Apterostigma carinatum

Quick Summary

• Difficulty: Hard
• Origin & Habitat: Tropical lowland rainforests of Colombia, Ecuador, and Brazil (Pará), found in primary and secondary forest, logged areas, and pasture from 85-400m elevation ^[1][2][3][4].
• Colony Type: Unconfirmed, colony structure data is unavailable for this species.
• Size & Growth:
  • Queen: Size data unavailable, inferred from Apterostigma genus to be approximately 5-7mm.
  • Worker: Size data unavailable, inferred from Apterostigma genus to be approximately 3-4mm.
  • Colony: Unknown, Apterostigma colonies typically remain small.
  • Growth: Slow
  • Development: Estimated 8-12 weeks based on related fungus-growing ants. (Fungus-growing ants typically develop slower than predatory species.)
• Antkeeping:
  • Temperature: Keep warm and stable, roughly 24-28°C based on tropical lowland distribution. Avoid temperatures below 20°C.
  • Humidity: High humidity required, keep nest substrate consistently damp but not waterlogged.
  • Diapause: No, tropical species that remains active year-round.
  • Nesting: Naturalistic setup with soil or rotting wood. They nest in soil and leaf litter in nature ^[2].
• Behavior: Cryptic and slow-moving with deliberate foraging behavior. Small size means escape prevention must be excellent, use fine mesh barriers and Fluon-coated surfaces. As Attini, they possess a functional stinger but it is less medically significant to humans.
• Common Issues: fungus garden contamination or failure is the primary cause of colony death in captive fungus-growing ants., difficulty obtaining founding queens, they are rarely collected and founding behavior is unconfirmed., sensitivity to desiccation, colonies die quickly if humidity drops., slow growth rate requires patience, colonies may take years to develop.

Natural History and Distribution

Apterostigma carinatum inhabits the tropical lowlands of northwestern South America. In Colombia, they are found in the departments of Valle del Cauca, Nariño, Chocó, and Vaupés ^[1][3][4]. The species also occurs in Ecuador and has been recorded in Pará, Brazil ^[1][2].

Collection records show they live at elevations from 85 meters (Taraira, Vaupés) up to 400 meters (Rio Tatabro, Valle del Cauca) ^[1][5]. They show flexibility in habitat use, found in undisturbed primary forest but also in logged forest, burnt forest, secondary growth, and even pasture ^[2]. This suggests they can tolerate some habitat disturbance, though they remain dependent on forest floor conditions with suitable nest sites and fungus-growing substrates.

Nest Preferences and Setup

In nature, these ants nest in soil and leaf litter on the forest floor ^[2]. They require humid, stable microhabitats that support their fungus gardens.

For captive care, use a naturalistic setup with a soil-based nest or plaster nest that can hold moisture. Include a foraging area with leaf litter and small pieces of rotting wood to mimic their natural environment. The nest must maintain high humidity, the substrate should feel damp to the touch but not waterlogged. Provide a temperature gradient by placing a heating cable on one side of the nest, keeping the warm side around 26-28°C and allowing a slight drop to 24°C on the cool side.

Fungus Cultivation and Feeding

As members of the Attini tribe (fungus-growing ants), Apterostigma carinatum cultivate symbiotic fungus on organic substrates ^[1]. Unlike leaf-cutter ants, they do not cut leaves but instead collect insect frass (insect droppings), dead plant material, and other debris to feed their fungus gardens.

In captivity, provide small amounts of dried leaves, flower petals, or insect frass. They also need protein sources, offer tiny pieces of insects, fish flakes, or boiled egg which the workers will process to feed the fungus. Never allow the fungus garden to dry out or become contaminated with mold. If the fungus turns gray, white, or develops black spots, the garden is failing and the colony is in danger.

Temperature and Environmental Care

Being from tropical lowland forests, they require warm stable temperatures. Aim for 24-28°C with minimal fluctuation ^[1][2]. Sudden temperature drops below 20°C can stress the fungus garden and kill the colony.

High humidity is critical, maintain damp nest material and limited ventilation. However, avoid stagnant air which promotes mold. Use small ventilation holes with fine mesh to balance humidity and air exchange. Check the fungus garden daily, it should look healthy and slightly moist, never dry or moldy.

Behavior and Temperament

These ants are cryptic and slow-moving, spending much of their time tending the fungus garden rather than foraging aggressively. They possess a functional stinger typical of Attini ants, though it is less medically significant to humans.

Because of their small size, escape prevention must be excellent. Use Fluon (a slippery barrier) on the upper walls of the foraging area and fine mesh (less than 1mm) on any ventilation. Even tiny gaps in lids or tubing will allow workers to escape.

Frequently Asked Questions

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References