Pseudomyrmex tenuissimus

Quick Summary

• Difficulty: Hard
• Origin & Habitat: Neotropical region from Mexico to Argentina, including Caribbean islands. Inhabits dead twigs and vines in rainforests, forest edges, old fields/pasture, and tropical dry forests ^[1].
• Colony Type: Single-queen colonies (monogyne), based on limited observations. One observed colony contained a single dealate queen and 7 workers, another had 13 workers and 16 alate queens ^[1].
• Size & Growth:
  • Queen: Size data unavailable, no total length measurements are recorded in the research.
  • Worker: Size data unavailable, head width is 0.48-0.53 mm, but total length has not been published ^[2][1].
  • Colony: Observed colonies contain 7-13 workers, maximum colony size unknown but likely remains under 30 workers based on wild records ^[1].
  • Growth: Slow, small colony size and few observations suggest slow population growth.
  • Development: Unknown, no data available. Development times for related Pseudomyrmex species suggest several weeks at tropical temperatures, but this has not been confirmed. (No published data on development.)
• Antkeeping:
  • Temperature: Tropical species, keep between 24-28°C. Do not let temperatures drop below 20°C for extended periods ^[3].
  • Humidity: Moderate to high, keep the nesting area slightly moist but not waterlogged. Mist the outworld occasionally. Provide a humidity gradient with a small water tube in the nest.
  • Diapause: No, this is a strictly tropical ant that does not require hibernation. Maintain warm conditions all year ^[3].
  • Nesting: Twig-nesting species, provide narrow test tubes, Y-tong (AAC) nests, or plaster nests with small, tight chambers. Avoid large, open nests. A test tube setup works well for founding and small colonies.
• Behavior: Calm and non-aggressive. Workers forage individually on vegetation and actively hunt small arthropods. They have good vision and explore their outworld actively. These ants can sting if handled but are not defensive. Escape risk is high due to tiny size, cover all openings with fine mesh (0.3mm or smaller) and seal any gaps.
• Common Issues: tiny size means high escape risk, use fine mesh barriers and seal all gaps., tropical temperature requirements, cannot tolerate cool rooms or temperature drops., very slow colony growth, patience needed, expect only a few workers per year., small colony size makes them vulnerable, minimize disturbances and avoid stressing the colony., founding queens not commonly found, wild colonies are rare, so acquisition may be difficult.

Housing and Nest Setup

Pseudomyrmex tenuissimus naturally nests in dead twigs and vines ^[1]. In captivity, provide narrow, enclosed spaces that mimic this habitat. A test tube with a water reservoir is ideal for founding colonies. For established colonies, use a Y-tong (AAC) nest or a plaster nest with chambers 5-10mm wide, small enough that workers can touch both walls. Avoid large, open nests. Because they are arboreal, position the nest higher up in the setup or attach it to the top of the outworld. Use fine mesh (0.3mm or smaller) on all vents and openings to prevent escapes. Seal even tiny gaps with cotton or silicone, these ants can squeeze through very small spaces.

Feeding and Diet

In the wild, these ants forage on vegetation and hunt small arthropods. They are generalist predators and will accept small prey like fruit flies, pinhead crickets, and tiny mealworm pieces. They also drink sugar water or diluted honey. Offer protein 2-3 times per week in small amounts, any uneaten food should be removed after 24 hours to avoid mold. This species was collected using carbohydrate baits in one study, showing they readily take sugar sources ^[4]. Always provide fresh water via a test tube or small dish.

Temperature and Humidity

Keep the nest at 24-28°C. This is a strictly tropical species ^[3]. If your room is cooler, use a heating cable or heat mat on the side of the nest, not underneath. Humidity should be moderate to high, dampen the nest substrate slightly but avoid waterlogging. A water tube connected to the nest provides drinking water and helps maintain humidity. Mist the outworld if it gets too dry. Good ventilation is important to prevent mold, but keep the nest area humid.

Colony Establishment

Starting a colony is challenging because wild queens are rarely found and colonies are very small. Founding behavior has not been documented, so there is no reliable method for raising a queen. If you acquire a colony, transfer it carefully to a suitable nest. Provide small, dark nesting spaces (test tubes or tiny Y-tong chambers) and keep conditions stable. Expect very slow growth, perhaps adding only a few workers per year. Patience is essential. ^[1]

Behavior and Temperament

Workers are calm and non-aggressive. They forage individually and actively hunt small prey. They have large eyes and good vision ^[1]. Although they can sting (like all Pseudomyrmecinae), they rarely do so unless handled directly. They are not defensive. Because they are so small, they can easily escape, always use fine barriers. Observation is enjoyable as they explore and hunt. They do not form large swarms or use recruitment trails like some ants.

Frequently Asked Questions

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References