摘要:
通过单次饲喂高浓度阿维菌素药液以及连续饲喂亚致死浓度阿维菌素药液进行意大利蜜蜂的经口染毒，从而探讨阿维菌素对意大利蜜蜂的急性及慢性毒性影响。结果表明，阿维菌素对意大利蜜蜂急性经口毒性48 h半数致死剂量(48 h-LD50)为0.00700 μg a.i.·蜂-1，慢性经口毒性240 h每日半数致死剂量(240 h-LDD50)为0.000308 μg a.i.·蜂-1·天-1。在亚致死效应方面，0.0233 mg a.i.·L-1和0.0467 mg a.i.·L-1处理组在168 h后摄食量出现明显的减少，说明阿维菌素中毒已经严重影响意大利蜜蜂的觅食和摄食能力。同时，由于摄食量的下降以及阿维菌素的毒性作用，造成了0.0467 mg a.i.·L-1处理组意大利蜜蜂体重的大幅度下降，试验前后的体重变化率达到-54.84%。意大利蜜蜂爬行能力的测定结果显示，各处理组的爬行通过率均低于对照组，特别是0.0117 mg a.i.·L-1处理组、0.0233 mg a.i.·L-1处理组和0.0467 mg a.i.·L-1处理组(P<0.05)。综上所述，阿维菌素对意大利蜜蜂的急性经口毒性为高毒，较高剂量染毒会引起意大利蜜蜂的直接死亡；此外，长期接触较低浓度的阿维菌素，一方面会损害意大利蜜蜂的运动能力，如爬行、飞行能力的减弱；另一方面意大利蜜蜂生理方面也会遭到威胁，表现为摄食量下降、体重减轻，甚至死亡。因此，在施用该农药时应尽量避开蜜蜂栖息地，同时避免在蜜源植株花期时施用。
Abstract:
The in vivo oral toxicity of abamectin on honeybees were studied here via oral feeding, with either a single-dose of high concentration abamectin to determine the acute effects, or regular feedings at sub-lethal levels for the chronic effects. The results showed that the acute dose was 0.00700 μg a.i.·bee-1 (48 h-LD50), while the chronic dose was 0.000308 μg a.i.·bee-1·d-1 (240 h-LDD50). In the sub-lethal cases, the subjects of two groups (0.0233 mg a.i.·L-1 and 0.0467 mg a.i.·L-1) developed significantly-decreased food intake after 168 h, suggesting that abamectin poisoning had severely impaired their foraging ability. Besides, the toxic effects remained prominent even in groups being mildly treated but regularly exposed to abamectin of 0.0467 mg a.i.·L-1, and the subjects had lost 54.86% of their weights after the trial. The crawling ability of honeybees was another indicator employed to evaluate the toxicity, and all treatment groups exhibited lower passing rates than that of the control, especially for groups of 0.0117, 0.0233 and 0.0467 mg a.i.·L-1 (P<0.05). In conclusion, oral abamectin was highly toxic to honeybees, and acute poisoning resulting from high-dose exposure normally led to instant death. Long-term exposure to abamectin at sub-lethal levels on the other hand, would significantly jeopardize the physical conditions by compromising the athletic abilities including foraging, crawling and flying, all of which together with weight loss eventually caused a high mortality rate. Therefore, the spraying of such pesticide is supposed to be kept away from the honeybee habitats, as well as entomophilous flowers during their florescence.
点击查看大图
下载:
