Dipartimento di Scienze AgroAlimentari, Ambientali e Animali (DI4A), Università degli Studi di Udine, Udine, Italy.
PLoS One. 2023 Jul 17;18(7):e0288821. doi: 10.1371/journal.pone.0288821. eCollection 2023.
Host age at parasites' exposure is often neglected in studies on host-parasite interactions despite the important implications for epidemiology. Here we compared the impact of the parasitic mite Varroa destructor, and the associated pathogenic virus DWV on different life stages of their host, the western honey bee Apis mellifera. The pre-imaginal stages of the honey bee proved to be more susceptible to mite parasitization and viral infection than adults. The higher viral load in mite-infested bees and DWV genotype do not appear to be the drivers of the observed difference which, instead, seems to be related to the immune-competence of the host. These results support the existence of a trade-off between immunity and growth, making the pupa, which is involved in the highly energy-demanding process of metamorphosis, more susceptible to parasites and pathogens. This may have important implications for the evolution of the parasite's virulence and in turn for honey bee health. Our results highlight the important role of host's age and life stage at exposure in epidemiological modelling. Furthermore, our study could unravel new aspects of the complex honey bee-Varroa relationship to be addressed for a sustainable management of this parasite.
尽管宿主-寄生虫相互作用的研究往往忽略了宿主暴露于寄生虫时的年龄，但这对流行病学具有重要意义。在这里，我们比较了寄生螨瓦螨和相关的致病性病毒 DWV 对其宿主西方蜜蜂 Apis mellifera 不同生命阶段的影响。蜜蜂的未成熟阶段比成虫更容易受到螨虫寄生和病毒感染。螨寄生的蜜蜂中的高病毒载量和 DWV 基因型似乎不是导致观察到的差异的驱动因素，相反，这似乎与宿主的免疫能力有关。这些结果支持免疫和生长之间存在权衡，使参与高度耗能的变态过程的蛹更容易受到寄生虫和病原体的影响。这可能对寄生虫毒力的进化以及对蜜蜂健康的影响具有重要意义。我们的研究结果强调了宿主暴露时的年龄和生命阶段在流行病学模型中的重要作用。此外，我们的研究可以揭示蜜蜂-瓦螨关系的复杂新方面，以实现对这种寄生虫的可持续管理。
