Fluctuating asymmetry (FA) is defined as small, random deviations from perfect bilateral symmetry in a morphological trait. It has sometimes been used as an indicator of male quality because it affects male mating success. In the Japanese scorpionfly, Panorpa japonica , males are known to use two mating tactics, donation of nuptial gifts and forced mating. In P. japonica , low FA males are more likely to win a competition with another male, and females prefer low FA male sex pheromones. However, no studies have been conducted on the effect of FA on the mating tactics adopted by males. In the present study, we first observed the mating behaviors of P. japonica and classified these into three patterns: (1) nuptial gifting, (2) forced mating, and (3) feeding mating. Second, we investigated the relationships between mating tactics and male traits, including body size, FA, and weapon size. The results showed a positive correlation between absolute FA and mating duration only in the case of feeding mating. We discuss the reasons why this significant correlation was found in P. japonica.

中文翻译：

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日本蝎子的交配策略与雄性特征（如体型和波动的不对称性）之间的关系

波动不对称 (FA) 被定义为形态特征中与完美双侧对称性的小的随机偏差。它有时被用作雄性质量的指标，因为它会影响雄性交配成功。在日本蝎蛉（Panorpa japonica）中，众所周知，雄性会使用两种交配策略，赠礼和强制交配。在 P. japonica 中，低 FA 雄性更有可能赢得与另一只雄性的竞争，而雌性更喜欢低 FA 雄性信息素。然而，尚未对 FA 对雄性采用的交配策略的影响进行研究。在本研究中，我们首先观察了粳稻的交配行为，并将其分为三种模式：（1）送礼，（2）强迫交配，（3）喂食交配。其次，我们调查了交配策略和男性特征之间的关系，包括体型、FA 和武器尺寸。结果表明，仅在喂食交配的情况下，绝对 FA 与交配持续时间呈正相关。我们讨论了在 P. japonica 中发现这种显着相关性的原因。