Cylindromyrmex brevitarsus

Cylindromyrmex brevitarsus

Cylindromyrmex brevitarsus is a small to medium-sized predatory ant belonging to the Dorylinae subfamily. Workers measure 4.20-6.44 mm with a distinctive elongated head bearing small eyes and mandibles equipped with 6-8 denticles ^[1]. The body is covered in fine longitudinal striations, giving them a textured appearance. Workers are light to dark brown, while queens are notably larger at 5.88-9.40 mm and appear darker, often black or dark brown ^[1]. This species inhabits wet tropical and cloud forests across Central and South America, from Mexico down to Brazil ^[2].

What makes Cylindromyrmex interesting is their position within the Dorylinae, they're relatives of army ants but don't form the massive swarming colonies typical of true army ants. Instead, they're cryptic predators that hunt individually or in small groups. They're rarely encountered by collectors, with most specimens coming from flight traps rather than direct nest collection ^[3]. This makes them a true rarity in antkeeping, as they're almost never available in the hobby.

Quick Summary

• Difficulty: Expert
• Origin & Habitat: Tropical Central and South America, found in Brazil, Colombia, Costa Rica, Ecuador, Guatemala, Mexico, Peru, Uruguay, and Venezuela. They inhabit montane wet forest, mesophil forest, mature cloud forest, and tropical moist forest ^[4].
• Colony Type: Unconfirmed colony structure. Based on related Dorylinae patterns, likely forms single-queen colonies, but this has not been directly documented.
• Size & Growth:
  • Queen: 5.88-9.40 mm (highly variable) ^[1]
  • Worker: 4.20-6.44 mm ^[1]
  • Colony: Unknown, likely small to moderate colonies based on cryptic forest-dwelling habits
  • Growth: Unknown, no captive breeding data available
  • Development: Unknown, no development studies exist for this species. Based on related Dorylinae patterns in tropical conditions, estimate 6-10 weeks at optimal temperature. (No direct data exists. Related Cerapachyini species suggest moderate development times. Temperature-dependent inference from tropical habitat.)
• Antkeeping:
  • Temperature: Keep warm at 24-28°C based on their tropical forest habitat. Use a heating cable on one side of the nest to create a gentle gradient.
  • Humidity: Require high humidity, think damp forest floor. Keep nest substrate consistently moist but not waterlogged. Aim for 70-80% relative humidity with good ventilation to prevent mold.
  • Diapause: Unknown, tropical species may not require formal hibernation, but may slow activity during cooler seasons.
  • Nesting: In nature they nest in rotting wood and leaf litter in forest floors. In captivity, a naturalistic setup with moist substrate (soil/peat mix) in a shallow container works well, or a plaster/acrylic nest with high humidity chambers. They prefer dark, concealed spaces.
• Behavior: These ants are cryptic and secretive. Workers are not aggressive and will flee from disturbance rather than confront. They're predatory, using their mandibles to capture small arthropods. Workers are small enough to pose minimal sting risk to humans. Escape risk is moderate, they're not particularly fast but will exploit any gaps in setup. They're nocturnal or crepuscular hunters based on their small eyes and forest-floor lifestyle.
• Common Issues: availability is extremely limited, this species is rarely collected and almost never available in the antkeeping hobby, no captive breeding data exists, keepers will be pioneers with no established protocols, high humidity requirements can lead to mold problems if ventilation is inadequate, tropical species may be sensitive to temperature drops, maintain consistent warmth, predatory diet means they need constant access to live small prey, cannot survive on sugar alone

Housing and Nest Setup

Cylindromyrmex brevitarsus requires a setup that mimics their natural forest-floor habitat. A naturalistic terrarium works best, use a shallow container filled with moist soil or peat mixed with rotting wood pieces and leaf litter. This provides both nesting sites and hunting grounds. The substrate should stay consistently damp but never waterlogged. Add pieces of flat bark or stones to create dark, concealed spaces where ants can nest. A small water reservoir connected to the substrate helps maintain humidity. Cover the setup well, while not strong climbers, they're small enough to slip through small gaps. Keep the setup in a dark location or provide minimal light, as these ants prefer dark conditions.

Feeding and Diet

As predatory Dorylinae, they need a protein-based diet. Offer small live prey appropriate to their size: fruit flies, springtails, tiny crickets, and other small insects. Feed every 2-3 days, removing uneaten prey to prevent mold. Unlike many ants, they're likely strict predators and may not accept sugar sources. Some keepers report success with occasional honey or sugar water, but protein should form the bulk of their diet. The small worker size (4-6mm) means prey must be tiny, they're not taking down large insects. Observe your colony's hunting behavior in low light conditions.

Temperature and Humidity

Maintain temperatures of 24-28°C year-round, mimicking their tropical forest habitat. A heating cable under one end of the nest creates a temperature gradient. They cannot tolerate cool temperatures, below 20°C for extended periods will stress and potentially kill the colony. High humidity is critical, aim for 70-80% relative humidity. Mist the substrate regularly and use a water reservoir. Good ventilation is necessary to prevent mold, but avoid creating drafts that dry out the setup. A hygrometer helps monitor conditions. If condensation forms heavily on the walls, increase ventilation slightly.

Behavior and Colony Dynamics

This is a cryptic, secretive ant. Workers are not aggressive and will hide at the first sign of disturbance. They're likely nocturnal or crepuscular hunters based on their small eyes. Colonies are probably small, perhaps 50-200 workers in established nests. Unlike army ants, they don't form massive foraging swarms. Instead, individual workers or small groups hunt for small prey. Queens are significantly larger than workers (5.88-9.40mm) and may be claustral founders. No data exists on colony reproduction or nuptial flight timing. Expect slow, steady growth with no dramatic population explosions.

Frequently Asked Questions

References