Mycetomoellerius relictus

Quick Summary

• Difficulty: Medium
• Origin & Habitat: Northern South America including Brazil, Colombia, French Guiana, Guyana, Peru, Suriname, Trinidad and Tobago, and Venezuela. Found in both primary forest and open cultivated fields ^[1][3].
• Colony Type: Colony type is unconfirmed. Like other Attini, likely single-queen colonies based on typical genus patterns.
• Size & Growth:
  • Queen: 5.5-6.1mm ^[2]
  • Worker: 3.5-4.7mm ^[2]
  • Colony: Likely up to several hundred workers at maturity based on related species in the genus
  • Growth: Moderate, fungus-farming ants typically grow more slowly than generalist ants due to the time needed to cultivate fungal gardens
  • Development: Estimated 8-12 weeks at optimal temperature based on typical Attini development patterns (Development depends heavily on fungal garden health. First workers (nanitics) will be smaller and take longer than subsequent broods.)
• Antkeeping:
  • Temperature: Keep at 24-28°C. These are tropical ants that need warm, stable conditions ^[4]. A heating cable on one side of the nest creates a gentle gradient.
  • Humidity: High humidity is essential, aim for 70-80% relative humidity. Fungus farmers need consistently moist substrate to support their fungal gardens. Keep the nest substrate damp but not waterlogged.
  • Diapause: No true diapause expected. As tropical ants from northern South America, they likely remain active year-round with no hibernation requirement.
  • Nesting: Soil-based nesting is essential. Use a naturalistic setup with moist soil or a plaster nest with a soil chamber. They need depth (at least 15-20cm) for their fungal garden chambers. Test tubes with cotton and a soil chamber work well for founding colonies.
• Behavior: Very timid and non-aggressive. Workers will play dead when disturbed rather than biting or stinging ^[3]. They are slow-moving and not escape artists, making them easy to contain. As fungus farmers, they spend considerable time tending to their fungal gardens rather than foraging aggressively. They collect plant material to cultivate their fungi.
• Common Issues: Fungal garden collapse is the biggest risk, if the fungus dies, the colony starves. Keep humidity stable and avoid contamination., Overheating can kill both the ants and their fungal gardens, avoid temperatures above 30°C., Dry conditions cause fungal gardens to dry out and die, monitor humidity closely., Slow growth frustrates some keepers, fungus farmers grow more slowly than typical ants, sometimes taking months for first workers., Wild colonies may have parasites that can devastate captive colonies, quarantine and observe new colonies carefully.

Fungal Farming - The Core of Their Diet

Mycetomoellerius relictus belongs to the tribe Attini, a group of ants that have evolved a unique agricultural symbiosis with fungi. Unlike most ants that hunt insects or collect honeydew, these ants cultivate fungal gardens for their primary food source. The queen carries a fungal pellet (a fragment of the fungal cultivar) when she founds her colony, using it to start a new garden that becomes the colony's food source ^[4]. In the wild, their fungal gardens have been found containing small seeds, showing they incorporate plant material into their fungal substrate ^[5]. In captivity, you must provide appropriate fungal substrate, typically a moist mixture of plant material (leaves, flower petals, or specialized fungal substrate) that the ants can cultivate. The fungal garden requires high humidity and stable temperatures to thrive. If the fungus dies, the colony will starve, making fungal garden health the single most important factor for success.

Nest Setup and Housing

These ants need soil-based nesting setups that allow for fungal garden chambers. In the wild, colonies have been found at depths of at least 20cm underground, so provide deep soil chambers when possible ^[3]. A naturalistic setup with moist soil in a container works well, or you can use a plaster nest with a dedicated soil chamber. The nest should have a water reservoir to maintain humidity without flooding. For the outworld (foraging area), provide space for the ants to bring in plant material for their fungal garden. Test tubes work for the initial founding chamber, but plan to move the colony to a larger setup once the first workers emerge. They do not need elaborate escape prevention since they are slow-moving and not aggressive, but a standard barrier is still recommended.

Feeding and Nutrition

Unlike typical ants that accept a wide variety of foods, Mycetomoellerius relictus requires fungal cultivation as their primary food source. Provide small pieces of fresh plant material (leaves, flower petals, grass clippings) that the ants will use to cultivate their fungal garden. The plant material should be pesticide-free and changed regularly to prevent mold. Some keepers also offer small amounts of sugar water or honey occasionally, but the fungal garden should be the primary food source. Do not feed them insects as a primary protein source, they are not predatory like some other ant species. The fungal garden is sensitive to contamination, so keep all food offerings clean and remove uneaten plant material before it molds.

Temperature and Humidity Control

Maintain temperatures between 24-28°C for optimal colony health and fungal garden growth ^[4]. Temperatures below 20°C can slow or stop fungal growth, while temperatures above 30°C can kill both the ants and the fungus. Use a heating cable on one side of the nest to create a temperature gradient if your room temperature is below 24°C. Place the heating cable on top of the nest, not underneath, to avoid evaporating moisture too quickly. Humidity is equally critical, keep the nest substrate consistently moist at 70-80% relative humidity. The fungal garden requires damp conditions to survive. Use a water reservoir or mist regularly to maintain moisture, but avoid standing water that could drown the colony. A hygrometer helps monitor conditions accurately.

Behavior and Handling

Mycetomoellerius relictus is one of the most docile ant species you can keep. When disturbed, workers simply feign death rather than attempting to bite, sting, or flee ^[3]. This makes them excellent for observation and handling, though their slow movement means they are not particularly exciting to watch compared to more active species. They are not aggressive and pose no danger to keepers. Their small size (3.5-4.7mm for workers) means they can squeeze through small gaps, so use appropriate barriers. They are not prolific foragers and spend much of their time tending the fungal garden. Colonies are relatively quiet and do not produce strong alarm pheromones when disturbed.

Colony Founding and Early Development

Newly mated queens carry a fragment of the parental fungal garden when they establish a new colony, this is essential for starting their agricultural system ^[4]. The queen seals herself in a claustral chamber and raises her first workers using stored fat reserves while cultivating the fungal fragment. First workers (nanitics) will be smaller than normal workers and may take several months to emerge, depending on temperature and fungal garden success. Do not disturb the founding chamber during this time, the queen needs stability to succeed. Once the first workers emerge, they will begin tending the fungal garden and foraging for additional plant material. Growth is slower than typical ants because the colony must build both its worker population and its fungal garden simultaneously.

Frequently Asked Questions

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References