Temnothorax ruginosus

Quick Summary

• Difficulty: Medium
• Origin & Habitat: Central and southern China (Hunan, Guizhou, Zhejiang, northern Shaanxi). Found in the Palaearctic region, probably in forest floor microhabitats such as leaf litter, under stones, or in rotting wood – but precise habitat is unrecorded ^[1][2].
• Colony Type: Uncertain – likely single‑queen colonies (monogyne) based on most Temnothorax, but polygyny is possible in some species. No data exists for this species.
• Size & Growth:
  • Queen: Undescribed, inferred from genus patterns, probably ~4‑5 mm (but unconfirmed).
  • Worker: Total length not measured in original description, by comparison with related species, workers are very small, roughly 2–3 mm (inferred). The original description gives mesosoma length 1.80–1.84 mm but no total length ^[1].
  • Colony: Unknown, Temnothorax colonies rarely exceed a few hundred workers. A typical mature colony might hold 50–300 workers (inferred).
  • Growth: Moderate (estimated – exact rate unknown).
  • Development: Unknown for this species, related Temnothorax take about 6–10 weeks at 22‑24°C, but this is an estimate. (Development time depends on temperature and is unconfirmed for T. ruginosus.)
• Antkeeping:
  • Temperature: Keep at room temperature,20‑24°C. Avoid extremes above 30°C or below 5°C. Provide a slight gradient so workers can choose their preferred spot. This is a general recommendation for subtropical/temperate Temnothorax.
  • Humidity: Moderate – nest substrate should be slightly moist but not waterlogged. Their natural habitat is likely mesic (forest floor).
  • Diapause: Likely required for populations from northern Shaanxi (cold winters). A winter rest of 3‑4 months at 5‑10°C is probably beneficial. For southern populations, diapause may be shorter or optional. When in doubt, provide a winter rest.
  • Nesting: Temnothorax naturally occupy pre‑existing cavities: under stones, in hollow twigs, in rotting wood, or in old beetle galleries. In captivity, use a Y‑tong (AAC) nest with small chambers, a test tube setup, or a 3D‑printed nest with narrow passages scaled to the ants’ tiny size.
• Behavior: Peaceful and timid. Like other Crematogastrini, they use a smearing defense – they wipe venom onto enemies rather than injecting it (no sting to human skin). They will flee rather than fight. Foraging is likely solitary. Due to their tiny size, fine escape barriers (e.g.,0.5‑mm mesh, tight seal at connections) are critical.
• Common Issues: tiny size makes escape easy without fine mesh barriers, biology is almost completely unknown – care relies on genus inference, slow colony growth may disappoint beginners expecting rapid development, winter diapause is likely necessary but its exact requirements are unstudied, hard to obtain in the hobby, wild collection in China is illegal

Housing and Nest Setup

Because Temnothorax ruginosus workers are very small, they need tight chambers where they can easily touch all sides. A Y‑tong (AAC) nest with narrow passages works well, as does a simple test tube with a water reservoir. Do not use large open spaces – they stress the colony. The nest should contain small cavities that mimic natural crevices. An outworld area for foraging completes the setup, but escape prevention is vital: use fine mesh (0.5‑mm openings) on ventilation holes and seal all joints with PTFE or fluon. These ants can squeeze through gaps that seem impossible. ^[1]

Feeding and Diet

Like most Temnothorax, T. ruginosus likely accepts small live prey (fruit flies, springtails, pinhead crickets), protein sources (e.g., insect pieces, commercial ant food), and sugar water or honey. Feed protein 2‑3 times per week in small portions – remove uneaten food after 24 hours to prevent mold. Keep a constant supply of sugar water. Adjust portion sizes based on colony size, even a tiny fruit fly can feed several workers.

Temperature and Seasonal Care

Maintain a temperature of 20‑24°C for most of the year. This is a general recommendation for subtropical/temperate Temnothorax. Avoid prolonged heat above 30°C or cold below 5°C. For colonies from northern Shaanxi (cold winters), a winter diapause of 3‑4 months at 5‑10°C is likely necessary. Gradually lower the temperature in autumn, do not feed during deep diapause but keep the nest slightly moist. Increase temperature slowly in spring. For southern populations, a shorter diapause or none might work, but providing a winter rest is safer. ^[1][2]

Behavior and Colony Dynamics

Temnothorax ruginosus is a peaceful, timid species. When threatened, workers try to flee or use a smearing defense – they wipe a venomous secretion onto the enemy without stinging. This is typical of the tribe Crematogastrini. Foraging is solitary, they collect small insects and honeydew. Queens are probably claustral, raising the first brood without leaving the nest. Colony growth is moderate, and mature colonies likely stay under a few hundred workers. ^[1]

Acquisition and Legal Considerations

This species is rarely available in the antkeeping hobby. If you find a captive‑bred colony from a reputable breeder, that is the best source. Do not collect wild queens in China – it is illegal without permits and harms natural populations. Never release any non‑native ant outdoors, this species could become invasive outside its range. Ensure your setup prevents any escape. ^[1]

Frequently Asked Questions

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References