Apterostigma wasmannii

Apterostigma wasmannii

Apterostigma wasmannii is a small fungus-growing ant from the forests of South America and Trinidad and Tobago ^[1]. You will find them in the leaf litter and rotting wood of semideciduous forests, where researchers have collected them using Winkler extractors in Brazil ^[2]. They have also been recorded in urban areas of southern Brazil, showing some tolerance to disturbed habitats ^[3].

As members of the Attini tribe, these ants cultivate gardens of fungus on collected organic matter, which serves as their primary food source ^[1]. This fungus-growing lifestyle makes them fascinating but challenging captives, requiring you to maintain both the ants and their fungal crops under precise conditions of warmth and humidity. Unlike many beginner species, they cannot survive on sugar water and insects alone.

Quick Summary

• Difficulty: Expert
• Origin & Habitat: Brazil, French Guiana, Guyana, Suriname, Trinidad and Tobago, forest floor leaf litter and rotting wood in semideciduous forests ^[1][2]
• Colony Type: Likely single-queen based on typical Attini patterns, though unconfirmed for this species
• Size & Growth:
  • Queen: Unknown, likely 5-7mm based on related Apterostigma species
  • Worker: Unknown, likely 3-4mm based on genus patterns
  • Colony: Unknown, likely small to moderate based on related species
  • Growth: Slow
  • Development: Unknown, estimated 8-12 weeks at 25-27°C based on related fungus-growing ants (Development time is inferred from related Attini species, temperature significantly affects fungus growth rate)
• Antkeeping:
  • Temperature: 24-28°C (tropical forest species). Start at 25°C and adjust based on colony activity ^[1]
  • Humidity: High, keep nest substrate damp but not waterlogged, similar to forest floor conditions. 70-80% relative humidity ideal ^[1]
  • Diapause: No, tropical species active year-round ^[1]
  • Nesting: Small cavities, hollow twigs, or chambers in rotting wood with excellent humidity retention ^[2]
• Behavior: Slow, deliberate foragers focused on collecting substrate for fungus gardens. Generally peaceful and cryptic. Small size means escape prevention must be excellent ^[1]
• Common Issues: fungus garden contamination by mold or mites kills colonies quickly., difficulty maintaining stable high humidity without waterlogging the nest., slow growth means months between worker generations, requiring patience., wild-caught colonies often carry parasitic mites that overwhelm captive nests., inappropriate substrate leads to fungus garden failure and starvation.

Fungus Cultivation Requirements

Apterostigma wasmannii belongs to the Attini tribe, meaning they are obligate fungus-growers ^[1]. They cultivate fungal gardens on collected organic material, likely insect frass and decaying plant matter based on genus patterns. You must provide sterile substrate initially and maintain it at high humidity without allowing mold to take over. The ants eat the fungus, not the substrate itself. If the garden dies, the colony starves. Watch for gray or green mold spots, which indicate contamination. Success requires balancing ventilation to prevent stagnant air while keeping humidity high enough for fungal growth.

Nest Setup and Humidity Control

In nature, these ants nest in hollow twigs and rotting wood in the leaf litter ^[2]. Replicate this with small naturalistic setups featuring rotting wood, leaf litter, and tight cavities. Use a plaster nest or water tower to maintain 70-80% humidity. Place the heating element on top of the nest rather than underneath to prevent condensation from flooding the chambers. Ensure good cross-ventilation to prevent mold, but keep the substrate consistently damp to the touch. Dry conditions kill the fungus garden within days.

Temperature and Seasonal Care

Coming from tropical forests in Brazil and the Guianas, they need steady warmth between 24-28°C ^[1]. Use a heating cable on one side of the nest to create a temperature gradient so the ants can self-regulate. They do not hibernate and remain active year-round. Avoid temperatures below 20°C, as this slows fungus growth and can lead to colony decline. Keep the temperature stable rather than allowing daily fluctuations.

Feeding and Diet

They eat the fungus they grow, not the collected material itself. You must provide appropriate substrate like insect frass (caterpillar droppings), small pieces of decaying leaves, or other organic debris for the fungus to colonize. Supplement with tiny amounts of protein such as fruit flies or small insect pieces to feed the larvae and fertilize the garden. Offer sugar water occasionally, but do not rely on it as a primary food source. The fungus is their staple diet. ^[1]

Colony Founding

Founding behavior is unconfirmed for this species. Based on typical Attini patterns, queens likely practice claustral founding, sealing themselves in with a pellet of fungus spores carried in their infrabuccal pocket. The queen would live off stored body fat until the first workers hatch and begin foraging for new garden substrate. This stage is high-risk in captivity without proper fungus starter material and stable conditions.

Frequently Asked Questions

References