Male-killing, the death of male offspring induced by maternally transmitted microbes, is classified as early, or late, male-killing. The primary advantage afforded by early male-killing, which typically occurs during embryogenesis, is the reallocation of resources to females, that would have otherwise been consumed by males. Meanwhile, the key advantage of late male-killing, which typically occurs during late larval development, is the maximized potential for horizontal transmission. To date, no studies have reported on the associated developmental and physiological effects of host coinfection with early and late male-killers, which may have a significant impact on the population dynamics of the male-killers. Here we used a lepidopteran tea pest Homona magnanima as a model, which is a unique system wherein an early male-killer (a Spiroplasma bacterium) and a late male-killer (an RNA virus) can coexist in nature. An artificially established matriline, coinfected with both Spiroplasma and RNA virus, exhibited embryonic death (early male-killing) as seen in the host line singly infected with Spiroplasma. Moreover, the coinfected line also exhibited developmental retardation and low pupal weight similar to the host line singly infected with the RNA virus. A series of field surveys revealed that Spiroplasma-RNA virus coinfection occurs in nature at a low frequency. Hence, although the two male-killers are capable of coexisting within the H. magnanima population independently, high associated fitness cost appears to limit the prevalence of male-killer coinfection in the field host population.

雄性杀伤是由母亲传播的微生物导致的雄性后代死亡，被分为早期或晚期雄性杀灭。早期雄性杀死所产生的主要优势（通常发生在胚胎发生过程中）是将资源重新分配给雌性，否则这些资源将被雄性消耗掉。同时，通常在后期幼虫发育期间发生的晚期雄性杀害的主要优势是水平传播的最大潜力。迄今为止，尚无关于早期和晚期男性杀手合并感染宿主的相关发育和生理效应的研究的报道，这可能会对男性杀手的种群动态产生重大影响。在这里，我们使用了鳞翅目茶害虫Homona magnanima作为模型，这是一个独特的系统，其中早期雄性杀手（螺旋体细菌）和晚期雄性杀手（RNA病毒）可以自然共存。人工感染的母体细胞同时感染了螺旋体和RNA病毒，在单独感染了螺旋体的宿主细胞系中表现出胚胎死亡（男性早期死亡）。而且，与单用RNA病毒感染的宿主细胞相似，共感染的细胞系也表现出发育迟缓和低p重量。一系列现场调查显示，螺旋体-RNA病毒共感染自然发生的频率较低。因此，尽管这两个男性杀手能够在巨人嗜血杆菌中共存 在独立的人群中，高昂的相关健身成本似乎限制了田间寄主人群中男性杀手合并感染的流行。