Polyrhachis schoopae

Polyrhachis schoopae

Polyrhachis schoopae is an Australian ant species belonging to the subgenus Chariomyrma. Workers are medium-sized ants with the characteristic spines on their thorax that give Polyrhachis their common name of 'spiny ants.' They were originally described as a subspecies of P. appendiculata in 1902 and raised to full species status in 1990 . This species is found exclusively in Australia, particularly in the Queensland region. Like other Chariomyrma species, they nest in rock crevices and on rock faces, using silk to help construct their nests. They are part of the Formicinae subfamily, meaning they defend themselves by spraying formic acid rather than stinging.

Quick Summary

• Difficulty: Medium
• Origin & Habitat: Australia, specifically Queensland wet tropics region. They are lithocolous (rock-dwelling) ants that nest in abandoned nests of other Polyrhachis species, particularly P. turneri, on rock faces ^[1][2].
• Colony Type: Likely single-queen colonies (monogyne) based on typical Polyrhachis genus patterns. Colony structure specific to this species is unconfirmed.
  • Colony: Monogyne
  • Founding: Claustral
• Size & Growth:
  • Queen: Estimated 8-12mm based on typical Polyrhachis queen size range
  • Worker: Estimated 5-9mm based on typical Polyrhachis worker size range
  • Colony: Unknown for this specific species, related Polyrhachis species typically reach several hundred workers
  • Growth: Moderate, estimated based on genus-level data
  • Development: Estimated 6-10 weeks at optimal temperature based on related Formicinae species (Development time is estimated from genus-level data since specific development has not been studied for this species)
• Antkeeping:
  • Temperature: Keep at 24-28°C. Being from the Queensland wet tropics, they prefer warm, stable conditions. A heating cable on one side of the nest can create a gentle gradient if room temperature is insufficient.
  • Humidity: Moderate to high humidity around 60-80%. Mist the outworld occasionally and keep the nest substrate slightly moist but not waterlogged. They come from a subtropical climate with regular rainfall.
  • Diapause: Unconfirmed, Australian Polyrhachis species from Queensland may reduce activity in cooler months but true hibernation is not typical in their range. Consider reducing temperatures slightly (to around 20-22°C) during winter months.
  • Nesting: Lithocolous (rock-dwelling) species. They naturally nest in rock crevices and on rock faces, often using abandoned nests of other Polyrhachis species. In captivity, a naturalistic setup with flat stones or a Y-tong/plaster nest with rough surfaces works well. They use silk in nest construction, so providing materials they can work with is beneficial.
• Behavior: Generally docile and non-aggressive compared to many ant species. They are active foragers but not particularly territorial. Workers are medium-sized and can climb smooth surfaces, so standard escape prevention (fluon on rim edges) is recommended. As Formicinae, they can spray formic acid when threatened, though they are not considered dangerous to humans.
• Common Issues: colonies may fail if kept too dry, their rock-dwelling nature means they prefer stable moisture conditions, slow founding phase, claustral queens can take months to raise first workers, and beginners may give up too soon, wild-caught colonies may have parasites that can decimate the colony in captivity, escape prevention is needed, workers can climb glass and smooth surfaces

Housing and Nest Setup

Polyrhachis schoopae is a lithocolous species, meaning they naturally nest in rock crevices and on rock faces. In captivity, you can use a naturalistic setup with flat stones placed on moist substrate, which mimics their natural rock-dwelling habitat. Alternatively, a Y-tong (AAC) nest or plaster nest with rough-textured chambers works well. The key is providing a nest environment that feels like rock, they don't do well in smooth, glass-walled nests alone. Add some small rocks or rough surfaces inside the formicarium for them to work with. Because they use silk in nest construction, you might include some loose soil or fine materials they can manipulate. ^[1][2]

Feeding and Diet

Like other Polyrhachis species, P. schoopae is omnivorous. They readily accept sugar sources (honey water, sugar water) and protein (small insects like fruit flies, mealworms, crickets). In the wild, they forage for honeydew from aphids and scale insects, plus small arthropods. Feed them a varied diet: offer sugar water constantly and protein prey 2-3 times per week. Remove uneaten prey after 24 hours to prevent mold. They are not specialized predators, so any appropriately-sized live or frozen prey works.

Temperature and Seasonal Care

Being from the Queensland wet tropics of Australia, these ants need warm conditions. Keep the nest area at 24-28°C for optimal brood development. A heating cable placed on top of the nest (never underneath, as this can dry out the nest too quickly) can help maintain warmth. During the cooler winter months, you can reduce temperatures slightly to around 20-22°C, but avoid true cold hibernation since they come from a subtropical climate. They may become less active in winter but should not be allowed to experience cold stress below about 18°C.

Behavior and Colony Dynamics

Polyrhachis schoopae is a relatively docile species that establishes moderate-sized colonies. Workers are active foragers and will readily explore the outworld for food. They have the characteristic spines on their thorax that help distinguish them from other ant genera. When threatened, they can spray formic acid as a defense mechanism, this is harmless to humans but can deter predators. Colonies grow gradually over several months to years, with the queen laying eggs continuously once workers are established. The founding phase can be slow, so patience is key when establishing a new colony from a queen.

Frequently Asked Questions

References