Diapause in seasonal environments allows insects to survive adverse seasons. However, individuals can sometimes enter a prolonged diapause for more than a year, and also skip favourable seasons, which can bring additional costs through e.g. loss of metabolic resources. At the same time, prolonged diapause can be beneficial if it allows individuals to have a risk-spreading strategy to skip potentially suboptimal breeding seasons. We studied if prolonged diapause (2-year diapause) negatively affects the fertility and fitness of female and male Colorado potato beetles (Leptinotarsa decemlineata) compared to control (1-year diapause) beetles. We also tested the parental effects on the subsequent chemical stress tolerance of their offspring. We found that prolonged diapause carried fertility costs only for females who were less fertile than the control females. However, no differences in fertility were observed in males. Furthermore, prolonged diapause in females resulted in offspring with lower larvae-to-adult survival even though these offspring had accelerated development times. In contrast, paternal diapause duration had no effects on their offspring larvae-to adult survival, but prolonged diapause males sired offspring with slower development times than control males. Perhaps to compensate the costs related to prolonged diapause both older parents produced or sired offspring with higher body mass than control parents. Despite the differences in emergence mass, parental diapause duration did not affect offspring insecticide stress tolerance. The difference between females and males most likely results from the observed differences in prolonged diapause females’ capacity to fight against cellular oxidative damage which was poorer compared to the control females. Even though prolonged diapause allows individuals to have a risk-spreading strategy it carries sex-specific fertility and fitness costs indicating that selection could favour this in males but not in females.

中文翻译：

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长期滞育具有特定性别的生育能力和健身成本

季节性环境中的滞育使昆虫能够在不利的季节生存。然而，个体有时会进入长达一年以上的滞育期，并且还会跳过有利的季节，这会通过例如代谢资源的损失而带来额外的成本。同时，如果长期滞育允许个体采取风险分散策略来跳过潜在的次优繁殖季节，则它可能是有益的。我们研究了与对照（1 年滞育）甲虫相比，长期滞育（2 年滞育）是否对雌性和雄性科罗拉多马铃薯甲虫（Leptinotarsa decemlineata）的生育力和健康产生负面影响。我们还测试了父母对其后代随后的化学应激耐受性的影响。我们发现，长期滞育仅对生育能力低于对照女性的女性造成生育成本。然而，在男性中没有观察到生育力的差异。此外，雌性长期滞育导致后代的幼虫到成虫存活率较低，即使这些后代的发育时间加快。相比之下，父系滞育持续时间对其后代幼虫到成虫的存活率没有影响，但滞育时间延长的雄性后代的发育时间比对照雄性慢。也许是为了补偿与长期滞育相关的成本，年长的父母生产或生育的后代体重比对照父母高。尽管出现质量存在差异，但父母滞育持续时间并不影响后代杀虫剂胁迫耐受性。雌性和雄性之间的差异很可能是由于观察到的长期滞育雌性对抗细胞氧化损伤的能力存在差异，与对照雌性相比较差。尽管长期滞育允许个体采取风险分散策略，但它会带来特定性别的生育和健康成本，表明选择可能有利于男性而不是女性。