Temnothorax carinatus

Temnothorax carinatus

Temnothorax carinatus is a small, yellow-brown ant species native to the southwestern United States and northern Mexico. Workers measure around 2.8mm in total body length, while queens are larger at approximately 4.5mm. This species is easily identified by its 12-segmented antennae, the postpetiole being 1.5-1.65 times wider than the petiole, and small propodeal angles rather than well-developed spines. The body is mostly smooth and shining with fine striolae on the head. They belong to the tricarinatus-group and the sallei-clade within the genus Temnothorax ^[1][2].

These ants inhabit a remarkable range of environments, from desert grasslands and juniper forests with cholla cacti to desert riparian sites and pine forests at higher elevations. They are most commonly found nesting beneath stones, with colonies typically containing 29-182 workers. The species is monogyne, meaning each colony has a single queen. They are known to be common in the Chisos Mountains of Texas ^[3].

Quick Summary

• Difficulty: Easy
• Origin & Habitat: Southwestern United States (Wyoming, Nevada, New Mexico, Arizona, western Texas) and northern Mexico (Chihuahua). Found in desert grasslands, juniper forests with cholla, desert riparian sites, up to pine forests at various elevations ^[3].
• Colony Type: Monogyne, single queen colonies with 29-182 workers ^[3].
  • Colony: Monogyne
  • Founding: Claustral
• Size & Growth:
  • Queen: 4.5mm total length ^[3]
  • Worker: 2.82mm total length ^[3]
  • Colony: Up to 182 workers ^[3]
  • Growth: Moderate
  • Development: 6-10 weeks (Estimated based on typical Temnothorax development patterns. Related species in this genus typically develop from egg to worker in 6-10 weeks at optimal temperatures.)
• Antkeeping:
  • Temperature: Keep at room temperature, roughly 20-24°C. This species tolerates a range from cooler desert nights to warmer daytime conditions, so a moderate temperature gradient works well.
  • Humidity: Moderate humidity. These ants naturally nest under stones in areas that can experience both arid and semi-arid conditions. Keep the nest substrate slightly moist but allow it to dry partially between waterings.
  • Diapause: Yes, this species is found in regions with cold winters (Wyoming, high elevations in Arizona/Texas). A winter rest period at 10-15°C for 2-3 months is recommended.
  • Nesting: Naturally nests under stones in the wild. In captivity, a Y-tong (AAC) nest, plaster nest, or test tube setup works well. They prefer tight-fitting chambers scaled to their small size. Avoid tall, open spaces.
• Behavior: Generally peaceful and non-aggressive. Workers are small but active foragers. They are not known to sting significantly. Escape prevention is important due to their tiny size, use fine mesh barriers and tight-fitting lids. They use tandem-running recruitment to guide nestmates to food sources, a common behavior in this genus.
• Common Issues: escape prevention is critical due to their very small size, they can squeeze through tiny gaps, colonies are relatively small (under 200 workers) so growth appears slow, test tube setups can dry out quickly, monitor moisture levels regularly, wild-caught colonies may have parasites that can cause colony failure

Nest Preferences

In the wild, Temnothorax carinatus nests beneath stones in a variety of habitats from desert grasslands to juniper forests and pine forests. The colonies are relatively small, typically containing fewer than 200 workers. For captive care, a Y-tong (AAC) nest or plaster nest works well because these materials hold moisture without becoming waterlogged. Test tube setups are also suitable, especially for founding colonies. The key is providing tight chambers scaled to their tiny body size, these ants do not need large, open spaces. A naturalistic setup with flat stones on top of soil can also work, mimicking their natural under-stone nesting behavior. Keep the nest in a quiet area with minimal vibration, as Temnothorax species can be sensitive to disturbances. ^[3]

Feeding and Diet

Temnothorax carinatus is a generalist feeder typical of the genus. Workers forage for honeydew, small insects, and other protein sources. In captivity, offer a mix of sugar water or honey as a constant energy source, and protein-rich foods like small crickets, mealworms, fruit flies, or other tiny insects twice weekly. They are small ants, so prey items should be appropriately sized, wingless fruit flies and small springtails are ideal. Remove any uneaten prey after 24-48 hours to prevent mold. A varied diet helps ensure healthy colony development. Some colonies may readily accept sugar water, while others prefer honeydew substitutes, offering both helps you learn your colony's preferences. ^[3]

Temperature and Seasonal Care

This species tolerates a wide temperature range reflecting its diverse habitats from desert grasslands to pine forests. Room temperature (20-24°C) is ideal for keeping the colony active and developing brood. A heating cable on one side of the nest can create a gentle gradient if your room runs cool, but is not strictly necessary. For winter care, this species requires a diapause period due to its range extending into regions with cold winters (Wyoming, high elevations). Reduce temperature to 10-15°C for 2-3 months during winter, typically from late autumn through early spring. During diapause, reduce food offerings but do not let the nest dry out completely. Resume normal temperatures and feeding gradually in spring to trigger renewed activity and reproduction. ^[3]

Behavior and Colony Dynamics

Temnothorax carinatus is a peaceful species with no significant defensive sting. Workers are active foragers that use tandem-running recruitment, where one worker leads another directly to food sources, this is a notable behavior in the genus. Colonies are monogyne with a single queen, and worker numbers remain modest at under 200 individuals even in mature colonies. The queen is claustral, meaning she seals herself in a chamber during founding and raises her first workers entirely on stored body fat without foraging. First workers (nanitics) are smaller than mature workers but quickly begin foraging to support colony growth. The small colony size and peaceful nature makes them suitable for observation in formicariums where you can watch their social interactions. ^[3]

Frequently Asked Questions

References