Aphaenogaster rugulosa

Quick Summary

• Difficulty: Medium
• Origin & Habitat: Japan (Ryukyu Islands), nesting in woodland soil ^[3][1]
• Colony Type: Likely single-queen colonies based on typical Aphaenogaster patterns
• Size & Growth:
  • Queen: size data unavailable, inferred from Aphaenogaster genus (~7-9 mm)
  • Worker: around 5 mm ^[1]
  • Colony: up to 600 workers ^[2]
  • Growth: Moderate
  • Development: 6-10 weeks at 25°C (estimated from related Aphaenogaster species) (Development speed varies with temperature, first workers may emerge slightly faster)
• Antkeeping:
  • Temperature: 20-25°C during active season, with winter cooling to 10-15°C for 2-3 months (inferred from subtropical origin at 26°N latitude ^[3])
  • Humidity: Moderate to high, keep nest soil damp like woodland floor conditions ^[1]
  • Diapause: Yes, likely required, cool period mimicking Ryukyu winter
  • Nesting: Soil or plaster nests with digging substrate, naturalistic woodland setups work best ^[1]
• Behavior: Moderate activity level with unique defense behaviors. Workers play dead (death-feigning) when disturbed and curl their gasters under while foraging ^[1]. They are peaceful and rarely sting. Their 5 mm size means standard escape prevention works well ^[1].
• Common Issues: workers playing dead can be mistaken for mortality, check for thanatosis before removing motionless ants, require consistent protein sources alongside sugars due to trophic egg feeding habits ^[2], soil-nesting species may struggle in purely acrylic setups without appropriate substrate, subtropical origin means they need stable conditions without extreme heat or cold drafts

Nest Preferences

In the wild, Aphaenogaster rugulosa nests in soil within woodlands and along forest margins ^[1]. They prefer structured soil environments with some moisture retention. In captivity, provide a naturalistic setup with a soil or plaster nest that allows digging behavior. A test tube setup works for founding queens, but mature colonies need space to excavate. Use a nest material that holds moisture without becoming waterlogged, think damp forest floor, not swamp ^[1].

Feeding and Diet

These ants use a mix of solid prey and special trophic eggs to feed their larvae ^[2]. Workers lay non-viable trophic eggs specifically as a protein source for the brood alongside solid food ^[2]. Offer small insects like fruit flies, springtails, or tiny pieces of mealworm. Provide sugar water or honey for energy. The combination of solid prey and trophic eggs means they need consistent protein availability, do not rely only on sugar sources ^[2].

Temperature and Seasonal Care

Coming from Japan's Ryukyu Islands at 26°N latitude, these ants experience mild subtropical conditions ^[3]. Keep them at 20-25°C during the active season. They likely need a winter rest period (diapause) at 10-15°C for 2-3 months to simulate the cooler Ryukyu winter. Without this cooling period, colonies may slow down or fail to thrive long-term. Use a heating cable on one side of the nest to create a gradient, but ensure the nest does not dry out.

Behavior and Temperament

Workers show two interesting behaviors observed in Japanese field studies. First, they practice death-feigning (thanatosis), freezing and playing dead when threatened ^[1]. Second, they perform a gastral turn-down while foraging, curling their abdomen underneath their body ^[1]. They are generally peaceful and not prone to stinging. Their 5 mm size means they can use standard barriers but will not squeeze through extremely tiny gaps like smaller species ^[1].

Intercastes and Colony Composition

Research on this species discovered something unusual: intercastes ^[2]. These are rare individuals (about 0.1% of the colony) that look halfway between workers and queens ^[2]. They have wing buds, intermediate body sizes, and mixed traits, some have queen-like eyes with worker-like bodies, or vice versa ^[2]. One colony had three intercastes together ^[2]. These do not function as queens (they lack full reproductive organs) but show the flexibility of this species' development ^[2]. You probably will not see them, but they are a unique feature of this species.

Frequently Asked Questions

Report an Issue

The current care sheet is based fully on literature. See inconsistencies, or something that's incorrect? Please report here, it will be resolved after review from an admin. Contributing to the blogs tab also helps providing information, to make us be able to further improve the caresheets. Thank you for your support!

References