Acanthomyrmex dusun

Acanthomyrmex dusun

Acanthomyrmex dusun is a tiny orange-yellow ant found only on the island of Borneo. Major workers measure about 2mm long with noticeably large heads, short downward-curved spines on their backs, and a distinct hollow on top of the head ^[1]. The species lives in submontane forests on Mount Matang in Sarawak, Malaysia ^[2].

This species remains largely a mystery to science. Researchers have only described the major workers, the minor workers, queens, and males have never been documented ^[1]. Based on its close relative Acanthomyrmex careoscrobis, colonies likely stay small with fewer than 100 workers and may have wingless, worker-like queens nesting in twigs or under stones ^[3]. They appear extremely rare in the wild, with just one individual recorded in extensive ground surveys of Bornean forests ^[4].

Quick Summary

• Difficulty: Expert
• Origin & Habitat: Borneo (Sarawak, Malaysia), submontane forests ^[2][1]
• Colony Type: Unknown, likely small single-queen colonies with wingless queens based on related species ^[3]
• Size & Growth:
  • Queen: Unknown, likely worker-sized (wingless) based on Acanthomyrmex careoscrobis ^[3]
  • Worker: Majors ~2mm head width ^[1]
  • Colony: Likely under 100 workers based on related species ^[3]
  • Growth: Unknown
  • Development: Unknown (No development data exists for this species)
• Antkeeping:
  • Temperature: Likely 24-26°C based on tropical Bornean habitat
  • Humidity: High humidity, damp forest floor conditions
  • Diapause: No, tropical species
  • Nesting: Small cavities in dead wood or under stones based on related species ^[3]
• Behavior: Unknown, majors have big heads typical of seed-processing or defense in this genus
• Common Issues: species is virtually unknown in captivity with no documented care records., only major workers described, colony composition and care requirements unconfirmed., extremely rare in nature with limited collection data available., tiny size (2mm) creates high escape risk if housed.

Scientific Mystery and Rarity

Acanthomyrmex dusun represents one of the many ant species known only from a handful of specimens. The original description by Wheeler in 1919 came from a single major worker collected on Mount Matang in Sarawak ^[1]. Moffett redescribed this major worker in 1986,confirming its orange-yellow coloration and distinctive head shape with a well-developed hollow on top ^[1].

Remarkably, no minor workers have ever been described for this species. In most Acanthomyrmex species, majors act as soldiers or food processors while smaller minors handle foraging and nursing. The complete absence of minor worker descriptions suggests either extreme rarity or possibly that minors are genuinely absent or extremely specialized ^[1].

In forest surveys conducted in Bornean dipterocarp forests, researchers encountered this species only once despite extensive daytime ground sampling ^[4]. This extreme rarity makes the species effectively unavailable to antkeepers and means captive care has never been documented.

Natural Nest Preferences

While Acanthomyrmex dusun itself has no documented nest records, its close relative Acanthomyrmex careoscrobis nests in small cavities in dead twigs, rotten wood, under stones, and in leaf litter on the forest floor ^[3]. These ants prefer tight, enclosed spaces with access to high humidity.

If keeping this species (hypothetically), you would want a small naturalistic setup with twigs, small stones, and moist substrate to mimic these microhabitats. The nest chamber should be tiny, remember these are 2mm ants that live in small colonies.

Morphology and the Major Worker

The only known caste of Acanthomyrmex dusun is the major worker, measuring about 2mm in head width with a head length of roughly 2mm ^[1]. These majors show the classic Acanthomyrmex traits: enlarged heads, short cylindrical spines on the back of the thorax that curve downward, and a distinct hollow on the top of the head with a groove running down the face ^[1][2].

The head surface shows scattered small pits, with larger pits near the antenna grooves. The face plate (clypeus) has a noticeable forward projection. The color is orange-yellow throughout ^[1].

Housing and Practical Considerations

Given the complete lack of captive breeding success, any housing advice is theoretical. Based on the species' tiny size and inferred biology, you would need an extremely secure setup. At 2mm, these ants can squeeze through gaps that stop larger species.

A test tube setup with a very fine mesh cover might work initially, though the lack of knowledge about founding behavior means you would not know if a queen needs to forage or seal herself in. Temperature should match Bornean conditions, warm and stable around 24-26°C with high humidity. Feeding would likely involve tiny seeds (as seen in related species) and small insects, but this is speculation. ^[3]

Frequently Asked Questions

References