page_title: Messor barbarus
section_title: Division of labor in trail foraging behavior
hierarchical_section_title: Messor barbarus / Behavior / Division of labor in trail foraging behavior
caption_attribution_description: Español: Hormiga granera (Messor barbarus)
context_page_description: Messor Barbarus is a species of harvester ant in the subfamily Myrmicinae. It is found In Southern Europe and Northern Africa.
context_section_description: Small seeds, such as oat fragments or canary seeds, are favored for triggering the onset of recruitment and mobilization of harvesting in Messor barbarus populations. This is because they allow for a faster rate of return between the initial discovery of the food source and the subsequent return of scouts to the nest to relay information to the greater population. The trail is adjusted by a fleet of initial scouts which enhance the harvesting patterns to select for the preferred seed size. Worker ants are divided into three distinct size classes which in turn correspond to the size of the seeds harvested. All of the ants participate in the process of trail-laying, but within the size classes there are distinct roles. The majority of ants in the harvesting arena are Media ants, which are responsible primarily for trail-laying. Minor ants are most efficient in carrying smaller seeds such as oat fragments. Major ants are primarily involved in the harvesting of larger or more preferred seed species. The collective action of M. barbarus favors the minimization of foraging time rather than maximized efficiency of the energetic gain per item harvested. On the whole, group cooperation allows for a successful balance to be struck between the benefits of maximized food exploitation and colony-wide energy gain and the costs associated with increased predation risk.
  These different classes of workers cooperate to transport loads of seeds, often forming a transport chain. The first workers tend to be smaller to medium-sized, which corresponds to a high loading ratio. Lower loading ratios correspond to those larger workers which tend to align towards the end of the transport chain, transporting the larger goods for the colony. Overall, this strategy reduces time spent in transport to the nest and results in a net benefit to the colony.
caption: Messor barbarus workers
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