Formica puberula

Quick Summary

• Difficulty: Medium
• Origin & Habitat: Western North America, including the United States and southern Canada. Found in sagebrush scrub, grasslands, mixed forests, ponderosa pine and aspen forests, and urban habitats ^[1]. In Nevada, they occur at 4,500-8,200 ft elevation in coniferous forest biomes and mountain meadows ^[3].
• Colony Type: Facultative slavemaker, queen number unconfirmed ^[1]. Colonies typically enslave workers from Formica neogagates, fusca, and pallidefulva species groups ^[1].
• Size & Growth:
  • Queen: Size data unavailable for queens, inferred from Formica genus as ~8-10 mm ^[1].
  • Worker: 5-7 mm ^[1].
  • Colony: Up to several thousand workers at maturity ^[1].
  • Growth: Moderate
  • Development: Estimated 6-8 weeks at optimal temperature ^[1]. (Development time inferred from related Formica species, direct measurements not available for this species.)
• Antkeeping:
  • Temperature: Keep at room temperature (20-24°C) with a slight gradient ^[1].
  • Humidity: Provide a humidity gradient, keep nest substrate consistently moist but not waterlogged, mimicking under-stone conditions ^[1].
  • Diapause: Yes, based on genus patterns and geographic range, provide 3-4 months of winter dormancy at 5-10°C.
  • Nesting: Y-tong (AAC) or plaster nests work well, provide test tube setup for founding colonies, then move to formicarium once established ^[1].
• Behavior: Workers spray formic acid for defense, as they lack a functional sting. They are moderately aggressive during raids but generally calm in captivity. Escape risk is moderate due to their size, use standard Formica escape prevention ^[1].
• Common Issues: slave-raiding behavior can cause stress to nearby ant colonies if housed together, keep them isolated, winter dormancy is essential, skipping hibernation will weaken or kill the colony over time, laboulbenia formicarum fungus can infect workers, reducing lifespan ^[5], founding queens may fail to establish if they cannot find a suitable host colony

Nest Preferences and Housing

In the wild, Formica puberula nests under stones, logs, or builds small soil mounds at the base of trees like aspen. They prefer shaded locations in coniferous forests and mountain meadows at higher elevations ^[1]. For captive care, a Y-tong (AAC) nest or plaster formicarium works well, these mimic the damp, stable conditions under stones. Founding colonies can be started in a test tube setup, but established colonies need more space. Provide a water tube for humidity but avoid flooding the nest chambers. They do best with a moderate humidity level and some ventilation to prevent mold ^[1].

Feeding and Diet

Formica puberula is omnivorous with a preference for protein and sugar. They tend aphids for honeydew in the wild and are mutualistic with several aphid species including Aphis salicariae, Aphis varians, and Rhopalosiphum nymphaeae ^[4]. In captivity, offer sugar water or honey as a constant energy source, and protein sources like mealworms, crickets, or other insects 2-3 times per week. They will also scavenge on dead insects. Because they are slavemakers, you can optionally provide them with Formica host species workers if the colony is established enough to support enslaved workers ^[1].

Temperature and Seasonal Care

Keep Formica puberula at room temperature (20-24°C) with a slight thermal gradient so workers can choose their preferred zone. They naturally occur in temperate regions and higher elevations, so they can tolerate cooler temperatures than tropical species. More importantly, they require a proper winter dormancy period, plan for 3-4 months of hibernation at 5-10°C during winter months. In their native range, they experience cold winters at elevations above 4,500 feet. Skipping hibernation will weaken the colony and can lead to death over time. Initial spring activity has been observed starting around April ^[3].

Slave-Making Behavior

Formica puberula is a facultative slavemaker in the Formica sanguinea group. This means they can survive without slaves but typically have them. Queens use parasitic founding, they invade small colonies of other Formica species (typically from the neogagates, fusca, and pallidefulva species groups), somehow eliminate the host queen, and get the host workers to accept them. The workers that emerge from the captured brood become enslaved and work for the slavemaker colony. Once established, raiding parties go out to capture more slaves from nearby Formica colonies ^[2][1]. In captivity, this behavior is mostly of academic interest, you don't need to provide host species unless you want to observe the raiding behavior, and doing so adds complexity.

Health and Common Problems

One specific health concern for Formica puberula is infection by the fungus Laboulbenia formicarum. This parasite attaches to workers and can be quite abundant on infested individuals. Infested workers continue foraging seemingly unaffected, but the infection likely reduces overall lifespan ^[5]. Other common issues include: colony stress from improper hibernation, escape attempts (moderate risk for this size), and difficulty with founding queens who may fail to establish if they can't find a suitable host colony. Always use proper escape prevention and maintain appropriate seasonal temperature cycles.

Frequently Asked Questions

Report an Issue

The current care sheet is based fully on literature. See inconsistencies, or something that's incorrect? Please report here, it will be resolved after review from an admin. Contributing to the blogs tab also helps providing information, to make us be able to further improve the caresheets. Thank you for your support!

References