Solenopsis metallica

Quick Summary

• Difficulty: Medium
• Origin & Habitat: Native to southeastern Atlantic Forest region of Brazil (Santa Catarina, Paraná, Rio de Janeiro) and Misiones Province, Argentina. Found in subtropical humid forest at elevations around 1200 m in the highlands of Santa Catarina, often under closed canopy ^[1].
• Colony Type: Unknown, no specific data on social structure for this species. Related Solenopsis saevissima group species are typically monogyne (single queen), but polygyny occurs in some. Based on the group, likely monogyne, but not confirmed.
• Size & Growth:
  • Queen: 6.1-6.4 mm ^[1]
  • Worker: Worker body length not directly reported in literature, based on related Solenopsis saevissima group species, major workers likely reach 4-6 mm total length (inferred).
  • Colony: Unknown for this species. Related fire ants in the saevissima group can form colonies of up to 20,000+ workers at maturity.
  • Growth: Moderate, fire ants grow quickly after the founding phase, but early growth is slow.
  • Development: Unknown, no specific data for this species. Based on related fire ants, development may take 5-7 weeks at optimal temperatures (24-28°C). (Development is temperature-dependent, warmer conditions speed up brood development.)
• Antkeeping:
  • Temperature: Aim for warm, stable conditions around 24-28°C, based on its subtropical humid forest habitat ^[1]. Use a heating cable on one side of the nest to create a gradient. Avoid prolonged temperatures below 20°C or above 32°C.
  • Humidity: High humidity is essential, these ants live under closed canopy in subtropical forests. Keep the nest substrate consistently moist but not waterlogged. The substrate should feel damp to the touch. Provide a water source (e.g., test tube) for drinking.
  • Diapause: Not required given subtropical origin. Maintain stable temperatures year-round. If colony activity drops in winter, a mild cool period (15-18°C for 2-3 months) is optional but not necessary.
  • Nesting: Use a nest that retains humidity well, such as Y-tong (AAC), plaster, or 3D-printed nests. Fire ants prefer dark, enclosed spaces with multiple chambers connected by narrow passages. Provide deep substrate chambers (at least 5-10 cm) for expansion. Never use acrylic nests, they dry out too quickly and are prone to condensation.
• Behavior: Significantly less aggressive than Solenopsis invicta, they are less likely to attack when the nest is disturbed and have a less painful sting ^[1]. Workers are active foragers that search food systematically. They can sting, but it’s mild. Escape prevention is critical due to their small size, use fluon barriers and fine mesh (≤0.5 mm) on ventilation openings.
• Common Issues: escape prevention, small workers can slip through tiny gaps, use fine mesh and barrier tape on all openings., humidity management, too dry stops growth, too wet leads to mold, keep substrate damp but not soaked., overheating, keep nest below 32°C, avoid direct sunlight., aggression, while less aggressive than other fire ants, they will still sting when threatened, handle with care., founding queen failure, conditions must be stable during founding, disturbances can cause queen abandonment or death.

Housing and Nest Setup

Solenopsis metallica does well in Y-tong (AAC) or plaster formicariums that hold humidity well. Fire ants prefer dark, enclosed spaces, so cover three sides of the nest with dark material to reduce stress. The nest should have multiple chambers connected by narrow passages, fire ants like to organize brood across different chambers. Provide a water test tube as a moisture source and for drinking. For the outworld, use a simple foraging area with a fluon barrier to prevent escapes. Given their small size, inspect all connections and lid edges carefully for gaps ^[1].

Feeding and Diet

Like other fire ants, S. metallica is omnivorous. Offer protein foods like small insects (fruit flies, small crickets, mealworms) and sugar sources like honey water or sugar water regularly. In the wild, they forage for insects and tend honeydew-producing aphids. Feed small amounts of protein 2-3 times per week, removing uneaten prey after 24 hours. Keep sugar water or honey available constantly. Fire ants are aggressive foragers, so place food in the outworld where workers can easily access it ^[1].

Temperature and Seasonal Care

Maintain nest temperatures between 24-28°C for optimal colony health. This species comes from subtropical humid forests, so warmth is important. Use a heating cable on one side of the nest to create a temperature gradient, but never place heating directly on the nest as it can cause drying and overheating. Room temperature around 24°C is often suitable. Diapause is not required, but if your colony shows reduced activity during winter, you can provide a mild cool period at 15-18°C for 2-3 months. Monitor colony behavior, active foragers indicate good conditions, while ants clustering near moisture suggest overheating or dryness ^[1].

Behavior and Temperament

One of the most notable traits of S. metallica is its significantly less aggressive temperament compared to Solenopsis invicta and other fire ants. When the nest is disturbed, they show a much milder response and are less likely to sting ^[1]. Workers are active foragers that search for food systematically across the outworld. They can sting, but the sting is reportedly less painful than the notorious fire ant sting. Despite their calmer temperament, they will still defend their colony vigorously if threatened. Escape prevention is important due to their small size, they readily climb smooth surfaces and can squeeze through remarkably small gaps. Use fluon barrier tape on all container rims and ensure ventilation holes are covered with fine mesh ^[1].

Colony Founding

Founding behavior is unconfirmed for this species. Based on related Solenopsis saevissima group species, queens are likely claustral founders, sealing themselves in a small chamber and relying on stored fat reserves to produce the first brood. If this is the case, keep the queen in a dark, quiet location with stable temperature around 26°C and high humidity during founding. Disturbances can cause queen abandonment or death. Expect first workers to emerge after roughly 5-7 weeks if conditions are optimal ^[1].

Growth and Development

Colony growth follows the typical fire ant pattern: slow initially during the founding phase, then accelerating once the first workers emerge. The first generation of workers (nanitics) are smaller than mature workers but help the colony begin foraging for additional food. As the colony grows, the queen's egg output increases, leading to exponential growth. A mature colony can contain thousands of workers organized into task groups. Development from egg to worker takes approximately 5-7 weeks at optimal temperature, with warmer temperatures potentially speeding this process. Be patient during the first few months ^[1].

Frequently Asked Questions

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References