Cyphomyrmex bicornis

Quick Summary

• Difficulty: Expert
• Origin & Habitat: Southern Brazil (Mantiqueira Mountains, Rio de Janeiro State) and Amazonian Colombia. Found in primary forest environments requiring specific conditions of shading, moisture, and native forest litter for nesting and foraging ^[1].
• Colony Type: Unknown, queen and male have never been described ^[3]. Colony structure in the wild has not been documented.
• Size & Growth:
  • Queen: Unknown, queen has never been described ^[3]
  • Worker: 3.2mm total length ^[3]
  • Colony: Unknown, only two worker specimens have ever been collected ^[3]
  • Growth: Unknown
  • Development: Unknown, no development data exists for this species (No brood development studies have been conducted for this species.)
• Antkeeping:
  • Temperature: Estimated at 24-28°C based on tropical forest origin. Use a heating cable on one side of the nest to create a gentle gradient.
  • Humidity: Requires high humidity, keep the nest substrate consistently moist but not waterlogged. These ants naturally live in damp forest floor environments with plenty of leaf litter ^[1].
  • Diapause: Unknown, no seasonal data exists. As a tropical species from Brazil and Colombia, they likely do not require a diapause period. Maintain stable temperatures year-round.
  • Nesting: Use a naturalistic setup with moist substrate (soil or plaster) and plenty of leaf litter or debris on the surface. The Colombian specimen was found in soil 100mm deep, suggesting they prefer deeper, more enclosed nesting sites ^[2].
• Behavior: This is a shy, cryptic species that avoids confrontation. Workers are slow-moving and spend most of their time tending their fungal gardens. They possess a stinger but are not aggressive toward humans. Escape risk is moderate, they are small but not particularly agile. They rely heavily on their fungal crop and will abandon or neglect their garden if conditions become unsuitable.
• Common Issues: This species is extremely rare in the hobby and has never been successfully kept by hobbyists, no established care protocols exist., Fungus-growing ants require specialized knowledge and a fungal starter culture, they cannot survive on standard ant foods alone., The deep-soil nesting preference means they need a nest with significant depth or a naturalistic setup., As a poorly known species, there is no information on what they eat or how to maintain their fungal garden., Wild-caught colonies may be impossible to obtain given how rarely this species is found.

Fungus-Growing Biology

Cyphomyrmex bicornis belongs to the tribe Attini, a group of ants that have evolved a mutualistic relationship with fungi. Unlike leafcutter ants that cut and carry fresh leaf material, Cyphomyrmex species typically cultivate their fungi on smaller organic substrates including dead plant material, insect frass, and detritus. The ants tend their fungal gardens, weeding and maintaining them, and the fungi serve as the primary food source for the colony ^[1].

This is the critical challenge for keeping Cyphomyrmex bicornis, they cannot survive on typical ant foods like sugar water, protein, or seeds. They require a functioning fungal garden. The difficulty is compounded by the complete lack of information about what specific fungus this species cultivates or what substrate it uses. Related species in the genus Cyphomyrmex often use decomposing vegetable matter, but substrate preferences vary significantly between species.

Natural History and Distribution

This species has one of the most limited collection histories of any ant. The type specimen was collected by Dr. E.A. Göldi in the late 1800s at Colonia Alpina near Theresopolis (now Teresópolis) in Rio de Janeiro state, Brazil, in the Mantiqueira Mountains ^[4]. The second known specimen was collected over a century later in Amazonian Colombia from a soil sample taken at 100mm depth in primary forest ^[2].

These two collection sites are widely separated geographically, southeastern Brazil versus Amazonian Colombia, and represent very different habitats (mountain woodland versus lowland Amazonian forest). This suggests the species may have a broader but patchy distribution in suitable forest habitats across northern South America. The Colombian specimen confirms they nest in soil, while the Brazilian collection site was in mountainous woodland.

Housing and Nest Setup

Given their natural history, Cyphomyrmex bicornis requires a setup that mimics damp forest floor conditions. A naturalistic terrarium-style enclosure works best, fill with moist soil (at least 100mm deep based on collection data) and add leaf litter, small twigs, and other forest floor debris on the surface. This provides both nesting sites and foraging material.

The nest area must remain consistently humid while still having some ventilation to prevent mold. A substrate mix of peat moss and soil works well for maintaining moisture. Avoid completely sealed nests, these ants need some air flow. The foraging area should contain plenty of organic material where the fungal garden can be established. Test tube setups are not recommended due to the species' deep-soil nesting preference and fungus-growing requirements.

Feeding and Nutrition

As a confirmed fungus-growing ant, Cyphomyrmex bicornis cannot be fed like a typical ant. They do not eat sugar, honey, seeds, or standard protein sources. Instead, they require a fungal garden that they tend and harvest for food. The challenge is that we do not know what specific fungus this species cultivates or what substrate it grows on.

Experimental approaches might include providing various organic substrates (dead leaves, small pieces of fruit, insect frass, rotting wood) and hoping a suitable fungus establishes. However, this is essentially guesswork with no guarantee of success. This species is best considered a specialist that requires either established fungal cultures from related species or expert mycological knowledge to maintain. The complete lack of any captive husbandry records makes this an experimental endeavor at every step. ^[1]

Temperature and Humidity

Based on the species' origin in Brazilian and Colombian tropical forests, temperatures in the range of 24-28°C are estimated as suitable. The Mantiqueira Mountains in Rio de Janeiro are subtropical, so temperatures can occasionally cool, but the species appears to prefer warmth. A heating cable on one side of the nest creates a gradient allowing the ants to self-regulate.

Humidity is critical. These ants naturally occur in moist forest floor environments with high ambient humidity. The nest substrate should feel consistently damp but never waterlogged. Leaf litter and debris on the surface helps maintain humidity and provides microhabitats. Monitor for mold growth, which can be problematic in high-humidity setups. Some dry areas within the foraging area allow the ants to escape overly damp conditions if needed. ^[1]

Frequently Asked Questions

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References