Apterostigma depressum

Apterostigma depressum

Apterostigma depressum is a fungus-growing ant recorded in Peru ^[1]. Like other members of their genus, they cultivate fungus gardens as their primary food source. Based on typical Apterostigma patterns, workers are probably small, around 3-4mm, with the slender build common to Attini ants.

These ants are true fungus farmers. They do not eat the insects they collect, instead, they chew insects and plant material into a paste to grow a specific fungus garden, which then feeds the colony. This makes them fascinating but challenging pets, as you are essentially keeping two organisms, the ants and their fungus.

Quick Summary

• Difficulty: Expert
• Origin & Habitat: Peru ^[1]. Based on typical Apterostigma patterns, they likely inhabit tropical forests.
• Colony Type: Likely single-queen colonies, though specific colony structure is unconfirmed.
  • Colony: Monogyne
  • Founding: Claustral
• Size & Growth:
  • Queen: Unknown, based on typical Apterostigma patterns, likely 5-7mm.
  • Worker: Unknown, based on typical Apterostigma patterns, likely 3-4mm.
  • Colony: Likely small, under 100 workers based on typical Apterostigma patterns.
  • Growth: Slow
  • Development: Unknown, based on related fungus-growing ants, likely 8-12 weeks at 25-28°C. (Fungus-growing ants develop slowly. First workers may emerge faster than subsequent brood, but still require significant time.)
• Antkeeping:
  • Temperature: Keep warm and stable, roughly 24-28°C. Based on their Peruvian origin, they likely prefer tropical conditions.
  • Humidity: Keep the nest substrate consistently moist. The fungus garden requires high humidity to survive, think damp forest floor conditions.
  • Diapause: No, tropical species that remains active year-round.
  • Nesting: Requires a setup that accommodates a fungus garden. A container with soil or rotting wood substrate works better than standard acrylic nests.
• Behavior: Peaceful and slow-moving. They pose minimal sting risk due to small size. However, their tiny size means escape prevention must be excellent.
• Common Issues: fungus garden collapse from incorrect humidity or contamination kills the colony., chemical sensitivity means standard cleaning products or hand lotions can poison the fungus., slow growth requires patience, colonies may take months to show significant size increases., escape risk is high due to small worker size.

Fungus Garden Care

These ants are fungus-growers (Attini), which changes everything about how you keep them. They do not eat the food you provide directly. Instead, they use it to grow a fungus garden, and they eat the fungus.

You must provide fresh insect prey, such as cricket or mealworm pieces, and possibly dried leaves or flower petals. The ants chew this material into a paste that feeds the fungus. The garden needs constant humidity but not waterlogging. If the fungus turns brown or dies, the colony will starve.

Keep the garden in darkness, bright light stresses the fungus. Avoid touching the garden with bare hands, as oils and chemicals from your skin can kill it. If you need to move the colony, use clean tweezers and minimize disturbance.

Temperature and Humidity

Keep your colony warm and stable, roughly 24-28°C. Because they come from Peru, they likely prefer tropical conditions and will suffer in cooler temperatures.

Humidity is critical for the fungus garden. Keep the nest substrate consistently moist, think damp forest floor, not wet swamp. The fungus needs moisture to grow, but stagnant water causes mold.

Ventilation requires balance. Too much airflow dries out the fungus, too little causes mold. Provide small air holes or occasional opening of the container, but monitor the substrate moisture daily.

Feeding and Diet

Unlike many pet ants, Apterostigma depressum cannot survive on sugar water alone. They need a constant supply of fresh insect prey to feed their fungus garden.

Offer small pieces of cricket, mealworm, or fruit fly regularly. Remove old food before it molds, as mold can spread to the fungus garden and kill it. Some keepers also provide dried raspberry leaves, rose petals, or other plant material, which the ants use as additional substrate for the fungus.

Do not rely on honey or sugar water as primary food. While they might drink it occasionally, the colony will die without protein to sustain the fungus.

Housing and Nest Setup

Standard acrylic formicariums do not work well for fungus-growing ants. They lack the humidity and darkness the fungus needs.

Start with a test tube or small container containing soil, plaster, or rotting wood substrate. The queen needs material to start her first fungus garden. Eventually, move the colony to a larger container, a plastic box with a soil base works well.

Ensure the container has excellent escape prevention. These ants are tiny and can squeeze through minute gaps. Use tight-fitting lids with fine mesh ventilation.

Colony Founding

Specific founding behavior for this species is unconfirmed. Based on typical Apterostigma patterns, queens likely found colonies claustrally, meaning they seal themselves in a chamber and live off stored fat reserves.

However, unlike non-fungus-growing ants, the queen must bring fungus spores from her birth colony to start the garden. Without these spores, she cannot raise workers. In captivity, this means you typically need to start with an established colony or provide the queen with a small piece of fungus from another colony.

The founding chamber must be dark, humid, and undisturbed. Check on the queen only weekly, as frequent disturbance can cause her to abandon the fungus or eat her eggs.

Frequently Asked Questions

References