Acanthostichus femoralis

Quick Summary

• Difficulty: Expert
• Origin & Habitat: Argentina and Brazil, soil-dwelling species found under cattle manure and near termite nests ^[1]
• Colony Type: Unknown, colony structure unconfirmed
• Size & Growth:
  • Queen: Size data unavailable, inferred from genus to be approximately 5-7mm
  • Worker: Approximately 3-4mm total length ^[1]
  • Colony: Unknown, likely small based on cryptic soil-dwelling habits
  • Growth: Unknown
  • Development: Unknown (Development time unconfirmed for this species)
• Antkeeping:
  • Temperature: Warm and stable, approximately 24-28°C, inferred from subtropical distribution
  • Humidity: Moderate to high, keep nest substrate moist but not waterlogged, inferred from soil-dwelling habits
  • Diapause: Unlikely required, wild colonies fly during winter in Argentina, suggesting year-round activity ^[1]
  • Nesting: Soil-based nests with tight chambers, naturalistic setups or formicarium with narrow passages, inferred from soil-nesting behavior
• Behavior: Specialized termite predators that forage in soil. Cryptic and secretive. Small size requires excellent escape prevention.
• Common Issues: specialized termite diet makes captive feeding extremely difficult, they likely will not accept substitute prey, tiny size means they can escape through minute gaps in lids or mesh, poorly documented biology leaves many care requirements unknown, wild-caught colonies may carry soil-borne pathogens or mites

Termite Predation and Diet

Acanthostichus femoralis is a specialized termite predator. In the wild, they have been found nesting in soil near termite nests, including one colony found near Acromyrmex sp. (leaf-cutting ants) and another series collected with Pheidole sp. ^[1]. They are frequently found under cattle manure, likely using these sites to access termite prey ^[1].

This specialized diet makes them extremely difficult to keep in captivity. You would need a constant supply of live termites. It is unknown whether they will accept other prey items like fruit flies, springtails, or small crickets. Attempting to keep this species without access to termites will likely result in colony failure. If you must attempt captive care, offer small live termites regularly and observe whether the ants hunt them.

Housing and Escape Prevention

These ants nest in soil in nature, often under stones or within cattle manure piles ^[1]. In captivity, provide a naturalistic soil nest or a formicarium with very small, tight chambers.

Workers are only about 3-4mm long and can squeeze through incredibly small gaps. You must use excellent escape prevention. Apply Fluon or baby powder barriers to all container walls, and ensure any ventilation mesh is fine enough to stop 1mm insects. Even small gaps in lid seals will allow escape. They prefer dark, humid conditions with minimal disturbance.

Temperature and Seasonal Patterns

Native to subtropical Argentina and Brazil, these ants likely prefer warm temperatures between 24-28°C. Unlike most temperate ants, Acanthostichus femoralis shows unique seasonal activity. Nuptial flights have been recorded during all months except February, August, and October, including winter months (June, July, September) ^[1].

This suggests they remain active year-round and do not enter a true hibernation or diapause period. Keep them warm consistently throughout the year. A heating cable on one side of the nest can provide a gentle gradient, but avoid overheating as they are soil-dwelling and likely prefer stable, moderate warmth.

Colony Structure and Founding

The colony structure of Acanthostichus femoralis is unknown. They may be monogyne (single queen) or have multiple queens, but this has not been documented. Founding behavior is also unconfirmed. Given their predatory nature, queens may require regular termite prey during the founding stage.

If you acquire a founding queen, offer her small termite prey regularly until workers hatch. The development timeline from egg to worker is unknown. First workers (nanitics) will likely be smaller than subsequent workers and will require immediate access to termite prey. ^[1]

Frequently Asked Questions

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References