Body size is an important life-history trait in eusocial insects which plays a key role in colony fitness. The division of labour, represented by caste polyethism, correlates with divergent morphological traits. Size polymorphism has been noted in the tropical fire ant, Solenopsis geminata; however, little is known regarding the differences in the size distributions of workers performing foraging tasks. In the present study, task partitioning was observed in the foraging activities of S. geminata. Two subgroups among foraging workers of S. geminata were discovered using the Gaussian mixture model: a large worker group (head width ≥ 0.924 mm) and a small worker group (head width < 0.924 mm). The foraging worker population comprised two distinct groups – 25.64% were large workers and 74.36% were small workers. Larger workers delivered heavier seeds faster than smaller workers, but this difference became less apparent when lighter seeds were being carried. When large prey such as crickets was encountered during foraging, S. geminata partitioned their tasks into cutting and transportation. The large workers were observed to cut cricket prey into fragments with their longer mandibles, and the small workers then transported these fragments back to the nest. These results present evidence of task partitioning among tropical fire ants, with different tasks being performed by ants of different castes.

中文翻译：

---

携带者和切割者：热带火蚁（Solenopsis geminata）中依赖于大小的种姓多民族主义

体型是群居昆虫的重要生活史特征，在群体适应性中起关键作用。以种姓多民族主义为代表的劳动分工与不同的形态特征相关。在热带火蚁中已经注意到大小多态性，紫荆花; 然而，关于执行觅食任务的工人的体型分布差异知之甚少。在本研究中，任务划分在觅食活动中观察到。小号.双子座. 觅食工人中的两个亚组小号.双子座使用高斯混合模型发现：一个大工人组（头部宽度 ≥ 0.924 毫米）和一个小工人组（头部宽度 < 0.924 毫米）。觅食工人人口由两个不同的群体组成——25.64% 为大型工人，74.36% 为小型工人。较大的工人比较小的工人更快地交付较重的种子，但是当携带较轻的种子时，这种差异就变得不那么明显了。在觅食过程中遇到蟋蟀等大型猎物时，S. geminata将他们的任务划分为切割和运输。观察到大型工蚁用较长的下颚将蟋蟀猎物切成碎片，然后小型工蚁将这些碎片运回巢穴。这些结果提供了热带火蚁之间任务划分的证据，不同种姓的蚂蚁执行不同的任务。