Abstract Animals often disperse from one habitat to another to access mates or suitable breeding sites. The costs and benefits of such movements depend, in part, on the dispersing individuals’ phenotypes, including their sex and age. Here we investigated dispersal and road-related mortality in larvae of a bioluminescent beetle, the European common glow-worm, Lampyris noctiluca , in relation to habitat, sex and proximity of pupation. We expected these variables to be relevant to larval dispersal because adult females are wingless, whereas adult males fly when searching for glowing females. We found that dispersing glow-worm larvae were almost exclusively females and close to pupation. The larvae were often found on a road, where they were able to move at relatively high speeds, with a tendency to uphill orientation. However, each passing vehicle caused a high mortality risk, and we found large numbers of larvae run over by cars, especially close to covered, forest-like habitat patches. In contrast, adult females in the same area were most often found glowing in more open rocky and grassy habitats. These findings demonstrate an underappreciated ecological strategy, sex-biased dispersal at larval phase, motivated by different habitat needs of larvae and wingless adult females. The results are also consistent with roads being an ecological trap, facilitating dispersal and presumably females’ signal visibility but causing severe larval mortality just before the reproductive stage. Hence, in addition to the previously recognised threats of urbanisation, even low traffic volumes have a high potential to negatively affect especially females of this iconic beetle. Significance statement Animals sometimes need to move from one habitat to another to find mating partners or breeding sites. We found this need to result in strongly female-biased larval dispersal in the European common glow-worm, a beetle known for the glow of wingless females that attract flying males to mate. Female larvae moving between habitats often used a road or trail but perished in high numbers when run over by cars. Hence, roads are likely to be ecological traps for the female glow-worm larvae, attracting them during dispersal, but causing grave mortality. The sex-biased larval dispersal, demonstrated in this study, is a poorly known ecological strategy that was found to be very risky in a human-modified landscape.

中文翻译：

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标志性甲虫雌性偏向幼虫传播过程中的高道路死亡率

摘要 动物经常从一个栖息地分散到另一个栖息地以获得配偶或合适的繁殖地点。这种迁移的成本和收益部分取决于分散个体的表型，包括他们的性别和年龄。在这里，我们调查了生物发光甲虫（欧洲常见的萤火虫 Lampyris noctiluca）幼虫的散布和道路相关死亡率与栖息地、性别和化蛹距离的关系。我们预计这些变量与幼虫传播有关，因为成年雌性没有翅膀，而成年雄性在寻找发光的雌性时会飞翔。我们发现散布的萤火虫幼虫几乎都是雌性的，并且接近化蛹。幼虫经常在道路上被发现，它们能够以相对较高的速度移动，并倾向于上坡。然而，每一辆经过的车辆都会造成很高的死亡风险，我们发现大量幼虫被汽车碾过，尤其是在靠近被覆盖的森林状栖息地的地方。相比之下，同一地区的成年女性最常被发现在更开阔的岩石和草地栖息地发光。这些发现证明了一种未被充分认识的生态策略，幼虫阶段的性别偏向扩散，其动机是幼虫和无翅成年雌性的不同栖息地需求。结果也与道路是一个生态陷阱一致，它促进了传播和可能的雌性信号可见性，但在繁殖阶段之前导致严重的幼虫死亡。因此，除了先前公认的城市化威胁之外，即使是低交通量也很有可能对这种标志性甲虫尤其是雌性产生负面影响。意义说明 动物有时需要从一个栖息地迁移到另一个栖息地以寻找交配伙伴或繁殖地。我们发现这需要导致欧洲常见萤火虫中强烈偏向雌性的幼虫传播，这种甲虫以无翅雌性的光芒吸引飞行的雄性交配而闻名。在栖息地之间移动的雌性幼虫通常使用道路或小径，但在被汽车碾压时大量死亡。因此，道路很可能成为雌性萤火虫幼虫的生态陷阱，在它们散布期间吸引它们，但导致它们严重死亡。在这项研究中证明的性别偏见的幼虫散布是一种鲜为人知的生态策略，被发现在人类改造的景观中非常危险。我们发现这需要导致欧洲常见萤火虫中强烈偏向雌性的幼虫传播，这种甲虫以无翅雌性的光芒吸引飞行的雄性交配而闻名。在栖息地之间移动的雌性幼虫通常使用道路或小径，但在被汽车碾压时大量死亡。因此，道路很可能成为雌性萤火虫幼虫的生态陷阱，在它们散布期间吸引它们，但导致它们严重死亡。在这项研究中证明的性别偏见的幼虫散布是一种鲜为人知的生态策略，被发现在人类改造的景观中非常危险。我们发现这需要导致欧洲常见萤火虫中强烈偏向雌性的幼虫传播，这种甲虫以无翅雌性的光芒吸引飞行的雄性交配而闻名。在栖息地之间移动的雌性幼虫通常使用道路或小径，但在被汽车碾压时大量死亡。因此，道路很可能成为雌性萤火虫幼虫的生态陷阱，在它们散布期间吸引它们，但导致它们严重死亡。在这项研究中证明的性别偏见的幼虫散布是一种鲜为人知的生态策略，被发现在人类改造的景观中非常危险。在栖息地之间移动的雌性幼虫通常使用道路或小径，但在被汽车碾压时大量死亡。因此，道路很可能成为雌性萤火虫幼虫的生态陷阱，在它们散布期间吸引它们，但导致它们严重死亡。在这项研究中证明的性别偏见的幼虫散布是一种鲜为人知的生态策略，被发现在人类改造的景观中非常危险。在栖息地之间移动的雌性幼虫通常使用道路或小径，但在被汽车碾压时大量死亡。因此，道路很可能成为雌性萤火虫幼虫的生态陷阱，在它们散布期间吸引它们，但导致它们严重死亡。在这项研究中证明的性别偏见的幼虫散布是一种鲜为人知的生态策略，被发现在人类改造的景观中非常危险。