摘要:
为明确4种烟嘧磺隆复配除草剂对意大利蜜蜂和玉米螟赤眼蜂的急性毒性影响并评估其初级风险。采用饲喂法、点滴法和玻璃管药膜法,分别测定了8%烟嘧·氯吡嘧磺隆、16%烟嘧·硝磺·氯吡嘧磺隆、36%烟嘧·莠去津和22%烟嘧·氯吡·氯氟吡氧乙酸异辛酯对意大利蜜蜂成年工蜂和玉米螟赤眼蜂的急性毒性,并分别采用危害商值和安全系数进行初级风险评估。结果表明,上述4种制剂对意大利蜜蜂成年工蜂的经口毒性48 h-LD50(半致死剂量,median lethal dose)分别为68.03、1.60×102、1.40×102和>100 μg a.i.·蜂-1,接触毒性48 h-LD50分别为18.53、53.01、89.98和>100 μg a.i.·蜂-1,危害商值均小于50,对意大利蜜蜂均为低毒且低风险。4种制剂对玉米螟赤眼蜂的急性毒性24 h-LR50(半致死用量,median lethal rate)分别为1.88×10-4、5.46×10-4、2.12×10-3和1.68×10-3 mg a.i.·cm-2,安全系数分别为0.16、0.23、0.59和0.51,其中8%烟嘧·氯吡嘧磺隆和16%烟嘧·硝磺·氯吡嘧磺隆对玉米螟赤眼蜂为高风险性,36%烟嘧·莠去津和22%烟嘧·氯吡·氯氟吡氧乙酸异辛酯为中等风险性。因此,这4种复配制剂对蜜蜂成年工蜂的风险性较低,但对赤眼蜂的风险性较高,所以在喷洒防除期间应与赤眼蜂释放期错开。
Abstract:
To evaluate the acute toxicity and risk of four multi-combination nicosulfurons, including 8% nicosulfuron·halosulfuron-methyl OD, 16% nicosulfuron·mesotrione·halosulfuron-methyl OD, 36% nicosulfuron·atrazine OD and 22% nicosulfuron·halosulfuron-methyl·fluroxypyr-meptyl OD, the acute toxicity of the herbicides to Apis mellifera and Trichogramma ostriniae were tested using oral-feeding and topical application on A. mellifera, and film bioassay on T. ostriniae. The first-tier risk assessment was evaluated by hazard quotients (HQ) for A. mellifera and risk quotients (RQ) for T. ostriniae. The results showed that the 48 h-LD50(median lethal dose) values of acute oral toxicity to A. mellifera were 68.03, 1.60×102, 1.40×102 and >100 μg a.i.·bee-1, respectively, and the 48 h-LD50 values of acute contact toxicity were 18.53, 53.01, 89.98 and >100 μg a.i.·bee-1, respectively. The HQ values were all less than 50. The 24 h-LR50 (median lethal rate) values of acute toxicity to T. ostriniae were 1.88×10-4, 5.46×10-4, 2.12×10-3 and 1.68×10-3 mg a.i.·cm-2, respectively, and the RQ values were 0.16, 0.23, 0.59 and 0.51, respectively. The results indicated that the four multi-combination nicosulfurons all exhibited low toxicity and low risk to A. mellifera, whereas to T. ostriniae 8% nicosulfuron·halosulfuron-methyl OD and 16% nicosulfuron·mesotrione·halosulfuron-methyl OD posed a high risk, and 36% nicosulfuron·atrazine OD and 22% nicosulfuron·halosulfuron-methyl·fluroxypyr-meptyl OD were moderate. Therefore, an interval is recommended between releasing T. ostriniae and applying the herbicides.
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