油菜蚜虫防治用药对蜜蜂的急性毒性与风险评价

Acute Toxicity and Risk Assessment of Nine Insecticides to Honeybees in Oilseed Rape Fields

为评价油菜蚜虫防治用药对蜜蜂的影响,测定了9种常用于防治油菜蚜虫的杀虫剂对意大利蜜蜂(Apis mellifera)的急性毒性,并采用商值法开展喷施场景下的蜜蜂风险评价。结果显示,70%吡虫啉水分散粒剂(以有效成分质量分数计,下同)、10%烯啶虫胺水剂、25%噻虫嗪悬浮剂、5%丁硫克百威乳油和2. 5%溴氰菊酯乳油对蜜蜂均为高毒,但对蜜蜂的风险水平却不尽相同,其中25%噻虫嗪悬浮剂、70%吡虫啉水分散粒剂、10%烯啶虫胺水剂和2. 5%溴氰菊酯乳油对蜜蜂的风险不可接受,5%丁硫克百威乳油可通过减少用量来降低对蜜蜂的风险;50%抗蚜威可湿性粉剂对蜜蜂经口和接触毒性等级分别为中毒和低毒,也需要通过减少用量来降低对蜜蜂的风险;5%啶虫脒乳油、48%噻虫啉悬浮剂和25%吡蚜酮悬浮剂对蜜蜂的毒性等级分别为中毒、低毒和低毒,风险可接受。因此油菜蚜虫防治可优先选用对蜜蜂风险性低的品种(噻虫啉、吡蚜酮),建议施用其他杀虫剂时避开养蜂区和蜜源期,降低对蜜蜂的毒性风险。

Insecticides are used for the controlling of aphids in oilseed rape fields. To evaluate the effects of insecticides on honeybees(Apis mellifera)in oilseed rape fields,acute toxicities of 9 insecticides were tested. Meanwhile,risk assessment was carried out by risk quotients(RQ)method when the 9 insecticides were applied by spraying. The results showed that:the toxicity levels of 70% imidacridine WG,10% dimethylamine AS,25% thiazolazine SC,5% dithiocarba- mate GF and 2. 5% deltamethrin EC to honeybees were all at high class. However,the risk levels were different,and the risk of 25% thiazolazine SC,70% imidacridine WG,10% dimethylamine AS and 2. 5% deltamethrin EC were unacceptable to honeybees. The risk of 5% dithiocarbamate GF to honeybees could be reduced by decreasing the amount and frequency of use. The oral and contact toxicity of 50% pirimicarb WP were moderate and low to honeybees,respectively, and the risk could also be reduced by decreasing the amount and frequency of use. The toxicity levels of 5% acetamiprid EC,48% thiacloprid SC and 25% pymetrozine SC to honeybees were moderate,low and low,respectively. The risk levels of those insecticides are acceptable. The insecticides with low-risk to honeybees such as thiacloprid and pymetrozine could be priority to control the aphids in oilseed rape fields. In order to decrease the hazard of insecticides on honeybees, it is recommended to avoid using insecticides with high-risk in beekeeping areas and in blooming period of honey source crops.