Temnothorax silvestrii

Quick Summary

• Difficulty: Medium
• Origin & Habitat: Southern Arizona (United States) and northern Mexico (Sonora, Baja California Sur). Nests in larger limbs of evergreen oaks, particularly Quercus emory, in oak forests at elevations of 3,500 ft or more ^[1][2][3][4].
• Colony Type: Single-queen colonies (monogyne) with up to 70 workers ^[4].
• Size & Growth:
  • Queen: Exact size not reported in literature, queens are slightly larger than workers (~3.2-3.4mm) based on congeneric species.
  • Worker: 3.2-3.4mm ^[4]
  • Colony: Up to 70 workers ^[4]
  • Growth: Moderate
  • Development: Likely 6-10 weeks under optimal conditions (inferred from related Temnothorax species) (Development time not directly studied for this species.)
• Antkeeping:
  • Temperature: Based on its oak forest habitat in Arizona and Mexico, maintain 22-26°C. Provide a temperature gradient so workers can self-regulate. Avoid extreme heat or cold ^[1].
  • Humidity: Keep the nest substrate slightly moist but not waterlogged. Good ventilation is essential to prevent mold. Natural habitat: oak forests with moderate moisture levels.
  • Diapause: Likely yes. Temperate origin suggests a winter dormancy period is beneficial. Cool to 10-15°C for 2-3 months (November-February) and keep nest slightly damp. Skip feeding during this period.
  • Nesting: Arboreal nester that prefers tight, enclosed spaces. In captivity, Y-tong (AAC) or plaster nests with narrow chambers work well. Provide small twigs or wood pieces for enrichment. Avoid large, open formicaria ^[4].
• Behavior: Generally peaceful and non-aggressive. Workers are active diurnal foragers that may use tandem-running recruitment. When threatened, they may employ a venom-smearing defense typical of Crematogastrini (without citation). Escape risk is moderate due to their small size, use fine mesh and tight lids. They are shy and may flee rather than fight.
• Common Issues: slow colony growth due to naturally small colony size, requires patience, escape risk, use fine mesh on all openings as workers can squeeze through tiny gaps, overfeeding protein can cause mold, offer small amounts and remove leftovers, winter dormancy may be needed, skipping hibernation could weaken colonies over time, colonies may fail if nest is too wet or poorly ventilated, maintain moderate humidity

Housing and Nest Setup

Temnothorax silvestrii is an arboreal species that naturally nests in larger limbs of evergreen oaks, especially Quercus emory ^[1][4]. In captivity, Y-tong (AAC) nests or plaster nests with narrow, tight chambers work well because they mimic the enclosed spaces these ants prefer. Avoid large, open formicaria. A small outworld (e.g.,20x15 cm) is enough for a colony of this size. Use fine mesh on all ventilation holes, workers are small but not tiny enough to pass through standard ant mesh if properly installed. Provide small twigs or bark pieces as enrichment. Since colonies stay under 100 workers, a small nest chamber is sufficient.

Feeding and Diet

Like most Temnothorax, T. silvestrii is omnivorous. In nature they likely tend aphids for honeydew and scavenge small insects. In captivity, offer a constant supply of sugar water or honey water. For protein, give small prey such as fruit flies, pinhead crickets, or tiny mealworm pieces. Feed protein 2-3 times per week, remove any uneaten prey after 24 hours to prevent mold. Their appetites are modest, a single fruit fly may feed several workers. Avoid overfeeding, which can attract mites or cause mold growth. ^[4]

Temperature and Seasonal Care

Maintain 22-26°C during the active season. This species comes from Arizona and northern Mexico at elevations above 3,500 ft, so it experiences warm summers and cooler winters ^[1]. A heating cable on one side of the nest creates a useful gradient. During winter (November-February), reduce temperature to 10-15°C for a dormancy period. This hibernation mimics their natural cycle. Keep the nest substrate slightly moist during this time but do not offer food. A cool basement or garage works well. Skipping hibernation may weaken the colony over time.

Colony Development

Colony founding has not been reported in the literature. Based on typical Temnothorax biology, the queen likely raises the first workers without outside help (claustral founding), but this is not confirmed. Once the first nanitic workers emerge, they take over foraging and brood care. Growth is slow, expect several months to reach 20-30 workers, and a mature colony of up to 70 workers may take a year or more. Do not rush: small colony size is natural for this species. Patience and minimal disturbance are key. ^[4]

Behavior and Observation

Workers are diurnal, active foragers. They may use tandem-running to recruit nestmates to food, a behavior seen in many Temnothorax species. Their defense mechanism is typical of Crematogastrini: they smear venom rather than sting deeply, but they are non-aggressive and prefer to flee. Use a red film or dark cloth over the nest if you want to observe without disturbing them. Their small size makes them fascinating to watch, but they will retreat into the nest if startled. ^[4]

Frequently Asked Questions

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References