Institute of Apicultural Research, Chinese Academy of Agricultural Sciences, Beijing 100093, PR China; Key Laboratory of Pollinating Insect Biology, Ministry of Agriculture, Beijing 100093, PR China.
Guangdong Key Laboratory of Animal Conservation and Resource Utilization, Guangdong Public Laboratory of Wild Animal Conservation and Utilization, Guangdong Institute of Applied Biological Resources, Guangzhou 510260, PR China.
Sci Total Environ. 2018 Jul 15;630:487-494. doi: 10.1016/j.scitotenv.2018.02.258. Epub 2018 Mar 7.
Though honeybee populations have not yet been reported to be largely lost in China, many stressors that affect the health of honeybees have been confirmed. Honeybees inevitably come into contact with environmental stressors that are not intended to target honeybees, such as pesticides. Although large-scale losses of honeybee colonies are thought to be associated with viruses, these viruses usually lead to covert infections and to not cause acute damage if the bees do not encounter outside stressors. To reveal the potential relationship between acute pesticides and viruses, we applied different doses of imidacloprid to adult bees that were primarily infected with low levels (4.3×10 genome copies) of chronic bee paralysis virus (CBPV) to observe whether the acute oral toxicity of imidacloprid was able to elevate the level of CBPV. Here, we found that the titer of CBPV was significantly elevated in adult bees after 96h of acute treatment with imidacloprid at the highest dose 66.9ng/bee compared with other treatments and controls. Our study provides clear evidence that exposure to acute high doses of imidacloprid in honeybees persistently infected by CBPV can exert a remarkably negative effect on honeybee survival. These results imply that acute environmental stressors might be one of the major accelerators causing rapid viral replication, which may progress to cause mass proliferation and dissemination and lead to colony decline. The present study will be useful for better understanding the harm caused by this pesticide, especially regarding how honeybee tolerance to the viral infection might be altered by acute pesticide exposure.
尽管目前尚未报道中国的蜜蜂种群大量减少，但许多影响蜜蜂健康的应激源已得到证实。蜜蜂不可避免地会接触到并非专门针对蜜蜂的环境应激源，例如杀虫剂。尽管大规模的蜜蜂群损失被认为与病毒有关，但这些病毒通常会导致隐性感染，如果蜜蜂不遇到外部应激源，就不会造成急性损伤。为了揭示急性杀虫剂和病毒之间的潜在关系，我们应用不同剂量的吡虫啉处理主要感染慢性蜜蜂麻痹病毒（CBPV）的成年蜜蜂，以观察急性口服吡虫啉的毒性是否能够提高 CBPV 的水平。在这里，我们发现与其他处理和对照相比，在最高剂量 66.9ng/bee 的急性处理后 96 小时，感染慢性蜜蜂麻痹病毒的成年蜜蜂中 CBPV 的滴度明显升高。我们的研究提供了明确的证据，表明急性高剂量吡虫啉暴露于持续感染 CBPV 的蜜蜂中，会对蜜蜂的生存产生显著的负面影响。这些结果表明，急性环境应激源可能是导致病毒快速复制的主要加速因素之一，这可能会导致大规模增殖和传播，从而导致蜂群减少。本研究将有助于更好地了解这种杀虫剂造成的危害，特别是关于急性农药暴露如何改变蜜蜂对病毒感染的耐受性。
