Italian honeybee Apis mellifera,silkworm Bombyx mori,Asian corn borer egg parasitoid Trichogramma ostriniae,and seven-spotted ladybird Coccinella septempunctata)was tested in accordance with relevant national standards.The results showed that the 7-day oral LD50 for Japanese quail was>149 mg a.i./kg bw(moderately low toxicity),while the 48-hour oral and contact LD50 for Italian honeybees were 0.382 μg a.i./bee and 0.294 μg a.i./bee(highly toxic).The 96-hour LC50 for silkworms was 0.291 mg a.i./L(extreme toxic).For natural enemies,the 24-hour LR50 for T.ostriniae was 1.82 g a.i./ha,and the 15-day LR50 for C.septempunctata was 188 g a.i./ha.Acute risk assessment indicated that pyrethrins posed unacceptable risks to honeybees,silkworms,and T.ostriniaeat,while risks to quails and ladybirds were acceptable.Despite being classified as a low-toxicity pesticide,pyrethrins exhibit high acute risks to key tea plantation biocontrol agents(T.ostriniae),pollinators(A.mellifera),and silkworms.To mitigate ecological exposure,field applications should avoid peak activity periods of natural enemies and bee foraging,with priority given to precision spraying techniques.