新烟碱类杀虫剂对蜜蜂的急性毒性及风险评价

为新烟碱类杀虫剂合理使用提供科学依据,本研究采用饲喂法和点滴法测定了9种新烟碱类杀虫剂对蜜蜂的急性毒性效应,且根据风险商值法进行了风险评价,氟啶虫酰胺和吡蚜酮作为对照药剂。试验结果表明:6种新烟碱类杀虫剂(噻虫胺、呋虫胺、吡虫啉、烯啶虫胺、氟啶虫胺腈和噻虫嗪)对蜜蜂经口和接触毒性的48 h-LD50值为1.73×10-3(1.37×10-3~2.45×10-3)~35.3×10-2(30.5×10-2~41.4×10-2)μg·蜂-1,均属于高毒级;其次为氯噻啉,该药剂对蜜蜂经口和接触毒性的48 h-LD50值为56.4×10-2(40.9×10-2~95.5×10-2)和2.05(1.13~3.18)μg·蜂-1,分别为高毒和中毒;而啶虫脒和噻虫啉对蜜蜂经口和接触毒性的48 hLD50值为2.57(1.94~3.75)~9.85(8.23~11.6)μg·蜂-1,为中毒级。对照药剂氟啶虫酰胺和吡蚜酮对蜜蜂经口和接触毒性的48h-LD50值均100μg·蜂-1,为低毒级。风险评价结果表明:噻虫胺、呋虫胺、吡虫啉、噻虫嗪、氯噻啉、烯啶虫胺和氟啶虫胺腈对蜜蜂具有不可接受的风险,啶虫脒、噻虫啉和对照药剂氟啶虫酰胺、吡蚜酮对蜜蜂的风险可接受。因此,在害虫综合治理中,应谨慎使用新烟碱类杀虫剂,以免对蜜蜂产生严重的毒副作用。

Acute Toxicity and Risk Assessment of Neonicotinoid Insecticides to Honeybees (Apis mellifera L.)

To establish a scientific basis for the rational use of neonicotinoid insecticides, the acute toxicities of nine neonicotinoid insecticides to honeybees were determined by feeding and dripping methods, and the risk assess-ment was also performed according to the risk quotient method. Flonicamid and pymetrozine were used as refer-ence substances. Results from 48-h oral and contact toxicities indicated that six neonicotinoid insecticides (clothian-idin, dinotefuran, imidacloprid, nitenpyram, sulfoxaflor and thiamethoxam) were highly toxic to honeybees with LD50 values ranging from 1.73×10-3(1.37×10-3-2.45×10-3) to 35.3×10-2(30.5×10-2-41.4×10-2)μg· bee-1, followed by imidaclothiz that were highly and moderately toxic to honeybees with LD50 values of 56.4×10-2(40.9×10-2-95.5 ×10-2) and 2.05 (1.13-3.18)μg·bee-1, while acetamiprid and thiacloprid were moderately toxic to honeybees with LD50 values ranging from 2.57 (1.94-3.75) to 9.85 (8.23-11.6)μg·bee-1. In contrast, the reference pesticides flonic-amid and pymetrozine exhibited low toxicity to the insects with LD50 values>100μg·bee-1. Results of risk assess-ment showed that clothianidin, dinotefuran, imidacloprid, thiamethoxam, imidaclothiz, nitenpyram and sulfoxaflor were classified with unacceptable risk, while acetamiprid, thiacloprid and reference substances (flonicamid and py-metrozine) were classified as acceptable risk to honeybees. Therefore, the use of neonicotinoids, should be carefully evaluated by integrated pest management (IPM) programs in order to avoid serious damages to honeybees.