Scientific illustration of Polyrhachis capeyorkensis ant - showing key identification features including head, thorax, and gaster.

Polyrhachis capeyorkensis

Non-Parasitic Queen No Gamergate
Sci. Name
Polyrhachis capeyorkensis
Subgenus
Hagiomyrma
Tribe
Camponotini
Subfamily
Formicinae
Author
Kohout, 2013
Distribution
Found in 0 countries

Introduction

Polyrhachis capeyorkensis is a medium-to-large ant species native to Cape York Peninsula in Queensland, Australia. Workers measure 6.50-7.81 mm in total length with a distinctive reddish-brown to rusty red coloration . The body is covered in bristle-like hairs, and like other Polyrhachis species, they have spines on the propodeum and petiole, earning them the common name 'spiny ants'. The pronotal humeri are narrowly rounded, and the petiole bears a pair of divergent, weakly downturned spines . This species belongs to the schenkii species-group within the subgenus Hagiomyrma . Very little is known about this species' biology in the wild. It was described in 2013 and is known only from worker caste specimens . Based on its tropical Australian distribution, it likely lives in forested habitats and may be active year-round in its warm native range. The complete lack of documented biology means this is a species for patient, experienced keepers who enjoy observing and learning from their colonies rather than following established care protocols .

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Status by country, from Kass et al. 2022 & Wong et al. 2023

Native Invasive Introduced (indoor) Intercepted Unknown
Data Sources
Year Range 2000 - 2026

Quick Summary

  • Difficulty: Expert
  • Origin & Habitat: Cape York Peninsula, Queensland, Australia, tropical northern Australia. The specific habitat type is unknown, but related Polyrhachis species in Australia typically inhabit forested areas, often nesting in soil under stones or in rotting wood [1][2].
  • Colony Type: Unknown. Colony structure (single-queen or multi-queen) has not been documented for this species. Polyrhachis species vary widely in their colony structure, with some being single-queen and others forming multi-queen colonies [1].
  • Size & Growth:
    • Queen: Unknown, queen caste has not been described [1].
    • Worker: 6.50-7.81 mm total length [1].
    • Colony: Unknown, no colony size data exists for this species [1].
    • Growth: Unknown, development has not been studied. Based on size and related Polyrhachis species, growth is likely moderate.
    • Development: Unknown. Based on typical Polyrhachis patterns and tropical location, it is estimated to take 6-10 weeks from egg to worker at warm temperatures, but this is a rough guess. (No direct development data exists. Related Polyrhachis species typically take several months from egg to adult worker.)
  • Antkeeping:
    • Temperature: Keep warm, roughly 24-28°C. Cape York Peninsula has a tropical climate with year-round warmth. Provide a temperature gradient so ants can choose their preferred zone [2].
    • Humidity: Keep nest substrate consistently moist but not waterlogged, with some drier areas available. Tropical northern Australia is warm and humid for most of the year [2].
    • Diapause: No. As a tropical species from far northern Australia, they remain active year-round without a true hibernation period [2].
    • Nesting: Likely prefers naturalistic setups with soil or rotting wood. Related Polyrhachis species often nest under stones or in decaying wood. A Y-tong or plaster nest with moderate chamber sizes would be appropriate. Provide a foraging area with substrate they can burrow into [2].
  • Behavior: Not documented. Based on related Polyrhachis species, they are likely moderately active foragers with a generally non-aggressive temperament. They probably forage individually or in small groups rather than forming large raiding columns. Their moderate size means they can defend themselves but are not particularly aggressive toward keepers. Escape prevention should be moderate, they are large enough that standard barriers work well, but always use proper containment [2].
  • Common Issues: completely unknown biology means standard antkeeping assumptions may not apply., no documented queen or colony structure, you may be starting completely blind., growth rate is unconfirmed, patience will be required., humidity and temperature preferences are inferred, not confirmed., risk of keeping a species with no established captive care history.

Why This Species Is Challenging

Polyrhachis capeyorkensis is not a species for beginners. It was only described in 2013,and absolutely no biological data exists for it in scientific literature [1]. This means there are no established care protocols, no documented development times, no confirmed temperature or humidity preferences, and no information on colony structure or founding behavior. Every antkeeper who succeeds with this species will be essentially pioneering captive husbandry for it. You should only attempt this species if you are an experienced antkeeper with several successful colonies already, and you have the patience to experiment and learn from failures. The complete lack of information means you are essentially conducting your own research project with each colony [1].

