Temnothorax sordidulus

Quick Summary

• Difficulty: Medium
• Origin & Habitat: Dinaric Alps (Austria, Croatia, Slovenia) and surrounding Balkan regions, with isolated records in France. Found at altitudes from 40 m ^[6] to 2250 m ^[2] in warm, dry habitats with sparse vegetation, typically on exposed limestone or dolomite rocks ^[7][4][5].
• Colony Type: Monogyne, single-queen colonies. Multiple queens may found colonies together (pleometrosis), but only one remains as functional queen ^[4]. Ergatoid replacement reproductives have not been documented.
• Size & Growth:
  • Queen: ~4-5 mm (inferred from Temnothorax genus)
  • Worker: ~2-3 mm (inferred from Temnothorax genus)
  • Colony: Likely under 500 workers (typical for small Temnothorax species)
  • Growth: Moderate
  • Development: 6-10 weeks (estimated based on related Temnothorax species) (Development speed depends on temperature, faster at 24-26 °C.)
• Antkeeping:
  • Temperature: Keep warm around 22-26 °C. This species nests in sun-exposed rock crevices and prefers high temperatures ^[5]. Provide a temperature gradient so workers can choose their preferred warmth.
  • Humidity: Low to moderate. Keep the nest relatively dry with good ventilation. These ants come from dry, well-drained rocky sites. Let the substrate dry out between waterings to prevent mold.
  • Diapause: Yes, as a temperate species, a winter diapause is likely required. Many keepers recommend 2-3 months at 5-10 °C. This is typical for central European Temnothorax.
  • Nesting: Nests in tight rock crevices or dead wood in nature ^[4][5]. In captivity, use a Y-tong (AAC) or plaster nest with small chambers. Provide narrow passages scaled to their tiny size. A dry, ventilated setup with flat stones can also work. Avoid damp, mold-prone containers.
• Behavior: Temnothorax sordidulus is a peaceful, non-aggressive species. Workers are small and slow-moving. They have a modified stinger adapted to smear venom onto enemies (common in Crematogastrini) rather than piercing, harmless to humans. Not escape‑prone due to small size, but standard escape prevention is still recommended. Foraging is typical for Temnothorax: individual workers search for small prey and honeydew. They do not swarm aggressively.
• Common Issues: difficulty replicating their natural hot, dry rock crevice habitat, too much humidity kills them., small size makes them vulnerable to drowning in water reservoirs, use small test tube setups., slow colony growth can frustrate beginners who overfeed and cause mold., wild-caught colonies may be stressed from their specialized habitat and fail to adapt., overheating from heat sources if not properly regulated.

Temperature and Care

Temnothorax sordidulus needs higher temperatures than many other European Temnothorax. Keep the nest at 22-26 °C, with a slight gradient if possible. In the wild, they nest in rock crevices exposed to direct sunlight, think baking hot ^[5]. A heating cable on one side of the nest can help maintain these temperatures, but place it on top of the nest rather than underneath to avoid overdrying.

Avoid keeping them too damp. These ants come from dry, warm sites. The substrate should be allowed to dry out between waterings. If you use a test tube setup, keep the water reservoir small and check for standing water. Mold is a bigger problem for this species than drying out.

During winter, provide a diapause period of 2-3 months at 5-10 °C. This is essential for their health and likely triggers reproductive cycles. A refrigerator or cold cellar works well for this.

Nesting Preferences

In nature, T. sordidulus nests in rock crevices and dead wood in very hot, dry locations ^[4][5]. They prefer sites with exposed bedrock and sparse vegetation, rocky outcrops baking in the sun. Colonies have been found in gravel deposits, old masonry, and stone walls as secondary habitats ^[8].

For captive care, a Y-tong (AAC) nest with tight chambers works well, or you can use a plaster nest. The key is providing narrow passages scaled to their tiny worker size (about 2-3 mm). A naturalistic setup with flat stones can also work if you maintain the right temperature and humidity balance.

Avoid damp, mold-prone setups. Good ventilation is important while still maintaining warmth. These ants are not arboreal, they are ground‑nesting specialists that tolerate dry conditions far better than most other Temnothorax.

Feeding and Diet

Like other Temnothorax, T. sordidulus is an omnivore that accepts both protein and sugar sources. Feed small insects (fruit flies, small mealworms, pinhead crickets) as protein, and sugar water or honey as carbohydrates. They are small ants, so prey should be appropriately sized.

In the wild, they likely forage for small arthropods and tend aphids for honeydew. Offer food 2-3 times per week for established colonies. Remove uneaten prey after 24-48 hours to prevent mold. Sugar water can be provided constantly via a cotton ball or small container.

Because of their small size, be careful not to overfeed. Excess food decays quickly in small setups and causes the mold problems this species is particularly sensitive to.

Behavior and Temperament

Temnothorax sordidulus is a peaceful species with no aggressive defensive behaviors. Workers are small, slow-moving, and stay out of trouble. They have a modified stinger for smearing venom (smear defense, typical of Crematogastrini) rather than piercing, completely harmless to humans. In the wild, when disturbed, they may freeze and press themselves to the ground ^[9].

This is not a flashy or active species. They prefer to stay in their nests and forage quietly. Colonies remain small, typically under a few hundred workers. The queen is small and inconspicuous.

Their small size means they cannot travel far or tackle large prey. They are best suited to keepers who appreciate subtle ants rather than those wanting dramatic foraging swarms.

Colony Founding

Founding behavior has not been directly studied for this species, but pleometrosis (multiple queens founding together) has been observed in the wild. Only one queen remains functional after the first workers emerge ^[4]. The specific founding strategy (claustral vs. semi‑claustral) is unknown.

If you find a young queen, keep her in a dark test tube with a small water reservoir at room temperature (20-22 °C). Be patient: first workers (nanitics) may take 6-10 weeks to appear, depending on temperature. Because the species is monogyne with high relatedness within colonies ^[6], keep only one queen per colony.

Distribution and Range

Temnothorax sordidulus has a restricted distribution centered on the Dinaric Alps of Austria, Croatia, and Slovenia ^[1]. However, recent records show a wider Balkan distribution, with populations in Bosnia, Bulgaria, Greece, Montenegro, North Macedonia, and Turkey ^[10][11]. The first record in France was in 2013,found at 2250 m altitude in the Vésubie valley, 450 km from the nearest known population in Austria ^[2]. This suggests the species may have been overlooked or is expanding its range.

In Austria, the species is at the northern edge of its distribution and is considered threatened. It has been recorded in Carinthia, Styria, and Lower Austria, typically at warm, rocky sites between 300-800 m altitude ^[12][4].

Conservation Status

Temnothorax sordidulus is considered Near Threatened (NT) in Carinthia ^[13] and Category 2 (Strongly Endangered) in Lower Austria ^[4]. In Styria, it makes up only 1.1% of Temnothorax records ^[12]. The species is specialized to very specific hot, dry microhabitats, making it vulnerable to habitat loss and climate change. It is considered an outpost species in Austria, at the northern edge of its natural distribution ^[14].

If you find this species in the wild, observe rather than collect, they are not common and populations are localized. In captivity, keeping this species successfully can help preserve genetic stock of a species facing challenges in its natural habitat.

Frequently Asked Questions

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References