Crematogaster goeldii

Crematogaster goeldii

Crematogaster goeldii is a small Myrmicinae ant native to South America, found in Brazil, Bolivia, and Argentina. Workers are bicolored with a reddish-brown head and mesosoma contrasting against a distinctive black gaster (abdomen). They belong to the Crematogaster crinosa complex, a group characterized by a deeply invaginated propodeal suture and an elevated, compressed dorsal face of the propodeum. This species requires further taxonomic study as it closely resembles C. stigmatica and C. unciata, and they may represent synonyms or a variable species complex ^[1]. In the wild, these ants are known to visit extrafloral nectaries of plants like Tocoyena formosa in Brazilian cerrado habitats, where they forage for sugar sources in canopy environments.

Quick Summary

• Difficulty: Medium
• Origin & Habitat: Native to the Neotropical region, Brazil, Bolivia, and Argentina. Found in cerrado habitats and forest canopies, often nesting in stem galls on trees like Eremanthus erythropappus ^[2][3].
• Colony Type: Colony structure is unconfirmed for this species. Based on related Crematogaster species, likely single-queen colonies. Colonies in the wild are small, with a median of 23 individuals per gall nesting site ^[2].
• Size & Growth:
  • Queen: Unconfirmed, related species typically 5-7mm
  • Worker: Small, approximately 3-4mm based on genus patterns ^[3]
  • Colony: Small colonies, up to perhaps 100-200 workers based on typical Crematogaster crinosa complex patterns ^[2]
  • Growth: Moderate
  • Development: Estimated 6-8 weeks based on genus-level data for tropical Crematogaster species (Development time is estimated from related species in the crinosa complex. Small colony size suggests relatively slow colony growth compared to faster-growing Myrmicinae.)
• Antkeeping:
  • Temperature: Keep at 24-28°C, these are tropical ants from Brazil and Argentina. A gentle temperature gradient is recommended ^[3].
  • Humidity: Moderate to high humidity (60-80%). Provide a moist nest chamber but ensure ventilation to prevent mold. These ants nest in tree galls in humid forest habitats ^[2].
  • Diapause: No, as a tropical species, they do not require hibernation. Keep them warm year-round.
  • Nesting: Prefers tight, enclosed spaces similar to their natural gall-nesting behavior. Y-tong nests, acrylic nests, or test tube setups work well. Provide narrow chambers scaled to their small size. Avoid overly large, open spaces.
• Behavior: These ants are active foragers that readily climb and explore vertical surfaces. They are known for visiting extrafloral nectaries, indicating strong attraction to sugar sources. Workers are relatively small but agile. They may show moderate aggression when defending their nest. Escape prevention is important due to their small size, use fine mesh barriers. They tend to be arboreal (tree-dwelling) in nature, so they may prefer elevated foraging areas.
• Common Issues: small colony size means colonies are vulnerable to stress and disturbance, escape prevention requires fine mesh barriers due to their tiny size, tropical species requires consistent warmth, cold temperatures can be fatal, small colony size makes them sensitive to overfeeding and mold from uneaten food, taxonomic uncertainty means exact care requirements may vary

Housing and Nest Setup

Crematogaster goeldii is a small ant that naturally nests in tree galls and similar enclosed spaces. For captivity, Y-tong (AAC) nests or acrylic nests with narrow chambers work well. Test tube setups can also work for founding colonies. The key is providing appropriately scaled chambers, these ants are tiny, so passages should be narrow. Because they are arboreal (tree-dwelling) in nature, they may appreciate some vertical space for foraging. Ensure escape prevention is excellent, their small size means they can squeeze through gaps that larger ants cannot. Use fine mesh on any openings and check connections regularly. A small outworld area with vertical surfaces (like cork or twigs) will mimic their natural canopy-foraging behavior. ^[2][3]

Feeding and Diet

In the wild, these ants are known to visit extrafloral nectaries, showing a strong attraction to sugar sources. In captivity, offer sugar water, honey, or diluted honey water as a constant energy source. For protein, provide small insects like fruit flies, pinhead crickets, or small mealworms. Given their small colony sizes in the wild (median 23 individuals per gall), be careful not to overfeed, remove uneaten prey within 24-48 hours to prevent mold. Feed protein 1-2 times per week, and keep sugar water available at all times. Their small size means even tiny prey items are appropriate. ^[2]

Temperature and Humidity

As a tropical species from Brazil and Argentina, Crematogaster goeldii requires warm temperatures. Keep the nest area at 24-28°C. A heating cable on one side of the nest can create a gentle gradient if your room temperature is below this range. Place the heating on top of the nest, not underneath, to avoid evaporating moisture too quickly. For humidity, aim for 60-80%, these ants naturally inhabit humid forest environments and tree hollows. Keep the nest substrate consistently moist but not waterlogged. Provide a water tube or moisture chamber, and check that condensation is present but not excessive. Good ventilation is important to prevent mold while maintaining humidity. ^[3]

Colony Dynamics and Growth

Wild colonies of C. goeldii are relatively small, with a median of only 23 individuals per gall including workers, brood, and eggs ^[2]. This suggests colonies in captivity will also remain modest in size, likely reaching 100-200 workers at maturity rather than the thousands seen in some Myrmicinae. The small colony size means growth will feel slow compared to species like Lasius or Camponotus. Be patient, founding colonies may take many months to reach 20-30 workers. Avoid the temptation to overfeed or disturb the colony frequently. Small colonies are more vulnerable to stress, so minimize disturbances during the founding stage.

Behavior and Temperament

Crematogaster ants have a distinctive behavior, when threatened, they raise their gaster (abdomen) in a defensive posture, ready to spray formic acid or sticky substances at intruders. This is their primary defense mechanism. They are active foragers and will readily explore their outworld, including climbing vertical surfaces. Their small size makes them quick and agile. They are not particularly aggressive toward humans but will defend their nest vigorously. When keeping them, watch for escape attempts, their tiny size means they can slip through surprisingly small gaps. Regular colony checks and fine mesh barriers are essential. ^[3]

Frequently Asked Questions

References