The moment-to-moment tasks performed by an individual can change in response to a shift of internal, e.g. body size or age, and external conditions, e.g. the number of workers currently engaged in another task. For this reason, the term “task allocation” is replacing the earlier concept of “division of labor” for describing an invariable association between worker body size and task. In the present study we hypothesized that, in the absence of changing conditions, different sized workers tend to perform different tasks. We also evaluated, using baits, the ability of colonies to regulate foraging activity through interactions between outgoing and returning foragers and the effect of ground temperature on the relative participation of different-sized workers to the foraging activity. Results suggest the existence in large and well-established colonies inhabiting a typical Mediterranean grassland area, of different-sized workers performing different tasks outside the nests. Moreover, we noticed the ability of colonies to adjust the relative participation of different sized foragers when provided with different-sized resources (baits). Finally, we recorded an effect of temperature on the average size of foragers, although no effect on size distribution was found.

中文翻译：

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地中海收获蚁 Messor wasmanni（膜翅目，蚁科）中不同觅食者群体执行的任务和觅食活动的调节

个人执行的即时任务会随着内部（例如身体大小或年龄）和外部条件（例如当前从事另一项任务的工人数量）的变化而变化。出于这个原因，术语“任务分配”正在取代早期的“分工”概念，用于描述工人体型和任务之间的不变关联。在本研究中，我们假设，在没有变化的条件下，不同规模的工人倾向于执行不同的任务。我们还使用诱饵评估了群体通过外出和返回觅食者之间的相互作用调节觅食活动的能力，以及地面温度对不同体型工人对觅食活动的相对参与的影响。结果表明，在典型的地中海草原地区存在大型且完善的殖民地，不同规模的工人在巢穴外执行不同的任务。此外，我们注意到当提供不同大小的资源（诱饵）时，菌落能够调整不同大小的觅食者的相对参与。最后，我们记录了温度对觅食者平均尺寸的影响，但没有发现对尺寸分布的影响。