Differing evolutionary interests of males and females may result in sexual conflict, whereby traits or behaviours that are beneficial for male reproductive success (e.g., traits related to male-male competition) are costly for females. Since sexual conflict may play an important role in areas such as speciation, population persistence or evolution of life history traits, understanding what factors modulate the intensity of sexual conflict is important. This study aims to examine juvenile diet quality as one of the underestimated ecological factors that may affect the intensity of sexual conflict via individual conditions. I used food manipulation during the development of the mite Sancassania berlesei to investigate the effects on male reproductive behaviour and competitiveness, male-induced harm to female fitness and female resistance to this harm. Males that were exposed to low-quality food started mating later than the control males, and number of their mating attempts were lower compared to those of control males. Moreover, males from the low-quality diet treatment sired fewer offspring under competition than males from the control treatment. However, the fitness of females exposed to males reared on a poor diet did not differ from that of females mated with control males. Furthermore, female diet quality did not alter their resistance to male-induced harm. Overall, diet quality manipulation affected male reproductive behaviour and mating success. However, I found no evidence that the intensity of sexual conflict in S. berlesei depends on male or female conditions. Investigating a broader range of environmental factors will provide a better understanding of sexual conflict dynamics and its feedback into associated evolutionary mechanisms.

中文翻译：

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Sancassania berlesei 幼年的饮食质量和性冲突的强度。


雄性和雌性不同的进化利益可能会导致性冲突，从而有利于雄性繁殖成功的特征或行为（例如，与雄性之间的竞争相关的特征）对于雌性来说代价高昂。由于性冲突可能在物种形成、种群持久性或生活史特征的进化等领域发挥重要作用，因此了解哪些因素调节性冲突的强度非常重要。本研究旨在探讨青少年饮食质量作为被低估的生态因素之一，可能通过个体条件影响性冲突的强度。我在 Sancassania berlesei 螨虫的发育过程中使用食物处理来研究其对雄性繁殖行为和竞争力的影响、雄性对雌性健康造成的伤害以及雌性对这种伤害的抵抗力。接触低质量食物的雄性比对照雄性开始交配的时间晚，并且与对照雄性相比，它们的交配尝试次数也较少。此外，接受低质量饮食治疗的雄性在竞争中比接受对照治疗的雄性生育的后代更少。然而，暴露于不良饮食喂养的雄性的雌性的健康状况与与对照雄性交配的雌性没有差异。此外，女性饮食质量并没有改变她们对男性造成的伤害的抵抗力。总体而言，饮食质量控制会影响雄性的生殖行为和交配成功率。然而，我没有发现任何证据表明伯氏链球菌性冲突的强度取决于雄性或雌性的情况。研究更广泛的环境因素将有助于更好地理解性冲突动态及其对相关进化机制的反馈。