The flexibility of organisms to respond plastically to their environment is fundamental to their fitness and evolutionary success. Social insects provide some of the most impressive examples of plasticity, with individuals exhibiting behavioral and sometimes morphological adaptations for their specific roles in the colony, such as large soldiers for nest defense. However, with the exception of the honey bee model organism, there has been little investigation of the nature and effects of environmental stimuli thought to instigate alternative phenotypes in social insects. Here, we investigate the effect of repeated threat disturbance over a prolonged (17 month) period on both behavioral and morphological phenotypes, using phenotypically plastic leaf-cutting ants (Atta colombica) as a model system. We found a rapid impact of threat disturbance on the behavioral phenotype of individuals within threat-disturbed colonies becoming more aggressive, threat responsive, and phototactic within as little as 2 weeks. We found no effect of threat disturbance on morphological phenotypes, potentially, because constraints such as resource limitation outweighed the benefit for colonies of producing larger individuals. The results suggest that plasticity in behavioral phenotypes can enable insect societies to respond to threats even when constraints prevent alteration of morphological phenotypes.

中文翻译：

---

干扰威胁对切叶蚁群的影响：一项实验室研究

生物体对其环境做出可塑性反应的灵活性是它们的适应性和进化成功的基础。群居昆虫提供了一些最令人印象深刻的可塑性例子，个体表现出行为适应，有时甚至表现出形态适应，以适应其在群体中的特定角色，例如用于巢穴防御的大型士兵。然而，除了蜜蜂模式生物之外，很少有关于环境刺激的性质和影响的调查，环境刺激被认为会引发社会昆虫的替代表型。在这里，我们使用表型塑料切叶蚂蚁（Atta colombica）作为模型系统，研究了长时间（17 个月）反复威胁干扰对行为和形态表型的影响。我们发现威胁干扰对受到威胁干扰的群体内个体行为表型的快速影响在短短 2 周内变得更具攻击性、威胁响应性和趋光性。我们发现威胁干扰对形态表型没有影响，这可能是因为资源限制等限制超过了生产更大个体的群体的好处。结果表明，行为表型的可塑性可以使昆虫社会对威胁做出反应，即使限制阻止了形态表型的改变。因为诸如资源限制之类的限制超过了生产更大个体的殖民地的好处。结果表明，行为表型的可塑性可以使昆虫社会对威胁做出反应，即使限制阻止了形态表型的改变。因为诸如资源限制之类的限制超过了生产更大个体的殖民地的好处。结果表明，行为表型的可塑性可以使昆虫社会对威胁做出反应，即使限制阻止了形态表型的改变。