Department of Entomology, Cornell University, Ithaca, NY.
Pesticide Management Education Program, Cornell University, Ithaca, NY.
Environ Entomol. 2021 Feb 17;50(1):107-116. doi: 10.1093/ee/nvaa138.
Both ecosystem function and agricultural productivity depend on services provided by bees; these services are at risk from bee declines which have been linked to land use change, pesticide exposure, and pathogens. Although these stressors often co-occur in agroecosystems, a majority of pollinator health studies have focused on these factors in isolation, therefore limiting our ability to make informed policy and management decisions. Here, we investigate the combined impact of altered landscape composition and fungicide exposure on the prevalence of chalkbrood disease, caused by fungi in the genus Ascosphaera Olive and Spiltoir 1955 (Ascosphaeraceae: Onygenales), in the introduced solitary bee, Osmia cornifrons (Radoszkowski 1887) (Megachilidae: Hymenoptera). We used both field studies and laboratory assays to evaluate the potential for interactions between altered landscape composition, fungicide exposure, and Ascosphaera on O. cornifrons mortality. Chalkbrood incidence in larval O. cornifrons decreased with high open natural habitat cover, whereas Ascosphaera prevalence in adults decreased with high urban habitat cover. Conversely, high fungicide concentration and high forest cover increased chalkbrood incidence in larval O. cornifrons and decreased Ascosphaera incidence in adults. Our laboratory assay revealed an additive effect of fungicides and fungal pathogen exposure on the mortality of a common solitary bee. Additionally, we utilized phylogenetic methods and identified four species of Ascosphaera with O. cornifrons, both confirming previous reports and shedding light on new associates. Our findings highlight the impact of fungicides on bee health and underscore the importance of studying interactions among factors associated with bee decline.
生态系统功能和农业生产力都依赖于蜜蜂提供的服务；这些服务正面临蜜蜂数量减少的威胁，而蜜蜂数量减少与土地利用变化、农药暴露和病原体有关。尽管这些胁迫因素在农业生态系统中经常同时发生，但大多数传粉媒介健康研究都集中在这些因素的单独作用上，因此限制了我们做出明智的政策和管理决策的能力。在这里，我们研究了改变的景观组成和杀菌剂暴露对 chalkbrood 病流行的综合影响， chalkbrood 病是由属 Ascosphaera Olive 和 Spiltoir 1955（Ascosphaeraceae：Onygenales）中的真菌引起的，引入的独居蜜蜂 Osmia cornifrons（Radoszkowski 1887）（Megachilidae：Hymenoptera）。我们使用现场研究和实验室试验来评估改变的景观组成、杀菌剂暴露和 Ascosphaera 对 O. cornifrons 死亡率的相互作用的潜力。幼虫 O. cornifrons 的 chalkbrood 发病率随着开阔自然栖息地覆盖率的增加而降低，而成年 O. cornifrons 的 Ascosphaera 患病率随着城市栖息地覆盖率的增加而降低。相反，高杀菌剂浓度和高森林覆盖率增加了幼虫 O. cornifrons 的 chalkbrood 发病率，降低了成年 O. cornifrons 的 Ascosphaera 发病率。我们的实验室试验表明，杀菌剂和真菌病原体暴露对一种常见的独居蜜蜂的死亡率有相加作用。此外，我们利用系统发育方法鉴定了与 O. cornifrons 相关的四种 Ascosphaera 物种，这既证实了以前的报告，又揭示了新的关联。我们的研究结果强调了杀菌剂对蜜蜂健康的影响，并强调了研究与蜜蜂减少相关的因素相互作用的重要性。
