动物个性描述的是个体行为差异会随着时间的推移而在不同环境或情形下保持稳定一致的个体行为倾向。这类现象在一些哺乳类、鸟类、爬行类、两栖类、鱼类、节肢动物中已经得到了相当详细的研究。近二十年来，动物个性俨然已经成为动物行为学领域中的一大研究热点。动物个性研究领域中最为重要也最为基础的两个问题分别是动物个性差异如何产生，以及这种差异如何在自然界中被稳定保留下来。

在探索个性特征如何出现以及如何稳定进化的过程中，许多研究关注的是个性特征与适合度之间的关系。关于个性是否影响交配策略的问题受到的关注仍然较少，不同个性特征的个体在交配行为策略选择上是否存在相应的权衡仍未得到很好地回答。本文以赤拟谷盗（Tribolium castaneum）实验室种群作为研究对象，首先通过开场实验、纸盒逃离实验、假死实验、斑块寻找实验，分别从活动性、勇敢性和探索性三个维度衡量赤拟谷盗雄性的个性特征。随后，为雄性个体随机选择雌性个体进行配对实验，记录交配行为，并进一步探讨不同个性特征的个体是否在繁殖策略上有差异。同时，我们也在实验中设置了不同的性别比例，探讨不同的竞争环境下赤拟谷盗个性特征与繁殖策略的关系变化，以验证延滞效应理论（Carry-Over Effects）。

结果显示，赤拟谷盗的活动性、假死行为、纸盒逃离行为均表现出较高的可重复性，说明赤拟谷盗在这些个性特征上具有稳定的个体差异。我们发现体型大小是影响赤拟谷盗交配行为与繁殖策略的一个主要因素，体型较大的个体有更好的繁殖表现，具体包括首次交配前间隔时长较短，交配次数较多，每次交配持续时长较长，所产后代数量较多。尽管如此，我们发现纸盒逃离用时与交配次数及后代数量表现出显著正相关关系，即害羞个体有更好的繁殖表现及更多后代。我们认为这可能与环境中的性别比例差异有关。

在实验中加入性别比例条件差异后，我们发现，赤拟谷盗繁殖表现随着竞争压力的增加受到显著的负面影响。然而，在我们的实验中并未发现符合延滞效应理论的现象，勇敢个体在竞争激烈的环境中的繁殖表现与害羞个体的无显著差异。我们认为，这可能是由于实验中所设置的性别比例不够极端，雄性竞争压力强度不够而造成的。

总的来说，体型大小是影响赤拟谷盗繁殖策略的重要因素之一，但个性特征对其繁殖策略也具有显著影响作用，未来仍需在实验室中人工操控不同的性别比例来进一步解释这背后的机制。

Animal personality is defined as stable individual differences in behaviors over time and under different environments or situations. This phenomenon has been studied remarkably in mammals, birds, reptiles, amphibians, fish and arthropods. Animal personality has become a hot spot in animal behavior researches in the past two decades. The two most important and fundamental issues in this field have been how the differences in animal personality occurs, and how the differences are kept stably in nature.

To assess the evolution of animal personality, many studies have focused on the relationship between personality traits and the corresponding fitness. However, whether the personality traits can affect the mating behaviour, and whether an individual has a trade-off among reproductive strategies has not yet been well answered. In this paper, we conducted different behavioural experiments using red flour beetles (Tribolium castaneum). We firstly conducted the open field experiment, emergence experiment, death-feigning experiment, and the patch discovery experiment to assess the personality traits of male beetles on three dimensions (activity, boldness and exploration). We then assigned random female mates to the male beetles and recorded the mating behaviours. We would like to assess whether males with different personality traits can have different reproductive strategies. We also set up different sex ratio conditions to explore whether to competition can affect the relationship between the personality traits and reproductive strategies, and then verify the carry-over effects theory.

Our results showed that the activity, emergence, and death-feigning behavior of red flour beetles were all highly repeatable, indicating stable individual differences. We found that body size played a major role in affecting the mating behaviors and reproductive strategies of red flour beetle. Larger individuals had better reproductive performances, i.e., they had shorter latency to the first copulation, a larger number of mating, longer duration of each mating and produced more offspring. However, the time of emerging from shelter showed significantly positive relationships with mating times and the number of offspring. It represents that the relatilvely shy individuals would have better reproductive performance and produce more offspring. We suggest that this may be related to the set of female biased sex ratio in the environment.

After conducting experiments under different sex ratio conditions, we found that the reproductive performances of red flour beetle would be declined significantly due to the increased male-male competition. However, our results did not conform to the Carry-over Effects theory that there is no significant difference between bold individuals and shy individuals in reproductive performance under the more competitive environments. We suggest that this may be related to the sex ratio conditions we set in the experiments, as it is not so extreme enough and the intensity of male-male competition pressure is not severe enough.

In general, body size is a key factor affecting the reproductive strategies of red flour beetles, while personality traits can also influence the reproductive strategies significantly. It is necessary to manipulate different sex ratios to investigate how the competition affects the effect of personality on reproductive behaviours.