Crematogaster jardinero

Quick Summary

• Difficulty: Expert
• Origin & Habitat: Neotropical region, Costa Rica and Ecuador. Found in primary wet forest on the Atlantic slope at elevations around 500m, specifically documented in Braulio Carrillo National Park and surrounding areas ^[1].
• Colony Type: Monogyne, single queen colonies. Research found only one physogastric queen across ten dissected ant gardens, suggesting strict monogyny. Workers, brood, males, and alate queens are dispersed evenly throughout the garden matrix rather than concentrated in one area ^[1].
• Size & Growth:
  • Queen: Small queen, described as small shiny queen with posteriorly produced propodeum ^[1]. Size data unavailable.
  • Worker: ~3-4mm, inferred from Crematogaster genus patterns ^[1].
  • Colony: Colony size is not well documented. Ant gardens can be extensive with one central garden described as the largest in an archipelago spanning multiple tree crowns ^[1].
  • Growth: Unknown
  • Development: Unknown, development has not been studied in this species. (Development timeline is unconfirmed.)
• Antkeeping:
  • Temperature: Keep at 22-26°C, they come from tropical wet forest at 500m elevation in Costa Rica where temperatures are warm year-round. Avoid temperatures below 18°C.
  • Humidity: High humidity required, these ants live in rainforest canopy environments where humidity is consistently high. Ant gardens retain moisture and support epiphyte growth.
  • Diapause: No, as a tropical species from low elevation, they do not require hibernation or winter rest.
  • Nesting: This is an arboreal species that builds ant gardens in tree crowns. In captivity, they need vertical space and structures they can build on. A naturalistic setup with cork bark, branches, or moss-covered surfaces works well. They will construct carton material similar to their natural gardens.
• Behavior: These ants are relatively peaceful and tolerant, they allow other ant species (Tapinoma, Pseudomyrmex) to nest in their gardens. Workers forage and tend scale insects for honeydew. They are arboreal and will traverse branches and leaves rather than ground surfaces. Their small size means escape prevention must be excellent, they can squeeze through tiny gaps. Workers have a defensive sting but are too small to penetrate human skin effectively.
• Common Issues: escape prevention is critical due to their very small size, use fine mesh and tight-fitting barriers, arboreal nature requires vertical climbing structures and space, they won't thrive in horizontal-only setups, humidity must be consistently high, dry conditions will cause colony decline, this species is not established in the antkeeping hobby, wild-caught colonies from their native range are the only source, they may refuse to establish if conditions don't mimic their ant garden environment

Ant Garden Biology

Crematogaster jardinero is one of the few true ant garden species in Costa Rica ^[2]. In the wild, these ants build remarkable structures in tree crowns, the nest material is a carton made by the ants that serves as a scaffold for growing epiphytes. Longino documented an archipelago of ant gardens in an Inga tree crown at 500m elevation in Braulio Carrillo National Park. The largest central garden was the oldest, and smaller gardens were scattered across adjacent tree crowns. The gardens supported about 20 epiphyte species including aroids (the most abundant), Piperaceae, Gesneriaceae, Bromeliaceae, and Orchidaceae. When the gardens were removed, the tree stems beneath were densely clustered with scale insects, these insects were completely absent from exposed stems, only occurring where sheltered by the carton material. This suggests the ants tend scale insects for honeydew, similar to many Crematogaster species.

Colony Structure and Brood Dispersion

This species has an unusual colony structure. When Longino dissected ten ant gardens (including the large central garden), he failed to find any concentrated area of brood or a physogastric queen. After completing the dissections, he found a single physogastric queen on his clothing, presumably shaken loose during the work. The presence of only one queen across ten gardens strongly suggests monogyne colony structure. More remarkably, workers, brood, males, and alate queens were dispersed evenly throughout the matrix of each garden, not clustered in one area. This dispersion pattern suggests the larvae may feed on something produced by the garden itself rather than relying on food brought to them by workers, similar to how fungus-growing ants (Attini) distribute larvae throughout their fungal gardens. This makes their colony organization fundamentally different from most ant species. ^[1]

Housing and Nest Setup

This is an arboreal species that requires vertical space and structures for building ant gardens. In captivity, provide a naturalistic setup with cork bark, branches, moss, or other surfaces they can build carton on. The setup should allow for high humidity while providing some ventilation. They will construct their nest material across multiple surfaces rather than confining to a single chamber. A tall formicarium or custom arboreal setup works better than horizontal test tube setups. Include live moss or epiphytes if possible, these replicate their natural ant garden environment. The ants will tend any scale insects present on their structures and may cultivate beneficial fungi. ^[1][2]

Feeding and Diet

Like other Crematogaster species, these ants likely feed on honeydew from scale insects and aphids, plus small insects. In the wild, their ant gardens harbored dense scale insect colonies beneath the carton material. In captivity, provide sugar water or honey occasionally, but their primary food should be small insects (fruit flies, pinhead crickets, small mealworms). They may accept honeydew substitutes. Feed small prey items 2-3 times per week, adjusting based on consumption. Remove uneaten prey after 24 hours to prevent mold. ^[1]

Temperature and Humidity

Keep these tropical ants warm at 22-26°C. They come from Costa Rican wet forests at 500m elevation where temperatures are consistently warm year-round. Avoid temperatures below 18°C as this could stress or kill the colony. High humidity is essential, their natural ant garden environment is constantly moist from rainforest conditions and the water-retention properties of the carton nest material. Maintain humidity around 70-80% using moist substrates and regular misting. However, ensure some ventilation to prevent mold growth, which can quickly destroy ant gardens. ^[1]

Behavior and Temperament

These ants are notably tolerant of other ant species, in the wild, small nests of Tapinoma and Pseudomyrmex were found living in dead sticks within the ant garden epiphytes without conflict. Workers are small and active, foraging along branches and leaves in the canopy. They have a small sting but it is too weak to penetrate human skin, making them essentially harmless to keepers. Their main defense is escaping into their nest structure. Due to their tiny size, excellent escape prevention is essential, even standard test tube barriers may not contain them. Use fine mesh and check all connections regularly. ^[1]

Frequently Asked Questions

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References