Nesomyrmex cataulacoides

Nesomyrmex cataulacoides

Nesomyrmex cataulacoides is a remarkably unusual ant species known for its bizarre morphology. Workers are tiny at just 1.7-1.9mm total length, with a distinctive appearance that actually led to its name, it resembles ants in the genus Cataulacus so strongly that it was originally described there. The most striking features are the pairs of large spines on both the petiole and postpetiole (the two waist segments), along with well-developed propodeal spines. Unlike most Nesomyrmex species, they have 11-segmented antennae instead of the typical 12. They are completely smooth on top with no standing hairs. This species is strictly arboreal, meaning it lives high in the forest canopy rather than on the ground ^[1].

Quick Summary

• Difficulty: Unknown, likely Advanced
• Origin & Habitat: Found in Cameroon and Kenya in Central Africa. Strictly arboreal, in the wild, colonies have been collected from inside the plant cavities of Leonardoxa africana, a myrmecophyte (plant that houses ants) ^[2].
• Colony Type: Colony structure is unconfirmed. Based on related Nesomyrmex species and the single-queen founding observation from the type specimen, likely single-queen (monogyne) colonies. Maximum colony size is unknown but likely small (under 200 workers) given their arboreal plant-cavity nesting habit.
• Size & Growth:
  • Queen: Unknown, queen has not been described
  • Worker: 1.73-1.85mm total length (HL 0.58-0.60mm, HW 0.54-0.56mm)
  • Colony: Unknown, likely under 200 workers based on typical arboreal plant-cavity nesting
  • Growth: Unknown, likely slow to moderate based on small colony size
  • Development: Unknown, estimated 6-10 weeks based on typical Myrmicinae patterns at warm temperatures (No direct development data exists. Estimates based on related genera and small colony size suggest moderate development time.)
• Antkeeping:
  • Temperature: Unknown, start around 24-26°C and observe colony activity. As an African arboreal species, they likely prefer warm, stable conditions. Adjust based on behavior.
  • Humidity: Likely high humidity (70-85%), they nest inside living plants which maintain consistent moisture. Keep nest substrate consistently moist but not waterlogged.
  • Diapause: Unknown, African species from equatorial regions may not require formal hibernation, but may have reduced activity periods. No data on overwintering requirements.
  • Nesting: Must provide arboreal-style nesting. In captivity, they do well in small acrylic or Y-tong nests with tight chambers scaled to their tiny size. The key is providing a humid, enclosed space similar to plant cavity internodes. Avoid large open spaces.
• Behavior: Behavior is poorly documented. They are strictly arboreal and likely very shy, avoiding confrontation. Their distinctive spines may serve as defense. Workers are tiny and likely escape through standard barriers, use fine mesh. Foraging style unknown but likely generalist like other Nesomyrmex. Their bizarre morphology with multiple spines is unique within the genus and makes them visually striking in captivity.
• Common Issues: escape prevention is critical, at under 2mm total length, they can squeeze through tiny gaps that larger ants cannot, no development data exists, beginners may struggle with unknown requirements, humidity control is challenging, arboreal species need consistent moisture without flooding, colony may remain very small, don't expect large colonies like ground-nesting species, wild-caught colonies are extremely rare, most available stock will be from limited breeding

Housing and Nest Setup

Nesomyrmex cataulacoides requires arboreal-style housing. In the wild, they live inside plant cavities in the canopy, specifically documented from inside Leonardoxa africana. This means you should provide a small, humid nest with tight chambers scaled to their tiny 2mm size. Acrylic nests or Y-tong nests work well, avoid large formicarium spaces designed for bigger ants. The nest should have a water reservoir to maintain humidity, as these ants need consistent moisture. Because they are strictly arboreal, they do not need a large outworld, a small foraging area is sufficient. Use excellent escape prevention: their tiny size means they can slip through gaps that larger ants cannot, so use fine mesh and check all connections carefully ^[1].

Feeding and Diet

Diet is unconfirmed for this specific species, but Nesomyrmex generally are omnivorous like typical Myrmicinae. Based on related species, they likely accept sugar sources (honey, sugar water) and protein (small insects like fruit flies, pinhead crickets, or mealworms). Being so small, their prey items should be appropriately sized, tiny insects are more natural than large prey. Feed small amounts of protein 2-3 times per week and provide a constant sugar source. Remove uneaten food to prevent mold. Since their natural nesting plant (Leonardoxa africana) produces extrafloral nectaries, they likely have access to plant sugars in the wild, consider providing occasional honey or sugar water ^[2].

Temperature and Humidity

Temperature requirements are not documented, but as an African species from Cameroon and Kenya, they likely prefer warm conditions. Start around 24-26°C and observe your colony, if workers are clustered near the heat source, increase slightly, if they avoid it, reduce. Avoid temperature extremes. Humidity is more critical, as an arboreal species nesting inside living plants, they need high humidity (70-85%). The nest substrate should feel consistently moist but never waterlogged. A water tube or reservoir connected to the nest helps maintain humidity. Monitor for condensation, some condensation is good, but standing water indicates too much moisture. Room temperature in most homes (20-24°C) may be too cool, consider a gentle heat gradient using a heating cable on one side of the nest ^[1].

Colony Establishment

Establishing this species in captivity is challenging because they are rarely kept and poorly understood. Queens have not been described scientifically, so founding colonies from wild-caught queens is extremely difficult. If you obtain a colony, expect slow growth, their tiny size and likely small colony maximum means you won't see the rapid expansion seen in species like Lasius or Camponotus. The unique morphology (spines on petiole and postpetiole) makes them visually distinctive and interesting to observe, but their cryptic arboreal lifestyle means you'll see less activity than ground-nesting species. Be patient with slow development and avoid disturbing the nest during founding ^[1].

Frequently Asked Questions

References