Costa Rica Leaf Cutter Ants
A great social organization hidden in the underground leaf cutter ant hill
Among the thousands of species of insects of tropical rainforest, and the more than 66,000 species in Costa Rica, the most intriguing and fascinating are the leaf cutters, which have a true social organization commanded by the ant queen. Leaf cutter ants farm a special kind of fungus underground using mulch chewed from leaves bits stripped from specific plants & trees. This have evolved as an advanced agricultural system based on the ant-fungus mutualism: They don't feed on leaves, but on certain parts of that specialized fungus that grows only in the underground chambers of the ant burrow.
The Queen Ant and its Leaf Cutter Ants Colony
Summary of Leaf Cutter Ant Facts
Scientific Name: Atta cephalotes
Habitat: The tropical rainforest and tropical dry forest, below 2,000 m (6561.7 feet) of altitude.
Length: Total: 2-20 mm (0.08-0.8 inches).
Feeds on: Fungus growing on the chewed leave pieces.
Features:
- There are four castes in established colonies: minims, minors, workers and soldiers.
- All the ants in the colony are daughters of the queen ant.
- The leaf cutter ant queen can have a size of 5 cm (2 inches), and live more than 20 years.
- Cultivation of fungus for food by fungus-farming capable ants was originated about 50 million years ago.
- Despite the damage that leaf cutter ants can made to some valuable plants, the anthill material can be used as a very quality organic fertilizer.
Despite plant devastation, these ants are recycling nutrients in the rainforest ecosystem. A leave bite ready to be carried to the ant hill.
Leaf Cutter Ants carry cargo throughout rainforest to their burrow.
Leaf cutter ants settle down large trails in the rain forest ground.
Sometimes there is the need of cooperation between two worker ants.
Even more, for some jobs, the work of a team of ants is required.
Once cut, leaf bits are carefully transported throughout rainforest to the ant burrow.
Not only the leaves are useful for these ants.
The Leaf Cutter Ant is endowed with powerful mandibles.
Leaf cutters can use any vine in the rain forest as an elevated "highway" over the ground.
Leaf Cutter Ants feed on the specialized fungus (spongy white material) that grows only on the mulch chewed from leaves.
The queen ant is the hearth of the ant burrow ant and is the mother of all the others because of its millions of eggs.
The queen ant permanently cared and attended by custodians.
The leaf cutter ant queen can be 2 inches in size.
The leaf cutter ant queen can live more than 20 years.


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Leaf cutter ants can be seen in large trails, as if parading, through the Costa Rica tropical rainforest ground on work by carrying cargo (the cut leaves bits by the workers ants) to their nests, where it will be chewed by other worker ants, mixed with their own saliva and feces, and mulched into compost or fertilizer to farm a specialized fungus. The fungus grows developing a spongy contexture and white coloration (similar to bread) of 15-30 cm, whose hyphal swellings (called "gongylidia") have inflated tips on which ants feed (because of their richness in lipids and carbohydrates derived from the leaves). The ants actively cultivate their fungus, feeding it with freshly-cut plant material, saliva and feces; as well as protecting and maintaining it free from certain pests and molds capable of damage it.
This ant activity is much like humans farm crops as a food source, and the leaf cutter ants and fungi are dependent on each other for survival, making this fact a good example of mutualistic symbiosis (mutual benefit interdependence).
Despite the potential damage that leaf cutter ants can made to valuable plants, they can be very useful. The ant hill formed by the accumulation of material extracted from the internal cavities, and the ant wastes area brought from everywhere into the colony, can be used as a very quality organic fertilizer in human farming.
A mature leaf cutter colony can contain more than 7 million ants, mostly sterile female workers. They are divided into castes, based mostly on size, that perform different functions. Size and functional difference is determined by its specialized food while at larval stage. There are four ant castes present in established colonies: minims, minors, workers and soldiers (the soldier ants are also known as majors or dinergates). Often a minim will sit on the worker ant and protects it from parasitic pest attacks.
The queen ant is the hearth of the ant burrow and is the mother of all the others. As one of the larger ants in the world, it can be 2 inches in size, can live for more that 20 years and put on millions of eggs. This work is made once time a year (from May to June in Costa Rica) with amounts of 50,000 eggs.
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