Temnothorax interruptus

Temnothorax interruptus - "Long-spined Ant"

Temnothorax interruptus is a small, colorful ant measuring 2.3-3.4mm for workers. Workers are light yellow to orange with a distinctive dark brown to black transverse band across the first gastral segment, often interrupted in the middle. The head typically shows darker markings at the front corners, and the antennal club is distinctly dark. These ants have long, curved propodeal spines and a steeply peaked petiole node in profile. This Turano-European species ranges from Spain to the Caucasus, inhabiting xerothermic grasslands and open dry habitats with warm, sunny conditions ^[1].

These ants are ground-nesting specialists that prefer dry, warm habitats with low vegetation cover. Colonies are relatively small, typically containing 50-100 workers in established nests, though they can reach a few hundred workers. They are known hosts for the social parasite Temnothorax ravouxi ^[2]. The species is semi-claustral, meaning queens must leave the nest to forage for food during the founding stage, unlike fully claustral species that rely entirely on stored fat reserves ^[3][4].

Quick Summary

• Difficulty: Medium
• Origin & Habitat: Turano-European species found across Central and Southern Europe, from Spain to the Caucasus. Prefers xerothermic grasslands, dry meadows, limestone and gypsum rocky areas, and edges of dry deciduous oak forests. Requires warm, sunny, open habitats with low vegetation cover ^[1][5].
• Colony Type: Facultatively polygynous, colonies can be monogynous (single queen) with one macrogyne or polygynous with several microgynes (tiny replacement queens). Worker numbers reach a few hundred ^[6][7].
  • Colony: Optionally polygyne
  • Founding: Semi-claustral
• Size & Growth:
  • Queen: 3.6-3.7mm for normal queens (macrogynes),3mm for tiny queens (microgynes) ^[8]
  • Worker: 2.3-3.4mm
  • Colony: 50-100 workers in typical British colonies, up to a few hundred in larger colonies ^[9][6]
  • Growth: Slow, semi-claustral species have slower larval development and queens must forage during founding ^[3]
  • Development: 6-10 weeks estimated based on related species and Strategy F classification ^[3][4] (Semi-claustral founding means slower initial growth, queens must leave to hunt for food rather than living solely on stored reserves. Larval diapause occurs, with first egg-laying after diapause ^[3][4].)
• Antkeeping:
  • Temperature: Warm conditions required, this is a xerothermophilous species. Keep nest area at 24-28°C with a gentle gradient. Avoid temperatures below 20°C as they prefer warm, sunny habitats ^[5][10].
  • Humidity: Low to moderate, prefers dry conditions. Keep substrate moderately dry, similar to their natural grassland habitat. Provide a small water tube but avoid damp conditions ^[5].
  • Diapause: Yes, requires winter diapause period. Keep at 5-10°C for 2-3 months during winter months (roughly November-February in the Northern Hemisphere). This species experiences larval diapause in the wild ^[3].
  • Nesting: Ground-nesting species that naturally nests in soil, under stones, in moss, or in rock crevices. In captivity, a naturalistic setup with a digging area or a Y-tong/plaster nest works well. Provide small stones or rubble as they would use in the wild ^[1][5].
• Behavior: Generally peaceful and non-aggressive. Workers are active foragers that hunt small prey like springtails. They are not stingers but can bite if threatened. These are small ants with moderate escape risk, use standard barriers. They are known to compete with Temnothorax unifasciatus in overlapping habitats ^[11].
• Common Issues: slow growth during founding stage, semi-claustral queens must forage, leading to higher founding failure rates, escape prevention needed, small size means they can squeeze through small gaps, damp conditions are harmful, these xerophilous ants easily develop mold problems in humid setups, colonies remain small, maxing out around 100-300 workers, so expectations must be realistic, winter diapause is essential, skipping hibernation will weaken or kill colonies

Housing and Nest Setup

Temnothorax interruptus is a ground-nesting species that naturally nests in soil, under stones, in moss, or in rock crevices in warm, dry habitats ^[1][5]. For captivity, a naturalistic setup with a digging area filled with sandy soil works well. You can also use a Y-tong (AAC) nest or plaster nest, but provide some dry areas as they prefer not-too-humid conditions. These ants are small, so use tight-fitting connections and fine mesh for escape prevention. A small water tube should be provided, but do not over-moisten the substrate, these are xerophilous ants that easily develop mold problems in damp conditions. Adding small stones or pieces of bark to the outworld mimics their natural rock-rubble nesting sites.

Feeding and Diet

Workers are active predators that hunt smaller insects, particularly springtails ^[5]. In captivity, offer small live prey like fruit flies, pinhead crickets, and most importantly, springtails. They will also accept other small arthropods. Sugar sources are sometimes accepted, you can offer a drop of diluted honey or sugar water occasionally, but protein-rich live prey should be the primary food. Feed small amounts 2-3 times per week, removing any uneaten prey after 24 hours. The semi-claustral founding mode means queens must hunt during colony establishment, so ensure food is available even during early founding stages.

Temperature and Seasonal Care

This is a xerothermophilous species requiring warm conditions. Keep the nest area at 24-28°C during the active season, with a gentle gradient allowing workers to choose their preferred temperature. Avoid temperatures below 20°C, they thrive in warm, sunny habitats in the wild. During winter, a diapause period is essential. Keep colonies at 5-10°C for 2-3 months, typically from late autumn through winter (roughly November to February in the Northern Hemisphere). The species experiences larval diapause in the wild, with first egg-laying occurring after diapause ^[3][4]. Do not skip hibernation, this will weaken or kill colonies.

Colony Development and Growth

Temnothorax interruptus is a semi-claustral species, which means colony growth is slower than fully claustral species like Lasius or Camponotus. Queens must leave the nest to forage for food during the founding stage, making this phase riskier and slower ^[3][4]. Expect 6-10 weeks from egg to first worker at optimal temperatures, though this may take longer if temperatures are suboptimal. Colonies remain relatively small, typically 50-100 workers in natural British colonies, up to a few hundred in optimal conditions ^[9][6]. Growth is independent, meaning the queen raises the first workers alone without the benefit of stored fat reserves. Be patient during founding and do not disturb the queen unnecessarily.

Behavior and Temperament

These ants are generally peaceful and not aggressive toward humans. Workers are active foragers that patrol the outworld searching for small prey. They are not equipped with functional stingers, being in the subfamily Myrmicinae, they can bite but the pain level is minimal. They are known to compete with Temnothorax unifasciatus in overlapping habitats ^[11]. As hosts for the social parasite Temnothorax ravouxi, they may encounter parasitic ants in the wild, but this does not affect captive care. Workers are small but active, and standard escape prevention measures should be sufficient. They are diurnal and most active during daylight hours in warm conditions.

Frequently Asked Questions

References