Pilling Edward, Campbell Peter, Coulson Mike, Ruddle Natalie, Tornier Ingo
JSC International Limited, Harrogate, North Yorkshire, United Kingdom.
PLoS One. 2013 Oct 23;8(10):e77193. doi: 10.1371/journal.pone.0077193. eCollection 2013.
Neonicotinoid residues in nectar and pollen from crop plants have been implicated as one of the potential factors causing the declines of honey bee populations. Median residues of thiamethoxam in pollen collected from honey bees after foraging on flowering seed treated maize were found to be between 1 and 7 µg/kg, median residues of the metabolite CGA322704 (clothianidin) in the pollen were between 1 and 4 µg/kg. In oilseed rape, median residues of thiamethoxam found in pollen collected from bees were between <1 and 3.5 µg/kg and in nectar from foraging bees were between 0.65 and 2.4 µg/kg. Median residues of CGA322704 in pollen and nectar in the oilseed rape trials were all below the limit of quantification (1 µg/kg). Residues in the hive were even lower in both the maize and oilseed rape trials, being at or below the level of detection of 1 µg/kg for bee bread in the hive and at or below the level of detection of 0.5 µg/kg for hive nectar, honey and royal jelly samples. The long-term risk to honey bee colonies in the field was also investigated, including the sensitive overwintering stage, from four years consecutive single treatment crop exposures to flowering maize and oilseed rape grown from thiamethoxam treated seeds at rates recommended for insect control. Throughout the study, mortality, foraging behavior, colony strength, colony weight, brood development and food storage levels were similar between treatment and control colonies. Detailed examination of brood development throughout the year demonstrated that colonies exposed to the treated crop were able to successfully overwinter and had a similar health status to the control colonies in the following spring. We conclude that these data demonstrate there is a low risk to honey bees from systemic residues in nectar and pollen following the use of thiamethoxam as a seed treatment on oilseed rape and maize.
农作物花蜜和花粉中的新烟碱类残留被认为是导致蜜蜂种群数量下降的潜在因素之一。在采食经噻虫嗪处理的开花种子玉米后采集的蜜蜂花粉中，噻虫嗪的残留中值在1至7微克/千克之间，花粉中代谢物CGA322704（噻虫胺）的残留中值在1至4微克/千克之间。在油菜中，从蜜蜂采集的花粉中噻虫嗪的残留中值在<1至3.5微克/千克之间，采食蜜蜂的花蜜中残留中值在0.65至2.4微克/千克之间。油菜试验中花粉和花蜜中CGA322704的残留中值均低于定量限（1微克/千克）。在玉米和油菜试验中，蜂箱中的残留量甚至更低，蜂箱中蜂粮的残留量处于或低于1微克/千克的检测水平，蜂箱花蜜、蜂蜜和蜂王浆样品的残留量处于或低于0.5微克/千克的检测水平。还研究了田间蜜蜂群体面临的长期风险，包括敏感的越冬阶段，连续四年对用噻虫嗪处理种子以推荐的防虫剂量种植的开花玉米和油菜进行单次处理作物暴露试验。在整个研究过程中，处理组和对照组蜂群在死亡率、觅食行为、蜂群强度、蜂群重量、幼虫发育和食物储存水平方面相似。对全年幼虫发育的详细检查表明，接触处理过的作物的蜂群能够成功越冬，并且在次年春天与对照蜂群的健康状况相似。我们得出结论，这些数据表明，在油菜和玉米上使用噻虫嗪作为种子处理后，花蜜和花粉中的内吸性残留对蜜蜂的风险较低。
