Metalasius myrmidon

Metalasius myrmidon

Metalasius myrmidon is an exceptionally rare, tiny ant endemic to Greece. Workers measure less than 2mm in total length and are pale yellow throughout, with nearly invisible eyes reduced to just 9 ommatidia or fewer, essentially making them nearly blind. This hypogaeic (ground-nesting) species lives in oak, mixed, and pine forests at mid-altitudes between 540-600 meters, typically nesting under small stones. Their most distinctive features include a complete absence of standing setae on the head and a very dense whitish pubescence covering their pale body. What makes this species particularly interesting is its phylogenetic position, it was recently moved from the genus Lasius to its own genus Metalasius, and is sister to the Prenolepis genus group. This is not a species you'll find in typical antkeeping trade, it's a true collector's piece for those interested in rare Mediterranean fauna.

Quick Summary

• Difficulty: Expert
• Origin & Habitat: Endemic to Greece, found in the Peloponnese, Sterea Ellas, and Thessaly regions at altitudes of 540-600m. Inhabits oak forests, mixed forests, and pine forests ^[1][2]. Nests under small stones in these forest habitats ^[3].
• Colony Type: Colony structure is unconfirmed. Workers are slightly polymorphic (varying in size). This appears to be a monogyne (single-queen) species based on typical Lasius patterns, but this has not been directly documented.
• Size & Growth:
  • Queen: Unconfirmed, queen has not been described in the literature
  • Worker: Workers are very small at HL 0.571-0.619mm, HW 0.500-0.524mm, with total body length under 2mm ^[4][3]
  • Colony: Unknown, no colony size data available in the literature
  • Growth: Unknown, no development data available
  • Development: Unconfirmed, no direct development data exists for this species. Based on typical Lasius patterns and their small size, expect roughly 6-10 weeks at optimal temperature, but this is an estimate. (Development timeline has not been directly studied. Inferring from related Lasius species which typically take 6-8 weeks from egg to worker at room temperature.)
• Antkeeping:
  • Temperature: Keep at room temperature, roughly 20-24°C. This species is from the Mediterranean region of Greece, so moderate warmth is appropriate. A slight gradient allowing cooler areas is recommended.
  • Humidity: Moderate to high humidity, these forest-floor ants prefer damp conditions. Keep the nest substrate consistently moist but not waterlogged. The substrate should feel damp to the touch.
  • Diapause: Likely yes, as a Greek species, they probably experience a mild winter rest period. Reduce temperature to around 10-15°C for 2-3 months during winter.
  • Nesting: Natural nesting is under stones in forest habitats. In captivity, a small test tube setup or small acrylic/plaster nest works well. Given their tiny size and hypogaeic nature, they need a compact nest with small chambers and passages.
• Behavior: These are shy, reclusive ants that spend most of their time underground. Their severely reduced eyes (max 9 ommatidia) indicate they are nearly blind and rely heavily on chemical and tactile cues. Workers are pale yellow and very small. They are not aggressive and likely avoid confrontation. Escape prevention is critical due to their minute size, they can easily slip through standard barrier setups. Expect low activity levels and cryptic behavior.
• Common Issues: escape prevention is critical due to their minute size under 2mm, they will squeeze through tiny gaps that larger ants cannot, this is an extremely rare species with no established captive breeding protocols, wild colonies are the only source, nearly blind workers may have difficulty locating food in open spaces, keep feeding areas contained near nest exits, no colony size data exists, expect small colonies based on their tiny worker size and rarity, hypogaeic species are sensitive to light and vibration, minimize disturbances

Housing and Nest Setup

Metalasius myrmidon is a hypogaeic (ground-dwelling) species that naturally nests under small stones in Greek forest habitats. In captivity, a small test tube setup works well for founding colonies, while established colonies can be moved to a small acrylic or plaster nest. The key requirement is small chambers and narrow passages scaled to their tiny size, workers are under 2mm total length. Keep the nest dark or dimly lit, as these ants have severely reduced eyes and prefer dark conditions. A small outworld connected to the nest allows for feeding space, but ensure it has excellent escape prevention, these tiny ants will slip through standard barriers. The nest substrate should be kept consistently moist but never waterlogged. ^[4][3]

Feeding and Diet

Based on typical Lasiini behavior, these ants likely have a mixed diet similar to other Lasius species, they probably consume honeydew from aphids and small insects. In captivity, offer sugar water or honey water as a constant carbohydrate source. For protein, small live prey like fruit flies or pinhead crickets (cut to appropriate size) should be accepted. Given their tiny size and reduced eyes, place food directly near nest entrances so workers can easily find it. Avoid large prey items they cannot subdue. The pale yellow coloration suggests they may have minimal melanin requirements compared to more pigmented species.

Temperature and Seasonal Care

As a Greek endemic from mid-altitude forests (540-600m), Metalasius myrmidon prefers moderate temperatures in the range of 20-24°C. Room temperature is typically suitable. During winter, they likely experience a mild dormancy period typical of Mediterranean ants, reduce temperatures to around 10-15°C for 2-3 months to simulate their natural seasonal cycle. This species has not been studied in captivity, so observe colony behavior to fine-tune conditions. If workers become sluggish, slightly increase temperature, if they avoid a heated area, reduce it. Avoid temperature extremes. ^[1]

Understanding Their Unique Biology

This species has several remarkable biological features that make it scientifically significant. It was recently moved from the genus Lasius to its own genus Metalasius based on phylogenetic analysis, and is sister to the Prenolepis genus group ^[4]. Workers have compound eyes reduced to just 9 ommatidia or fewer, essentially making them nearly blind compared to typical ants. They also lack a dorsal mandibular groove and lateral hypostomal carina, features that help distinguish them from similar ants. Their body is covered in very dense whitish pubescence, and standing setae are nearly absent from the head. The queen has not been described in the scientific literature, making this one of the most poorly known European ants.

Acquiring This Species

Metalasius myrmidon is an exceptionally rare species that is not available in the antkeeping hobby trade. It is endemic to Greece and has been recorded from only a handful of localities in the Peloponnese, Sterea Ellas, and Thessaly regions. The species was only known from three localities on Evia island until recent surveys documented it in continental Greece ^[5]. There are no established captive breeding protocols, and wild colonies should not be disturbed given their rarity. This species is primarily of interest to researchers and advanced myrmecologists studying Mediterranean ant biodiversity. If you encounter this species for sale, exercise extreme caution, legitimate sources are essentially nonexistent.

Frequently Asked Questions

References