Collective stomach of ant colonies

How do ant colonies deal with the nutrients in their food? Audrey Dussutour of Center Center de recherche sur la animale cognence (CNRS / Université Paul Sabatier) and Steve Simpson from the University of Sydney have shown that each ant colony acts like a collective mouth and stomach. The members are able to solve the nutritional needs of their populations by dividing tasks (food search, digestion, and excretion).

In an ant nest, food is brought to the nest by 10% of the members - it is the members that specialize in foraging. The food will then be released and shared among all members of the pack. However, nutritional needs between young members (larvae) and mature members vary.
Recently Audrey Dussutour and Steve Simpson have shown that larvae, individuals who cannot move inside or out of ant nests, are able to communicate with worker ants about their food needs, from which worker ants there will be a suitable feeding strategy. The researchers provided protein-rich foods and sugar-rich foods for ant colonies with larvae and ant colonies without larvae, and they observed differences. For flocks with larvae members, protein-rich foods have been collected on the nests to ensure larval development. In contrast, when there are no larvae, ants favor sugar-rich foods.

Rhytidoponera sp. feeding on sugar water (Photo: Copyright Gabriel Miller)

In the second experiment, the researchers showed that sugar is the main nutrient that governs ants' food collection. When offered a variety of foods with different protein and sugar ratios, worker ants are able to harvest the same amount of sugar from each type of food. Researchers have also observed that when food is high in protein, low in sugar, excess protein is removed from the nest. That's because ants have the ability to extract sugar from food and discard nitrogen in the form of small garbage pellets.

However, despite such food processing mechanisms, ant colonies reared with protein-rich feed have a higher mortality rate due to protein poisoning and can lose up to 75% of members.Meanwhile, herds fed with lower protein content have a mortality rate of less than 5% .

Scientists found lower mortality rates in herds with larvae. They explained that ants in these herds have somewhat escaped the toxicity of protein by handing over the treatment of nutrients to the larvae, because these are individuals with better protein digestibility. other individuals. The researchers also confirmed that protein-rich foods have a highly toxic effect on ants - what they have proven in fruit flies.

References:
Dussutour et al.Communal Nutrition in Ants.Current Biology, May 12, 2009;DOI: 10.1016 / j.cub.2009.03.015