Acanthomyrmex mizunoi

Quick Summary

• Difficulty: Expert
• Origin & Habitat: Thailand, specifically highland primary hill evergreen forests and coffee plantations at 800-900m elevation in Chiang Rai, Nakhon Nayok, and Nakhon Ratchasima Provinces ^[1].
• Colony Type: Colonies contain both dealate queens and ergatoid (wingless) replacement reproductives ^[1].
• Size & Growth:
  • Queen: Size data unavailable, head measurements (HW 1.98-2.01mm for dealate queens,1.95-2.01mm for ergatoid queens) are provided in literature but total body length is not specified ^[1].
  • Worker: Size data unavailable, head measurements are provided (major workers HW 2.05-2.28mm, minor workers HW 1.02-1.09mm) but total body length is not specified ^[1].
  • Colony: Unknown, likely small to moderate based on soil-nesting habits ^[1].
  • Growth: Unknown
  • Development: Unknown (Development timeline has not been studied. Highland tropical species may develop slowly.)
• Antkeeping:
  • Temperature: Moderate temperatures around 22-25°C, avoid temperatures above 28°C ^[1].
  • Humidity: High humidity required, nest substrate should remain consistently moist but not waterlogged ^[1].
  • Diapause: Unlikely required, this is a tropical highland species from Thailand ^[1].
  • Nesting: Soil-nesting species, use naturalistic soil setups or plaster nests with digging substrate ^[1].
• Behavior: Slow-moving soil-dwelling ants with distinct major and minor worker castes. Minor workers are extremely small and require excellent escape prevention. Major workers are robust with large heads likely used for processing food ^[1].
• Common Issues: minor workers are extremely small and can escape through the tiniest gaps in mesh or lids., highland humidity requirements make them prone to desiccation if the nest substrate dries out., newly described species (2019) means limited care information and potential difficulty sourcing healthy colonies., soil-nesting behavior may make them difficult to observe in standard clear acrylic nests.

Nest Preferences

In nature, Acanthomyrmex mizunoi nests in soil within primary hill evergreen forests at approximately 800 meters elevation ^[1]. They also inhabit coffee plantations at higher elevations around 900 meters in Chiang Rai Province ^[1]. In captivity, provide a naturalistic setup with a deep layer of soil or a plaster nest that allows for digging. They will create small chambers and tunnels where humidity remains stable. Avoid completely dry setups or exposed acrylic nests without substrate, as these highland ants require moist microhabitats. A nest with a soil gradient, damp on one side, slightly less moist on the other, allows the colony to choose their preferred conditions.

Temperature and Humidity

These ants come from the highlands of Thailand at 800-900 meters elevation, not the hot lowlands ^[1]. Keep them at moderate temperatures around 22-25°C. They probably do not need a strong heat gradient, but a gentle warmth on one side of the nest can encourage activity. Avoid temperatures above 28°C as highland species often tolerate heat poorly. Humidity should remain high, keep the nest substrate damp to the touch but not waterlogged. Use a water tower or regular misting to maintain moisture, and ensure good ventilation to prevent mold while keeping humidity up.

Feeding and Diet

Their specific diet has not been studied in detail. Like most related ants in the tribe Crematogastrini, they likely eat small insects and possibly sweet liquids. Offer tiny live prey such as springtails or fruit flies for the minor workers, and slightly larger prey for the majors. Provide sugar water or honey water as a carbohydrate source. Observe what they accept and remove uneaten food promptly to prevent mold in the humid conditions they require. The major workers' large heads suggest they may process hard foods or seeds, so offering small seeds experimentally may be worth trying. ^[1]

Behavior and Temperament

This species shows strong worker dimorphism, majors and minors look quite different and probably serve different roles ^[1]. Major workers have massive heads with dense erect hairs covering the dorsum, and propodeal spines that are broad basally and sharp apically ^[1]. Minor workers have pronotal spines that are shorter than their propodeal spines, and their heads are coarsely punctured ^[1]. They are soil-dwelling and probably move slowly when not disturbed. The minor workers are tiny and can escape easily through standard mesh, so use fine mesh barriers or apply Fluon to the upper outworld walls. They are not known to be aggressive, but the majors can likely bite if threatened.

Ergatoid Queens and Colony Reproduction

Unlike most ants that only produce winged queens, Acanthomyrmex mizunoi colonies contain both normal dealate queens and ergatoid queens ^[1]. Ergatoid queens are wingless reproductive ants that resemble major workers in structure, sculpture, and coloration but possess a median ocellus while lacking lateral ocelli ^[1]. They are slightly smaller than major workers (head width 1.95-2.01mm versus 2.05-2.28mm) ^[1]. These serve as backup breeders, if the primary winged queen dies, an ergatoid queen can activate her ovaries and take over egg-laying duties. This means colonies have a built-in insurance policy against queen loss. However, this does not mean you can combine multiple unrelated queens, the ergatoids are replacement reproductives, not co-founders.

Colony Founding

Founding behavior is unconfirmed for this species. If you obtain a dealate queen, assume she needs peace and quiet in a small, dark chamber with moist substrate. Do not disturb her for several weeks. Provide a test tube with soil or a small plaster chamber. Watch for eggs after several weeks. Expect first workers within several months if conditions are right, though this timeline is completely unconfirmed for this species. ^[1]

Frequently Asked Questions

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References