Martinez Abraham, Calhoun Austin C, Sadd Ben M
School of Biological Sciences, Illinois State University, Normal, IL, United States.
Front Insect Sci. 2023 Aug 17;3:1207058. doi: 10.3389/finsc.2023.1207058. eCollection 2023.
Diet can have an array of both direct and indirect effects on an organism's health and fitness, which can influence the outcomes of host-pathogen interactions. Land use changes, which could impact diet quantity and quality, have imposed foraging stress on important natural and agricultural pollinators. Diet related stress could exacerbate existing negative impacts of pathogen infection. Accounting for most of its nutritional intake in terms of protein and many micronutrients, pollen can influence bee health through changes in immunity, infection, and various aspects of individual and colony fitness. We investigate how adult pollen consumption, pollen type, and pollen diversity influence bumble bee survival and infection outcomes for a microsporidian pathogen . Experimental pathogen exposures of larvae occurred in microcolonies and newly emerged adult workers were given one of three predominantly monofloral, polyfloral, or no pollen diets. Workers were assessed for size, pollen consumption, infection 8-days following adult-eclosion, survival, and the presence of extracellular microsporidian spores at death. Pollen diet treatment, specifically absence of pollen, and infection independently reduced survival, but we saw no effects of pollen, pollen type, or pollen diet diversity on infection outcomes. The latter suggests infection outcomes were likely already set, prior to differential diets. Although infection outcomes were not altered by pollen diet in our study, it highlights both pathogen infection and pollen availability as important for bumble bee health, and these factors may interact at different stages of bumble bee development, at the colony level, or under different dietary regimes.
饮食对生物体的健康和适应性会产生一系列直接和间接的影响，而这可能会影响宿主与病原体相互作用的结果。土地利用变化可能会影响饮食的数量和质量，给重要的自然和农业传粉者带来觅食压力。与饮食相关的压力可能会加剧病原体感染已有的负面影响。花粉在蛋白质和许多微量营养素方面占其大部分营养摄入，它可以通过免疫力、感染以及个体和蜂群适应性的各个方面的变化来影响蜜蜂的健康。我们研究成年蜜蜂对花粉的消耗、花粉类型和花粉多样性如何影响熊蜂对一种微孢子虫病原体的存活和感染结果。幼虫的实验性病原体暴露在小蜂群中进行，新出现的成年工蜂被给予三种主要为单一花源、多花源或无花粉饮食中的一种。在成年工蜂羽化8天后，对工蜂的大小、花粉消耗、感染情况、存活情况以及死亡时细胞外微孢子虫孢子的存在情况进行评估。花粉饮食处理，特别是无花粉，以及感染独立地降低了存活率，但我们没有看到花粉、花粉类型或花粉饮食多样性对感染结果有影响。后者表明，在不同饮食之前，感染结果可能已经确定。虽然在我们的研究中感染结果没有因花粉饮食而改变，但它突出了病原体感染和花粉供应对熊蜂健康都很重要，并且这些因素可能在熊蜂发育的不同阶段、蜂群层面或不同饮食模式下相互作用。
