Polyrhachis thusnelda

Quick Summary

• Difficulty: Medium
• Origin & Habitat: Northern Queensland, Australia, from Cape York Peninsula south to Mackay. Found in open eucalypt forests and occasionally in lowland tropical rainforest canopies ^[1].
• Colony Type: Unconfirmed, no specific data on queen number.
• Size & Growth:
  • Queen: 9.47-10.18 mm ^[1]
  • Worker: 8.16-9.12 mm ^[1]
  • Colony: Unknown, no colony size data available
  • Growth: Moderate, inferred from genus patterns
  • Development: Estimated 8-12 weeks at optimal temperature based on genus patterns (Pupae develop in cocoons, which requires appropriate humidity)
• Antkeeping:
  • Temperature: Keep at 24-28°C. As a Queensland species, they need warm conditions year-round.
  • Humidity: Keep nest substrate consistently moist but not waterlogged, as lithocolous species prefer stable conditions.
  • Diapause: Unknown, no data on diapause requirements.
  • Nesting: Lithocolous (rock-dwelling) species. Provide tight rock crevices or similar tight chambers. Y-tong (AAC) nests work well ^[3].
• Behavior: Generally calm. They lack a functional sting and instead spray formic acid as a defense mechanism. Workers are moderately active foragers. Escape risk is moderate due to their size.
• Common Issues: colonies may fail if kept too cold, maintain warm temperatures year-round, lithocolous species need tight, dark nesting spaces, they may reject open formicaria, pupae in cocoons require stable humidity to develop properly, too dry causes desiccation, newly established colonies are sensitive to disturbance, minimize nest inspections during founding, wild-caught colonies may have parasites or diseases that cause colony failure

Housing and Nest Preferences

Polyrhachis thusnelda is a lithocolous species, meaning it naturally nests in rock crevices and similar tight spaces ^[3]. In captivity, they do best in nests that mimic these conditions, dark, secure chambers with minimal light exposure. Y-tong (AAC) nests work well because they provide the tight, enclosed spaces these ants prefer. Naturalistic setups with flat stones or slate pieces can also work, but ensure there are no large gaps that let in too much light. Avoid fully transparent acrylic nests unless you can cover them, these ants will often refuse to inhabit overly bright chambers.

Feeding and Diet

Like most Polyrhachis species, P. thusnelda is omnivorous with a preference for sweet liquids and protein. In captivity, offer sugar water or honey as a constant energy source. For protein, provide small insects like fruit flies, small crickets, or mealworms. Feed protein sources 2-3 times per week, removing any uneaten prey after 24 hours. Keep sugar water available at all times, replacing every few days to prevent mold.

Temperature and Seasonal Care

Being from Queensland, Australia, these ants need warm conditions to thrive. Maintain temperatures between 24-28°C during the active season. A heating cable or mat on one side of the nest creates a temperature gradient that allows the colony to self-regulate. During the Australian winter, you can reduce temperatures to around 18-20°C for 2-3 months if the colony shows reduced activity, but avoid true cold hibernation.

Growth and Development

Polyrhachis thusnelda workers develop in cocoons, which is important for their care ^[3]. This means you need to ensure adequate humidity in the nest, too dry and the pupae will desiccate, too wet and they may mold. The exact development time from egg to worker is not documented, but based on related Polyrhachis species, expect around 8-12 weeks at optimal temperatures. Growth rate is moderate, and colonies build gradually over the first year.

Behavior and Temperament

Polyrhachis thusnelda is generally a calm species. They lack a functional sting and instead spray formic acid from an acidopore as a defense mechanism. Workers are moderately active and will explore the outworld regularly in search of food. They are not known for being particularly good climbers or escape artists relative to their size, so standard barrier methods should be sufficient.

Frequently Asked Questions

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References