Understanding how many mates an animal has in its lifetime is a critical factor in sexual selection. At the same time, differences in an organism's ecology, such as the quantity and quality of food, could be reflected in different mating rates. Mating rate had a significant effect on female net fitness (i.e., lifetime offspring production), however, laboratory measurements cannot well mirror the situation in wild. The common bedbug (Cimex lectularius) is a well-established model for studying traumatic insemination and sexual conflict. The species comprises two host lineages that feed on bats (BL) or humans (HL). HL can constantly feed on human hosts throughout the year, while BLs feed only during summer months when their bat hosts occupy the roosts. Because mating in female bedbugs is closely linked to foraging, this system provides a valuable model to study mating variation in the field. We established a new method for estimating age-dependent mating rates of females in the wild by relating the fluorescent pigment accumulation in the eyes of females to the number of mating scars that manifest as melanized spots caused by the injection of sperm through the wall of the female abdomen by the male into the spermalege. In addition, using laboratory bedbugs we found that three and a half observed matings on average lead to one observed melanized mating scar. Although young BL and HL females (with low pteridine concentrations) did not differ in the number of matings, the mating rate increased with age only in HL but not in BL females. We sampled on average older BL than HL females. The lack of access to food (bat blood) during winter could explain the lack of increase in the number of scars with age in BL. In species where mating leaves visible marks, using fluorescent pigments to determine female age (applicable to most arthropods) could be an important tool to study sexual selection and mating rate in the wild. The method can help formulate sustainable and biologically lucid approaches for their control.

中文翻译：

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不同生态的臭虫谱系与年龄相关的交配率

了解动物一生中有多少配偶是性选择的关键因素。同时，生物体生态的差异，例如食物的数量和质量，可以反映在不同的交配率上。交配率对雌性净适应性（即一生的后代产量）有显着影响，然而，实验室测量不能很好地反映野生情况。常见臭虫（Cimex lectularius）是研究创伤性授精和性冲突的成熟模型。该物种包括两个以蝙蝠（BL）或人类（HL）为食的宿主谱系。HL 可以全年不断地以人类宿主为食，而 BL 则仅在夏季，蝙蝠宿主占据栖息地时才进食。由于雌性臭虫的交配与觅食密切相关，该系统为研究野外交配变异提供了一个有价值的模型。我们建立了一种新方法，通过将雌性眼睛中的荧光色素积累与交配疤痕的数量联系起来，来估计野生雌性与年龄相关的交配率，交配疤痕表现为通过精子壁注射而引起的黑化斑点。雌性由雄性腹部进入精子。此外，使用实验室臭虫，我们发现平均观察到三次半交配会导致观察到一次黑色化交配疤痕。尽管年轻的 BL 和 HL 雌性（蝶啶浓度较低）在交配次数上没有差异，但交配率仅在 HL 中随年龄增加而增加，而在 BL 雌性中则不然。我们对 BL 女性的平均年龄比 HL 进行了抽样调查。冬季缺乏食物（蝙蝠血）可以解释 BL 的疤痕数量没有随着年龄的增长而增加。在交配留下可见标记的物种中，使用荧光颜料确定雌性年龄（适用于大多数节肢动物）可能是研究野外性选择和交配率的重要工具。该方法可以帮助制定可持续且生物学上清晰的控制方法。