Scientific illustration of Apterostigma wasmannii ant - showing key identification features including head, thorax, and gaster.

Apterostigma wasmannii

Non-Parasitic Queen No Gamergate
Sci. Name
Apterostigma wasmannii
Tribe
Attini
Subfamily
Myrmicinae
Author
Forel, 1892
Distribution
Found in 1 countries
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Introduction

Apterostigma wasmannii is a small fungus-growing ant found in the forests of South America, including Brazil, French Guiana, Guyana, Suriname, and Trinidad and Tobago [AntWiki]. Researchers have collected them from leaf litter and rotting wood in semideciduous forests using Winkler extractors and pitfall traps . They have also been recorded in urban areas of southern Brazil, showing some tolerance to disturbed habitats . As members of the Attini tribe, these ants cultivate fungal gardens on collected organic matter, which serves as their primary food source [AntWiki]. This fungus-growing lifestyle makes them challenging captives that require precise humidity and temperature control. Unlike many beginner species, they cannot survive on sugar water and insects alone.

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Status by country, from Kass et al. 2022 & Wong et al. 2023

Native Invasive Introduced (indoor) Intercepted Unknown
Data Sources
Year Range 2000 - 2026

Quick Summary

  • Difficulty: Expert
  • Origin & Habitat: Brazil, French Guiana, Guyana, Suriname, and Trinidad and Tobago, forest floor leaf litter and rotting wood in semideciduous forests [1][2]
  • Colony Type: Colony structure unconfirmed for this species
  • Size & Growth:
    • Queen: Size data unavailable, inferred from Apterostigma genus to be approximately 5-7 mm
    • Worker: Size data unavailable, inferred from Apterostigma genus to be approximately 3-4 mm
    • Colony: Unknown for this species
    • Growth: Slow
    • Development: Unknown for this species (Development time is likely temperature-dependent, similar to other fungus-growing ants)
  • Antkeeping:
    • Temperature: 24-28°C, maintain stable warmth within this range [1]
    • Humidity: High, keep nest substrate consistently damp but not waterlogged. 70-80% relative humidity ideal [1]
    • Diapause: No, tropical species active year-round [1]
    • Nesting: Small cavities in hollow twigs, rotting wood, or leaf litter with excellent humidity retention [2]
  • Behavior: Slow, deliberate foragers focused on collecting substrate for fungus gardens. Generally peaceful and cryptic. Small size means excellent escape prevention is essential [1]
  • Common Issues: fungus garden contamination by mold kills colonies quickly., difficulty maintaining stable high humidity without waterlogging the nest., slow growth means months between worker generations, requiring patience., wild-caught colonies may carry parasitic mites that overwhelm captive nests., inappropriate substrate leads to fungus garden failure and colony 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, 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. Queens likely carry fungus spores in their infrabuccal pocket, similar to other Attini species, but this has not been documented for A. wasmannii specifically. The founding stage is high-risk in captivity without proper fungus starter material and stable humidity conditions.

Frequently Asked Questions

Can I keep Apterostigma wasmannii in a test tube?

Yes, but you must provide fungus substrate and maintain high humidity. Standard test tube setups work for founding if you add appropriate organic material like insect frass for fungus growth, not just a water reservoir.

How long until Apterostigma wasmannii gets first workers?

Unknown for this species specifically. Related fungus-growing ants typically take several months at warm temperatures, but this varies based on fungus health and temperature stability.

Do Apterostigma wasmannii need hibernation?

No. They come from tropical regions and remain active year-round. Keep them warm consistently throughout the year [1].

What do Apterostigma wasmannii eat?

They eat fungus that they cultivate on collected organic matter. You must provide appropriate substrate like insect frass or decaying plant material. They cannot survive on sugar water and insects alone [1].

Are Apterostigma wasmannii good for beginners?

No. They are expert-level ants due to their specialized fungus-growing requirements, need for high humidity without mold, and sensitivity to environmental conditions.

How big do Apterostigma wasmannii colonies get?

Unknown for this species. Based on related Apterostigma species, colonies likely remain small to moderate. Do not expect massive colonies like leafcutter ants.

Why are my Apterostigma wasmannii dying?

The most common cause is fungus garden failure due to mold contamination or incorrect humidity. Ensure the substrate is damp but not wet, provide ventilation to prevent mold, and avoid disturbing the nest frequently.

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References

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This caresheet is licensed under CC BY-SA 4.0 .