Temnothorax racovitzai

Quick Summary

• Difficulty: Easy
• Origin & Habitat: Western Mediterranean, Portugal, Spain, France (including Corsica), Italy, Croatia, Montenegro, Serbia, the Balearic Islands and Gibraltar. Found in warm, forested habitats such as holm oak forest, secondary pine forest, shrublands and riparian areas, at elevations from 10 to 1250 m ^[2][4][1].
• Colony Type: Based on genus patterns, likely monogyne (single‑queen). Colony structure has not been studied in detail, but *Temnothorax* generally form small, monogynous colonies.
• Size & Growth:
  • Queen: Size data unavailable, inferred from *Temnothorax* genus, approximately 3-4 mm.
  • Worker: 2.2 mm ^[1]
  • Colony: Size data unavailable, based on typical *Temnothorax* litter‑ant colonies, probably up to a few hundred workers.
  • Growth: Moderate
  • Development: Unknown, not documented for this species. Inferred from related *Temnothorax*: roughly 6-10 weeks at 22-24°C, but this is speculative. (Development time likely depends on temperature and food availability. No published data for *T. racovitzai*.)
• Antkeeping:
  • Temperature: Keep at room temperature, ideally 20-24°C. The species occurs in areas with mean summer air temperatures around 19°C, so no extra heating is needed in most homes ^[2]. Avoid prolonged temperatures below 15°C or above 28°C. A very mild heat cable on one side of the nest can create a gradient but is rarely required.
  • Humidity: Provide a moisture gradient in the nest. Keep at least one area of the substrate consistently damp but not waterlogged, think of a well‑wrung sponge. In the wild they inhabit relatively humid understorey areas (holm oak forests, riparian zones) but also sunny, dry spots, so a range of moisture is ideal ^[8][5].
  • Diapause: Yes, likely needed. Their temperate Mediterranean distribution (with cool winters) indicates a winter rest period. A 2-3 month cool phase at 10-15°C is recommended (e.g. in an unheated cellar or fridge). Avoid dropping below 5°C ^[2].
  • Nesting: Small, tight chambers suit these tiny ants. Y‑tong (AAC) nests, plaster nests, soil nests or 3D‑printed nests with narrow passages work well. They naturally nest under loose pine bark, in fallen twig fragments on the ground, and under stones ^[9][1]. A test tube setup is perfect during founding and early colony growth.
• Behavior: Peaceful and cryptic, workers flee rather than fight. Belonging to the subfamily Myrmicinae (tribe Crematogastrini), they possess a modified flattened stinger used to smear venom onto enemies rather than sting, this poses no danger to keepers. They are most active in the evening ^[10] and tend to stay hidden. Escape risk is high because of their tiny size, fine mesh or fluon barriers are essential.
• Common Issues: tiny size makes escape easy, use very fine mesh or PTFE barriers and seal all gaps, slow growth can tempt keepers to overfeed or disturb the colony, which stresses the queen, wild‑caught colonies may carry the fungus *Myrmicinosporidium durum*, visible through the body wall as dark spots, infected workers often die after hibernation ^[7], they are vulnerable to displacement by the invasive Argentine ant (Linepithema humile) ^[11] so never release them in non‑native areas, colony health can decline if moisture is not balanced, too dry kills brood, too wet promotes mould

Housing and Nest Setup

Because Temnothorax racovitzai is so tiny, everything in the nest must be scaled down. A Y‑tong (AAC) nest with chambers no more than about 5 mm high works well, as does a small plaster or soil nest with narrow passages. In nature they are found under loose bark of pine trees, in small fallen twig fragments, and under stones in scree ^[9][1]. Mimic this by offering tightly packed spaces, avoid large open chambers. For founding, a test tube with a water reservoir (cotton plug) is perfect, keep it horizontal and dark. Once the colony has 15-20 workers, you can connect a small outworld and eventually a nest formicarium. Escape prevention is critical, use very fine stainless steel mesh (0.2 mm) or a fluon barrier around the outworld.

Temperature and Seasonal Care

Keep the colony at normal room temperature,20-24°C. T. racovitzai lives in places where average summer air temperatures are about 19°C, so you do not need extra heating unless your home is unusually cool ^[2]. Avoid temperatures below 15°C for long periods during the active season and never exceed 28°C. A winter diapause is recommended: 2-3 months at 10-15°C (e.g. in an unheated room). The species experiences cool winters in its native range, and skipping diapause may weaken the colony. Do not let temperatures drop below 5°C during diapause. If your colony is very small (under 10 workers) or has been stressed, you can skip the first winter rest.

Feeding and Diet

These ants are omnivorous but mostly eat sweet liquids and small prey. Provide a constant source of sugar water (1:3 sugar to water) or diluted honey. For protein, offer tiny insects: fruit flies, small pinhead crickets, small mealworms, or pieces of fresh shrimp. In the wild they forage for honeydew from aphids and scavenge small invertebrates ^[9]. Feed two or three times a week in small amounts, remove any leftover prey after 24 hours to prevent mold. They also need a constant supply of clean water (e.g. a small test‑tube waterer in the outworld).

Humidity and Water

T. racovitzai occurs in habitats that range from moist holm‑oak understorey to dry, sunny pine forests ^[8][5]. In captivity, provide a moisture gradient: keep part of the nest substrate damp (like a wrung‑out sponge) and let the rest dry out. A water tube connected to the nest will supply a constant humid zone. Do not keep the entire nest saturated, this can cause mold. If using a plaster nest, wet the plaster a little every 3-5 days. Watch the ants: they will cluster in the area with the moisture level they prefer.

Colony Development

No published data exist on development times for T. racovitzai. Based on related Temnothorax, egg‑to‑worker probably takes about 6-10 weeks at 22-24°C. The founding queen is not confirmed to be claustral, please assume founding behaviour is unconfirmed. After the first workers emerge, growth is moderate, the colony may reach 30-50 workers in the first year under good conditions. Maximum colony size is unknown but likely under a few hundred workers. Be patient and avoid disturbing the nest too often.

Health Concerns

A known threat is the parasitic fungus Myrmicinosporidium durum, reported from Spanish populations of T. racovitzai ^[7]. Its spores are visible through the ant's cuticle as dark spots. Infected workers appear to behave normally but often die after hibernation. The fungus can also infect queens and males ^[7]. If you suspect infection, isolate the colony and keep the nest drier than usual (the fungus thrives in damp conditions). The Argentine ant (Linepithema humile) displaces T. racovitzai in invaded areas ^[11], keep your ants secure and never release them into nature.

Behavior and Temperament

T. racovitzai is a shy, cryptic ant. Workers flee rather than attack. Like other members of Crematogastrini, they use a smear defense, a modified stinger that wipes venom onto enemies instead of piercing. This is harmless to humans. They are most active in the evening, nuptial flights are thought to occur then ^[10]. In the nest, they prefer the darker, moister chambers. These ants are not showy, they are best suited to keepers who enjoy careful observation of a small, quiet colony.

Frequently Asked Questions

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References