Abstract

Mature colonies of many social insect species exhibit division of labor (DOL) where individual workers specialize in doing only a subset of the multiple tasks needed to maintain homeostasis. In newly initiated ant colonies, however, the first workers (called nanitics) are few in number and much smaller in size than those in mature colonies. This limited workforce must perform most of the tasks of mature colonies, but it is unknown if they also exhibit DOL. In this study, we tracked several inside-nest and outside-nest behaviors of nanitics in incipient Pogonomyrmex rugosus colonies. DOL arises in these colonies, whereby the relatively oldest workers (even if only by a few hours) are biased towards foraging, while younger nanitics concentrate on brood care. The addition of new nanitics shifts behavior in the oldest individual away from brood care but does not immediately increases its foraging. Conversely, nanitics left alone due to mortality of nest-mates forage more, but do not reduce brood care. The results suggest P. rugosus nanitics follow an age-related task specialization pattern that is broadly similar to mature colonies. The nanitic life stage may be, however, unique for ants in how fine-grained the DOL is in terms of absolute age differences and flexibility for task switching.

Significance statement

The ecological success of ants is thought to be facilitated by workers dividing their labor across tasks. Commonplace in mature colonies is that individuals will perform safer, within-nest tasks such as brood care when young, and shift as they age towards riskier, outside-nest tasks such as foraging. Because many do the same task, the death of any single worker has minimal effect. We show, for the first time, a similar age-related, task specialization pattern also occurs in newly founded colonies. In this earliest life, history stage workers are small and few in number, precluding the massive task redundancy that characterizes mature colonies. Nevertheless, a division of labor correlating with relative age differences arises even when workers differ in age by only a few hours. This supports the hypothesis that a similar developmental pathway for task allocation in worker behavior occurs at all stages in colony life history.

中文翻译：

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与年龄有关的分工发生在蚁群形成的最早阶段

摘要

许多社会昆虫物种的成熟菌落表现出分工（DOL），其中个体工人专门从事维持稳态所需的多项任务中的一部分。然而，在新成立的蚂蚁殖民地中，第一批工人（被称为nanitics）的数量很少，规模也比成熟殖民地的小得多。这种有限的劳动力必须执行成熟殖民地的大多数任务，但尚不清楚他们是否也表现出DOL。在这项研究中，我们跟踪了初期Pogonomyrmex rugosus的尼尼丁胺的几种内巢和外巢行为。群落。DOL出现在这些殖民地中，相对较年长的工人（即使只有几个小时）偏向于觅食，而年轻的纳尼主义者则专注于育雏。添加新的哺乳类动物可以使最年长的个体的行为远离育雏护理，但不会立即增加其觅食。相反，由于巢伙伴的死亡率较高，无生命的人单独觅食，但不会减少育雏的照顾。结果表明P. rugosus nanitics遵循大体相似成熟的殖民地与年龄相关的任务分工格局。然而，就绝对年龄差异和任务切换的灵活性而言，DOL的细粒度对于蚂蚁而言，生命的生命周期可能是独一无二的。

重要性声明

人们认为，通过工人分工来促进蚂蚁在生态上的成功。在成熟的殖民地，常见的做法是，个体在年幼时会执行更安全的巢内任务，例如育雏，并随着年龄的增长而转向更危险的巢外任务（例如觅食）。由于许多人都执行相同的任务，因此任何单个工人的死亡影响最小。我们首次表明，在新成立的殖民地中也出现了类似的与年龄相关的任务分工模式。在这一最早的时代，历史舞台的工人人数很少，人数很少，这排除了表征成熟殖民地的大规模任务冗余。然而，即使工人的年龄差异只有几个小时，仍会出现与相对年龄差异相关的分工。