The influence of long-term storage on the evolution of social insect male ejaculates remains a puzzle. Here, we studied the influence of sperm storage on male ejaculates in the stingless bee Scaptotrigona aff. depilis, a species where queens mate with a single male and thus do not trigger sperm competition. We estimated quantitative genetic parameters by sampling males from six colonies and two consecutive generations (n = 172). Heritability for sperm length was lower than heritability estimates for other traits. Coefficients of additive genetic variance (CVa) suggest sperm viability and sperm counts are under directional selection, sperm length under stabilizing selection, and male size under weak selection. Both genetic and phenotypic correlations were weak and not significant, indicating independent trait evolution. Overall, our findings provide evidence of selection acting on social insect ejaculates and bring insights for stingless bee breeding programs.

中文翻译：

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一夫一妻制的无刺蜜蜂（Scaptotrigona aff. depilis）的长期储存形状射精特征

长期储存对社会昆虫雄性射精进化的影响仍然是一个谜。在这里，我们研究了精子储存对无刺蜂 Scaptotrigona aff 雄性射精的影响。depilis，一种蚁后与单个雄性交配的物种，因此不会引发精子竞争。我们通过从六个菌落和连续两代（n = 172）中对雄性进行采样来估计定量遗传参数。精子长度的遗传力低于其他性状的遗传力估计值。加性遗传变异系数 (CVa) 表明精子活力和精子数量处于定向选择之下，精子长度处于稳定选择之下，而雄性大小则处于弱选择之下。遗传和表型相关性都很弱且不显着，表明独立的性状进化。全面的，