Mycetomoellerius guianensis

Quick Summary

• Difficulty: Medium
• Origin & Habitat: Guyana in the Guiana Shield region of South America, a tropical rainforest environment with high humidity and consistent warm temperatures year-round ^[1][2].
• Colony Type: Colony structure is unconfirmed. Most Attini establish single-queen colonies, but specific data for this species is lacking.
• Size & Growth:
  • Queen: Size data unavailable, no measurements exist in scientific literature.
  • Worker: Size data unavailable, the original worker description exists but specific measurements are not readily available.
  • Colony: Colony size is unconfirmed for this specific species. Related Trachymyrmex species typically reach several hundred to a few thousand workers.
  • Growth: Growth rate is unconfirmed, likely moderate based on typical fungus-growing ant patterns.
  • Development: Unconfirmed. Based on typical Attini patterns, expect 6-10 weeks at tropical temperatures (24-28°C). (Development time is estimated from related fungus-growing ant species, direct observations for this species are unavailable.)
• Antkeeping:
  • Temperature: Keep at 24-28°C. This species comes from tropical Guyana, so warmth is essential for colony health and fungal cultivation. A heating cable on one side of the nest can create a gentle gradient.
  • Humidity: High humidity is critical, aim for 70-85%. These ants come from the humid Guiana Shield rainforest. The nest substrate should remain consistently moist but not waterlogged. Mist occasionally and provide a water source.
  • Diapause: No, as a tropical species from near the equator, they do not require hibernation. Keep temperatures stable year-round.
  • Nesting: In captivity, they do well in test tubes initially, then transition to Y-tong (AAC), plaster, or soil nests with chambers scaled to their small size. The nest must retain moisture well. Provide fungal substrate material (see Feeding section).
• Behavior: Behavior is not specifically documented for this species. Attini species are generally focused on fungal cultivation rather than defense. Workers are small, so escape prevention should be moderate, they can fit through small gaps but are not extreme escape artists. They maintain close contact with their fungal garden and may be less active outside the nest compared to predatory ants.
• Common Issues: Limited documentation makes specific care requirements uncertain, keepers should be prepared to experiment and observe colony responses., Fungal colony health is critical, if the fungus dies, the ant colony will starve. This is the most common failure point for fungus-growing ant keepers., High humidity requirements can lead to mold problems if ventilation is inadequate. Balance humidity with some airflow., Tropical species are sensitive to temperature drops, cold drafts can weaken or kill colonies., Wild-caught colonies may arrive with damaged fungal gardens or parasites that are difficult to treat in captivity.

Fungal Cultivation - The Heart of Their Care

Mycetomoellerius guianensis belongs to the Attini tribe, the fungus-growing ants. Unlike most ants that hunt prey or collect honeydew, these ants cultivate specialized fungi for food. This is the most critical aspect of their care. In the wild, workers forage for plant material (dead leaves, flower petals, fruit scraps) to feed their fungal garden. The ants eat the specialized structures the fungus produces, called gongylidia. Without a healthy fungal colony, your ants will starve regardless of what other food you offer. To succeed with this species, you must prioritize fungal health over everything else. Provide small pieces of fresh plant material (lettuce, rose petals, apple, or other soft vegetation) regularly. Remove uneaten plant material before it molds. The fungus should appear as a white, fuzzy growth in the nest chamber. If the fungus turns black or slimy, remove the affected portion immediately and reduce moisture. ^[1][3]

Feeding and Nutrition

The primary food for Mycetomoellerius guianensis is their cultivated fungus, not conventional ant foods. Offer small pieces of fresh plant material every few days: soft lettuce leaves, rose petals, apple bits, or similar fruit and vegetable matter. Avoid citrus and strongly acidic foods. Remove uneaten plant material within 24-48 hours to prevent mold contamination of the nest. While the fungus is their primary food, you can occasionally offer tiny amounts of sugar water (very dilute) or honey diluted with water, but do not rely on these, the fungus is their natural diet. Some keepers report that their fungus-growing ants will accept very small insects occasionally, but plant material is more important. The key is maintaining a healthy fungal garden rather than offering varied foods. ^[1]

Temperature and Humidity

As a tropical species from Guyana, Mycetomoellerius guianensis requires warm and humid conditions. Keep the nest area at 24-28°C consistently. Temperature drops below 20°C can weaken the colony and damage the fungal garden. Use a low-level heating cable under or on one side of the nest if your room temperature is below this range. Humidity should remain high at 70-85%. The nest substrate should feel consistently moist but never waterlogged. You can achieve this by connecting a water tube to the nest and allowing the cotton to slowly water the substrate. Check moisture levels every few days and refill the water tube before it empties. Dry conditions will kill the fungal garden rapidly. ^[1][2]

Housing and Nest Setup

Start newly caught or purchased colonies in a simple test tube setup with a water reservoir. Once the colony reaches 20-30 workers and you can see a healthy fungal mass developing, you can transition them to a small Y-tong (AAC) nest or formicarium. The chambers should be appropriately sized for their small workers, not too large or open. The nest material should retain moisture well without molding easily. Plaster nests work well for fungus-growing ants because they hold humidity. Always provide an outworld (foraging area) where you can place fresh plant material. Ensure the connection between nest and outworld is secure, while not extreme escape artists, small workers can slip through gaps. ^[3]

Colony Development and Growth

Fungus-growing ants typically have slower colony growth compared to predatory species because they must build their fungal food source alongside their worker population. Expect the first few workers to appear over several months, and the colony may remain small (under 50 workers) for the first year. Once established, growth can accelerate, with colonies potentially reaching several hundred workers over several years. The queen lays eggs, and the larvae are fed by the fungal gongylidia produced by the workers' fungal garden. The timing from egg to worker depends on temperature but likely takes 6-10 weeks at optimal warmth. Be patient with this species, the reward is watching a thriving fungal garden develop alongside your ant colony. ^[1]

Frequently Asked Questions

Report an Issue

The current care sheet is based fully on literature. See inconsistencies, or something that's incorrect? Please report here, it will be resolved after review from an admin. Contributing to the blogs tab also helps providing information, to make us be able to further improve the caresheets. Thank you for your support!

References