Strumigenys benten

Quick Summary

• Difficulty: Hard
• Origin & Habitat: Japan and Taiwan. Nests at margins of broadleaf forests and adjacent open land, in soil or under stones ^[1]. Almost exclusively found in forests, but also in a few parks in Hiroshima ^[3].
• Colony Type: Unconfirmed, one documented colony contained over 150 workers ^[1].
• Size & Growth:
  • Queen: Unknown, no measurements available.
  • Worker: 2.1-2.6 mm total length (TL) ^[1].
  • Colony: Up to at least 150 workers ^[1].
  • Growth: Unknown, no studies on colony growth.
  • Development: Unknown, no specific data for this species. (Inferred from related Strumigenys species, but unconfirmed.)
• Antkeeping:
  • Temperature: Keep at moderate room temperature, around 20-24°C. They originate from temperate Japan and Taiwan, so they do not require extreme heat ^[1].
  • Humidity: High humidity required. Keep the nest substrate consistently moist but not waterlogged, mimicking forest floor litter ^[3].
  • Diapause: Likely required given temperate distribution. Reduce temperature to around 10-15°C for 2-3 months in winter.
  • Nesting: Natural nests in soil or under stones ^[1]. In captivity, use a naturalistic setup with moist soil/sand mix, or a plaster nest with small chambers. Keep the nest dark and humid.
• Behavior: Specialized predators of springtails (Collembola). Non-aggressive and shy toward keepers. Workers are tiny (under 3 mm) and can escape through very small gaps, escape prevention is critical. They are slow-moving and prefer darkness. Colonies are small and sensitive to disturbance.
• Common Issues: extreme escape risk due to tiny size, workers can squeeze through standard test tube cotton and small gaps., specialized diet requires live springtail cultures, they will not survive on standard ant foods., high humidity needs mean desiccation is a major risk, substrate must stay consistently moist., colonies are small and may decline if disturbed too often., development timeline and optimal conditions are unknown, making care experimental.

Housing and Nest Setup

Strumigenys benten require a high-humidity, dark nest. A naturalistic setup with a shallow container filled with moist forest floor substrate (mix of soil, sand, and leaf litter) mimics their natural habitat ^[1]. A small plaster nest with tight chambers and a water reservoir can also work, but ensure chambers are appropriately sized. For founding colonies, use a test tube setup with tightly packed cotton or foam to prevent escapes. Cover the nest to maintain darkness and humidity ^[1][3].

Feeding and Diet

Strumigenys benten are specialized predators that primarily hunt springtails (Collembola) in the wild. In captivity, you must provide live springtails as their main food source, this is essential for their survival. Springtails can be cultured separately on moist charcoal or soil and added to the colony. Other tiny arthropods like booklice (Psocoptera) may be accepted, but springtails should form the bulk of their diet. Sugar sources are not accepted, they are obligate predators. Do not feed standard ant foods like mealworms or honey water. Their hunting behavior using trap-jaw mandibles is fascinating to observe.

Temperature and Seasonal Care

Maintain moderate temperatures, around 20-24°C. They originate from temperate Japan and Taiwan, so they do not require extreme warmth ^[1]. In winter, they likely require a diapause period. Based on their temperate distribution, reduce temperature to around 10-15°C for 2-3 months to simulate winter conditions. The exact requirements are unconfirmed, so observe colony behavior. Avoid overheating or rapid temperature fluctuations.

Behavior and Colony Dynamics

Strumigenys benten colonies are small, with one documented wild colony reaching over 150 workers ^[1]. They are shy and non-aggressive, preferring to hide. Workers hunt individually through leaf litter, using their trap-jaw mandibles to capture springtails. Activity may increase at dusk and during the night. These ants are not defensive and are harmless to keepers. However, their tiny size makes them easy to lose during maintenance, handle with extreme care. Colonies may be slow to expand initially.

Finding and Acquiring Colonies

Strumigenys benten is uncommon in Japan ^[4]. It is found almost exclusively in forests, at forest margins and in leaf litter ^[3]. In Japan, it has been collected from southern Honshu through Kyushu and the Ryukyu Islands ^[1]. The most reliable method to obtain colonies is by searching under stones in forested areas, especially at forest edges, and using Berlese funnel extraction from leaf litter. Wild-caught colonies may be stressed, quarantine and careful observation are essential. They are rarely available in the antkeeping trade due to their specialized needs.

Frequently Asked Questions

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References