Parasites are commonly cited as one of the causes of population declines for both managed and wild bees. Epidemiological models sometimes assume that increasing the proportion of infected individuals in a group should increase transmission. However, social insects exhibit behaviors and traits which can dampen the link between parasite pressure and disease spread. Understanding patterns of parasite transmission within colonies of social bees has important implications for how to control diseases within those colonies, and potentially the broader pollinator community. We used bumble bees (Bombus impatiens Cresson) (Hymenoptera: Apidae) and western honey bees (Apis mellifera L.) (Hymenoptera: Apidae) infected with the gut parasites Crithidia bombi (Lipa & Triggiani) (Trypanosomatida: Trypanosomatidae) and Nosema ceranae (Fries et al.) (Dissociodihaplophasida: Nosematidae), respectively, to understand how the initial proportion of infected individuals impacts within-colony spread and intensity of infection of the parasites. In bumble bees, we found that higher initial parasite prevalence increased both the final prevalence and intensity of infection of C. bombi. In honey bees, higher initial prevalence increased the intensity of infection in individual bees, but not the final prevalence of N. ceranae. Measures that reduce the probability of workers bringing parasites back to the nest may have implications for how to control transmission and/or severity of infection and disease outbreaks, which could also have important consequences for controlling disease spread back into the broader bee community.

中文翻译：

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蜜蜂和熊蜂群体中小孢子虫和锥虫寄生虫的群体内传播


寄生虫通常被认为是管理蜜蜂和野生蜜蜂数量下降的原因之一。流行病学模型有时假设增加群体中受感染个体的比例会增加传播。然而，群居昆虫表现出的行为和特征可能会削弱寄生虫压力与疾病传播之间的联系。了解社会性蜜蜂群体内寄生虫传播的模式对于如何控制这些群体内的疾病以及潜在的更广泛的传粉昆虫群体具有重要意义。我们使用感染肠道寄生虫 Crithidiaombi（Lipa 和 Triggiani）（锥虫目：锥虫科）和微孢子虫（Nosema ceranae）的大黄蜂（Bombus impatiens Cresson）（膜翅目：蜜蜂科）和西方蜜蜂（Apis mellifera L.）（膜翅目：蜜蜂科）。 Fries 等人）（Dissociodihaplophasida：Nosematidae）分别了解感染个体的初始比例如何影响寄生虫的群体内传播和感染强度。在大黄蜂中，我们发现较高的初始寄生虫流行率会增加熊蜂的最终流行率和感染强度。在蜜蜂中，较高的初始流行率会增加个体蜜蜂的感染强度，但不会增加中华蜂的最终流行率。降低工蜂将寄生虫带回巢穴的可能性的措施可能会对如何控制感染和疾病爆发的传播和/或严重程度产生影响，这也可能对控制疾病传播回更广泛的蜜蜂群落产生重要影响。