Crematogaster atra

Crematogaster atra

Crematogaster atra is a small to medium-sized ant species belonging to the Myrmicinae subfamily. Workers measure 0.77-0.84mm in head width and 0.74-0.78mm in mesosoma length, making them relatively small ants. They are characterized by a well-defined longitudinal striation on their face that follows the curvature of the eye, and short erect hairs covering most of the dorsal surface of their mesosoma. The sternopetiolar process (a small projection at the base of the petiole) is highly variable, ranging from absent to well-developed. This species is part of the Crematogaster crinosa complex and requires further taxonomic study to fully resolve its classification ^[1].

These ants are found across the Neotropical region, from central Mexico south to Argentina, inhabiting diverse environments ranging from desert shrubland to lowland rain forest. They are arboreal nesters in nature, commonly found nesting in trees and swollen thorn Acacia plants, though they also establish nests in soil including muddy clay with pebbles and various soil types from dark brown clay to white sand ^[1]. Their common name 'acrobat ant' comes from their ability to raise their gaster over their head when disturbed, a defensive posture typical of the Crematogaster genus.

Quick Summary

• Difficulty: Medium
• Origin & Habitat: Neotropical region, Mexico south to Argentina, including Brazil, Venezuela, Bolivia, Colombia, Paraguay, and Uruguay. Found in diverse habitats including desert shrubland, ravine riparian forest, oak woodland, scrubby disturbed rain forest, and lowland rain forest ^[1].
• Colony Type: Colony structure is not well documented for this specific species. Based on typical Crematogaster patterns, they likely form single-queen colonies (monogyne), though some related species can have multiple queens. More research needed on their exact colony structure.
  • Colony: Monogyne
  • Founding: Claustral
• Size & Growth:
  • Queen: Not directly measured for C. atra, estimated 5-7mm based on genus patterns
  • Worker: Workers 0.77-0.84mm head width,0.74-0.78mm mesosoma length ^[1]
  • Colony: Colony size is unconfirmed for this species, but related Crematogaster species typically reach several hundred to a few thousand workers
  • Growth: Moderate, based on typical tropical Crematogaster development
  • Development: Estimated 5-8 weeks at tropical temperatures (25-28°C) based on genus patterns (Development time is inferred from related tropical Crematogaster species. Warmer temperatures within the suitable range will accelerate development.)
• Antkeeping:
  • Temperature: Keep nest area at 25-28°C. These are tropical ants that prefer warm conditions. A gentle temperature gradient allows workers to self-regulate. Room temperature in heated homes (around 24-26°C) is often suitable. Avoid temperatures below 22°C for extended periods.
  • Humidity: Moderate to high humidity. Provide a moist nest substrate, they naturally nest in soil and trees in humid environments. Keep the nest substrate consistently damp but not waterlogged. Provide a water tube for drinking access.
  • Diapause: No, as a tropical species, they do not require hibernation. Maintain consistent warm temperatures year-round.
  • Nesting: They are arboreal and ground-nesting in nature. In captivity, they do well in acrylic nests, Y-tong nests, or naturalistic setups with soil. Provide nesting chambers with some moisture retention. They accept various nest types but prefer enclosed spaces with humidity control. A test tube setup works for founding colonies.
• Behavior: Crematogaster ants are known for their defensive behavior, when threatened, workers raise their gaster over their head like an acrobat, which gives them their common name. They have a functional stinger but it is small and primarily used against other insects. They are generally not aggressive toward humans but will defend their nest vigorously. Workers are active foragers and will search for food both on the ground and in vegetation. They are omnivorous, feeding on honeydew, small insects, and sweet substances. Their small size (under 1mm) means escape prevention should be a priority, use fine mesh barriers and tight-fitting lids.
• Common Issues: escape prevention is critical due to their very small size, they can squeeze through standard mesh, tropical temperature requirements mean they may struggle in unheated homes during winter, slow founding phase, claustral queens may take 4-8 weeks before first workers emerge, wild-caught colonies may carry parasites that can cause colony failure, overfeeding can lead to mold problems in nest setups

Housing and Nest Setup

Crematogaster atra can be kept in various nest types. For founding colonies, a simple test tube setup works well, fill the tube with water, plug with cotton, and place the queen in the dark. The queen will seal herself into a chamber and raise her first brood there. Once you have 20+ workers, you can consider moving to a more elaborate setup.

For established colonies, acrylic nests or Y-tong nests work well. These allow you to control humidity more precisely than naturalistic soil setups. Keep the nest substrate moist but not soggy, the ants should have access to both damp areas and slightly drier zones for self-regulation. A water tube attached to the outworld provides drinking water.

The outworld should be simple and easy to clean. These are small ants, so use a shallow foraging area to prevent prey from escaping. Fluon or vaseline barriers on the rim help prevent escapes. Because workers are under 1mm, even standard mesh can be insufficient, consider double barriers or fine mesh. ^[1]

Feeding and Diet

Crematogaster atra is omnivorous like most Crematogaster species. In captivity, they readily accept sugar sources including honey water, sugar water, and honey. Offer a constant supply of sugar water in a test tube with a cotton wick.

For protein, offer small insects. Fruit flies, small crickets, mealworms, and other appropriately-sized arthropods are accepted. Feed protein 2-3 times per week, adjusting based on colony size and brood production. Remove uneaten prey after 24-48 hours to prevent mold.

They will also collect honeydew if you haveaphids or scale insects available, though this is optional in captivity. Some keepers report that their Crematogaster colonies prefer liquid sugars and will ignore solid sugar, so honey water is usually the better choice.

Temperature and Seasonal Care

As a tropical species from the Neotropical region, Crematogaster atra requires warm temperatures year-round. Keep the nest area at 25-28°C for optimal brood development. Temperatures below 22°C for extended periods can slow development and weaken the colony.

A small heating cable or heating mat on one side of the nest can create a temperature gradient. Place the heating on top of the nest rather than underneath to avoid drying out the substrate through evaporation. Monitor with a thermometer to ensure temperatures stay in range.

Unlike temperate species, these ants do not require hibernation or diapause. Maintain consistent temperatures throughout the year. If your room temperature drops below 22°C in winter, consider using a small heater or heating mat to maintain warmth. ^[1]

Behavior and Defense

The most distinctive behavior of Crematogaster ants is their defensive posture, when threatened, workers raise their gaster over their head, ready to use their stinger. This 'acrobat' posture gives the entire genus its common name. They are not particularly aggressive toward humans but will defend their nest if disturbed.

Workers are active foragers and will search for food both in the outworld and in vegetation if given the opportunity. They communicate using chemical trails and can recruit nestmates to food sources.

Their small size means they are excellent climbers and can scale smooth surfaces. Escape prevention is essential, use vaseline or fluon barriers on all rim surfaces and ensure any mesh barriers are fine enough to contain workers under 1mm in length.

Colony Development and Growth

A newly mated queen will seal herself into a chamber and lay eggs. She feeds the larvae from her own metabolic reserves and does not leave to forage during founding, this is claustral founding behavior typical of Myrmicinae. The first workers, called nanitics, are typically smaller than normal workers.

Development from egg to worker likely takes 5-8 weeks at optimal tropical temperatures (25-28°C). This is inferred from related Crematogaster species as specific development data for C. atra is not available. Once the first workers emerge, the colony grows more steadily as the queen focuses on egg production and workers take over foraging and brood care.

Colony growth is moderate, you can expect several hundred workers within the first year under good conditions. Mature colonies of related species can reach several thousand workers. Growth rate depends heavily on temperature, feeding frequency, and colony health.

Frequently Asked Questions

References