Ratz Tom, Kramer Jos, Veuille Michel, Meunier Joël
Zoological Institute, Evolutionary Biology, Johannes Gutenberg University Mainz, Mainz, Germany.
Institut Systématique Evolution Biodiversité ISYEB-UMR 7205 CNRS, MNHN, UPMC, EPHE, Paris-Sciences-Lettres, 75005, Paris, France.
Oecologia. 2016 Oct;182(2):443-52. doi: 10.1007/s00442-016-3685-3. Epub 2016 Jun 21.
The last reproductive event of a female is often associated with major changes in terms of both maternal and offspring life-history traits. However, the nature of these changes and the importance of population-specific environmental constraints in shaping their expression are difficult to predict and, as a consequence, poorly understood. Here, we investigated whether and how life-history traits vary between reproductive events and whether this variation is population-dependent in the European earwig Forficula auricularia. In this insect species, females produce up to two clutches during their lifetime and express extensive forms of maternal care. We conducted a common garden experiment, in which we measured 11 life-history traits of the first and second clutches of 132 females originating from three populations. Our results showed that clutch size was higher and the level of care expressed towards juveniles lower in second as compared to the first clutches in all three populations. In contrast, we found a population-specific effect on whether and how the reproductive event shaped juvenile quality and a trade-off between egg developmental time and female weight at hatching. Overall, these findings emphasise that the last reproductive event of a female entails both positive and negative effects on various life-history traits of the female herself and her clutch of juveniles. Moreover, our study stresses the importance of population idiosyncrasies on the expression and nature of such cohort-specific effects.
雌性的最后一次繁殖事件通常与母体和后代生活史特征方面的重大变化相关联。然而，这些变化的性质以及特定种群环境限制在塑造其表现方面的重要性很难预测，因此人们对此了解甚少。在这里，我们研究了欧洲蠼螋（Forficula auricularia）的生活史特征在繁殖事件之间是否以及如何变化，以及这种变化是否依赖于种群。在这种昆虫物种中，雌性在其一生中最多可产两窝卵，并表现出广泛的母性关怀形式。我们进行了一项共同花园实验，在实验中我们测量了来自三个种群的132只雌性的第一窝和第二窝卵的11个生活史特征。我们的结果表明，与所有三个种群的第一窝卵相比，第二窝卵的窝卵数更高，而对幼虫表现出的关怀水平更低。相比之下，我们发现了一种特定于种群的效应，即繁殖事件如何以及是否塑造幼虫质量，以及卵发育时间与孵化时雌性体重之间的权衡。总体而言，这些发现强调，雌性的最后一次繁殖事件对雌性自身及其一窝幼虫的各种生活史特征既有积极影响也有消极影响。此外，我们的研究强调了种群特性对这种特定群体效应的表现和性质的重要性。