Inferring Care from Related Species

Since direct data is unavailable, we can make educated guesses based on what is known about Polyrhachis genus behavior and this species' native habitat. Polyrhachis is a large genus with over 700 species, mostly tropical and subtropical. Many are arboreal or ground-nesting, and some known as 'weaver ants' can construct nests from leaves held together with silk, though not all species exhibit this behavior. Cape York Peninsula is tropical far-northern Australia, so these ants are adapted to year-round warmth and high humidity. Related Australian Polyrhachis species typically nest in soil under stones or in rotting wood on the forest floor. Start with a warm, humid setup and observe your colony's behavior, if they avoid certain areas or cluster in specific spots, adjust accordingly [2].

Housing Recommendations

Given the complete lack of species-specific data, recommend a naturalistic or semi-naturalistic setup that allows for experimentation. A Y-tong nest or plaster nest with connected foraging area works well. The nest chambers should be appropriately sized for workers of 6.50-7.81 mm, not too tight, but not excessively spacious either. Provide a moisture reservoir to maintain humidity, and consider adding a layer of soil or fine substrate in the foraging area to allow for natural digging behavior if they want it. Temperature can be maintained with a heating cable on one side of the nest, creating a gradient from roughly 24°C to 28°C. Use standard escape prevention, these are large enough that standard barriers are effective [2].

Feeding and Diet

Polyrhachis species are typically omnivorous, feeding on honeydew, nectar, and small insects. Without specific data for P. capeyorkensis, offer a standard ant diet: sugar water or honey as a constant energy source, and protein sources like mealworms, small crickets, or other insects. Start with small prey items and observe feeding behavior. Since nothing is known about their dietary preferences, be prepared to experiment. Some Polyrhachis species prefer sweet liquids while others are more predatory. If your colony does not accept certain foods, try alternatives. Remove uneaten prey after 24-48 hours to prevent mold [2].

Observation and Record-Keeping

Because so little is known about this species, your observations are potentially valuable to the antkeeping community. Keep detailed records of your colony's behavior, preferred temperatures, humidity levels, feeding acceptance, growth rates, and any other notable observations. Document when workers emerge, how quickly the colony grows, what foods they prefer, and how they interact with their environment. This information, if shared, could help establish proper care protocols for this species in the future. Consider joining antkeeping forums or communities where you can share your findings with others attempting to keep this species [1].

Frequently Asked Questions

How difficult is Polyrhachis capeyorkensis to keep?

This is an expert-level species. It was only described in 2013 and has absolutely no documented biology in scientific literature [1]. There are no established care protocols, no confirmed temperature or humidity requirements, and no information on colony structure. Only experienced antkeepers should attempt this species, and they should be prepared for a learning process with no guaranteed success.

What do Polyrhachis capeyorkensis ants eat?

While not specifically documented for this species, Polyrhachis ants are typically omnivorous. Offer sugar water or honey as a constant energy source, and protein like small insects (mealworms, crickets). You may need to experiment to determine their preferences, some related species prefer sweet liquids while others are more predatory [2].

What temperature should I keep Polyrhachis capeyorkensis at?

Since this is a tropical species from Cape York Peninsula in northern Australia, keep them warm. Aim for 24-28°C with a temperature gradient so they can choose. A heating cable on one side of the nest can create this gradient. This is an estimate based on their native habitat, not confirmed requirements [2].

Do Polyrhachis capeyorkensis ants need hibernation?

No. As a tropical species from far-northern Australia, they are likely adapted to year-round warmth and do not require hibernation [2].

How big do Polyrhachis capeyorkensis colonies get?

Unknown. No colony size data exists for this species [1]. Based on worker size and related Polyrhachis species, colonies likely reach several hundred workers over time, but this is purely speculative.

How long does it take for Polyrhachis capeyorkensis to produce first workers?

Unknown. No development data exists for this species. Based on typical Polyrhachis patterns and their tropical distribution, it is estimated to take roughly 6-10 weeks from egg to worker at warm temperatures, but this is a very rough guess [2].

Can I keep multiple queens of Polyrhachis capeyorkensis together?

Unknown. Colony structure has not been documented for this species. Polyrhachis species vary, some are single-queen, others are multi-queen. Without data, do not attempt combining unrelated foundress queens [1].

What size nest do I need for Polyrhachis capeyorkensis?

Use a nest with chambers appropriately sized for workers of 6.50-7.81 mm. A Y-tong or plaster nest with moderate chamber sizes works well. They are large enough that tiny gaps are not a major concern, but standard escape prevention is still recommended [1].

Where is Polyrhachis capeyorkensis native to?

Cape York Peninsula in Queensland, Australia. This is the very northern tip of Australia, a tropical region with warm temperatures year-round. The specific habitat type within this region is unknown [1].

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References

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This caresheet is licensed under CC BY-SA 4.0 .