Polyrhachis numeria

Quick Summary

• Difficulty: Unknown, likely Medium to Hard
• Origin & Habitat: Recorded from Tondano (Sulawesi, Indonesia) and the Andaman and Nicobar Islands (India) ^[4][3][1][2]. Natural habitat is unconfirmed but based on related Polyrhachis species it likely inhabits tropical forests, possibly arboreal.
• Colony Type: Unconfirmed, likely monogyne based on typical Polyrhachis patterns
• Size & Growth:
  • Queen: ~7.96 mm ^[1][2]
  • Worker: ~6.50 mm ^[1][2]
  • Colony: Unknown, no colony data exists for this species
  • Growth: Unknown, likely moderate
  • Development: Unknown, estimated 6-10 weeks based on related Polyrhachis species at warm temperatures (No direct development data exists for this species. Estimate based on typical Polyrhachis patterns.)
• Antkeeping:
  • Temperature: Likely needs warm conditions around 24-28°C based on tropical distribution. Provide a temperature gradient.
  • Humidity: Keep the nest substrate consistently moist but not waterlogged, mimicking tropical forest conditions.
  • Diapause: Unknown – tropical species likely do not require a formal hibernation period.
  • Nesting: Polyrhachis (Myrma) species often nest in dead wood or under bark. Use a naturalistic setup with wood pieces or a Y‑tong/plaster nest with good moisture retention.
• Behavior: No captive observations exist. Based on related Polyrhachis species, they are likely moderately active foragers that tend honeydew‑producing insects and hunt small insects. They use formic acid spray as defense (typical Formicinae). Not dangerous to humans. Standard escape prevention for 6–8 mm ants should be adequate.
• Common Issues: no established captive care – keeping this species is experimental., unknown founding success – both natural and captive founding are undocumented., humidity control is critical – tropical species often fail in dry conditions., potential escape risk despite moderate size – use proper barriers., extremely rare in the hobby – obtaining a queen is nearly impossible for most keepers.

Discovery and Taxonomy

Polyrhachis numeria was first described by Frederick Smith in 1861 based on a worker collected by Alfred Russel Wallace in Sulawesi (Tondano) ^[1][2]. In 1927,Karavaiev described a queen from Prinsen Island (Sunda Strait) as Polyrhachis numeria, which Kohout synonymized under P. numeria in 1998 ^[1][2]. The species belongs to the aculeata species-group within the subgenus Myrma and is closely related to Polyrhachis diana from Mindanao, from which it can be separated by its truncate eyes, hairy antennal scapes, and abundant golden body pilosity ^[1][2].

Distribution and Rarity

This species is known from remarkably few specimens. The holotype from Sulawesi remains the only record from that island despite intensive collecting efforts (e.g., Project Wallace,1985) ^[1][2]. Additional records exist from the Andaman and Nicobar Islands (India) ^[3]. The type locality is Tondano, Celebes ^[4]. Male and immature stages remain unknown, and no biological observations have ever been published, making P. numeria one of the most poorly known ant species in the region ^[1][2].

Related Species and Identification

Polyrhachis numeria is most similar to Polyrhachis diana (Wheeler,1909) from Mindanao. Key differences: P. numeria has weakly truncate eyes, numerous short hairs on the antennal scapes, and abundant golden hairs covering all dorsal surfaces. P. diana has normal eyes, bare scapes, and pilosity limited to the front of the head and the underside and tip of the gaster. Additionally, P. numeria has shorter pronotal spines with broad, flat bases, while P. diana has longer, more slender spines ^[1][2]. These features require examination under magnification.

Keeping Polyrhachis numeria in Captivity

No documented captive care exists for this species. Based on the tropical distribution and typical Polyrhachis (Myrma) husbandry, provide warm (24–28°C) conditions and a consistently moist substrate (plaster or Y‑tong nest). Founding is likely claustral – the queen seals herself in and lives on stored fat. Feed sugar water and small insects (fruit flies, small mealworms). This species is experimental: keepers will be pioneering its care. No published observations on behavior, growth, or reproduction are available.

Morphology and Physical Characteristics

Workers measure about 6.5 mm in total length, queens about 8 mm ^[1][2]. Distinctive features include weakly truncate eyes, numerous short hairs on the superior edge of the antennal scapes, and abundant golden hairs covering all dorsal body surfaces. The pronotal spines are relatively short with broad, flat bases ^[1][2]. These characteristics are useful for identification but have no direct implications for captive care.

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