Stenamma felixi

Stenamma felixi

Stenamma felixi is a medium to large-sized ant species native to Central and South America, ranging from Mexico's Atlantic slope down to Ecuador ^[1]. Workers measure 0.81-1.04mm in head width with a body length around 1.25-1.62mm, making them notably robust compared to many other Stenamma species ^[2]. They have a distinctive appearance: mostly black to dark brown body with dense sculpturing on the head and mesosoma featuring sharp carinae and rugae, relatively large oval eyes, and notably lack propodeal spines, instead forming shallow blunt angles where the propodeal dorsum meets the declivity ^[1]. The species is one of the most widespread and common Stenamma species in Middle America, found exclusively in wet forest environments from lowland rainforest to cloud forest at elevations between 50-1600m, most commonly above 500m ^[2][1].

What makes S. felixi interesting is its nesting behavior in rotting wood and its colony structure. Nests are generally quite large and have been found in rotting logs on the ground, inside tree stumps, and under bark of logs, occasionally in mud banks ^[2]. All colonies collected so far have been monogynous, meaning they contain a single queen, which is relatively uncommon among Stenamma species ^[2]. Workers are epigeic, meaning they forage on the ground surface, typically hunting alone rather than in groups. You may spot lone workers running across logs in forest environments, which is a common experience with this species ^[3].

Quick Summary

• Difficulty: Medium
• Origin & Habitat: Wet forests from lowland rainforest to cloud forest, ranging from Mexico's Atlantic slope through Central America to Ecuador, at elevations of 50-1600m (most common above 500m) ^[2][1]
• Colony Type: Monogyne, single queen colonies. All colonies collected in the wild have been monogynous ^[2]. Founding type is unconfirmed, but based on typical Stenamma genus patterns, queens likely seal themselves in during founding (claustral).
  • Colony: Monogyne
• Size & Growth:
  • Queen: HL 1.00-1.17mm, HW 0.85-0.98mm, ML 1.45-1.75mm ^[2]
  • Worker: HL 0.90-1.19mm, HW 0.81-1.04mm, ML 1.25-1.62mm ^[2][1]
  • Colony: Large colonies, nests are described as generally quite large in the wild ^[2]. Estimated up to several hundred workers based on typical Stenamma colony sizes.
  • Growth: Moderate, based on typical Stenamma development patterns
  • Development: Estimated 6-10 weeks based on related Stenamma species and tropical ant development patterns at warm temperatures (Development time is inferred from genus patterns since specific data for S. felixi is not available. Tropical elevation species typically develop faster than temperate species.)
• Antkeeping:
  • Temperature: Keep at 22-26°C, they inhabit warm, humid tropical forests. Based on their elevation range (50-1600m), they can likely tolerate a range from 20-28°C, but aim for the mid-20s for optimal brood development ^[2].
  • Humidity: High humidity required, these are wet forest ants. Keep nest substrate consistently moist but not waterlogged. Provide a water gradient so ants can choose their preferred moisture level. Think damp forest floor conditions.
  • Diapause: Unlikely, as a tropical species from low to mid elevations, they probably do not require a true diapause. However, a slight reduction in temperature during winter months may slow activity naturally.
  • Nesting: In captivity, they do well in naturalistic setups with rotting wood pieces, or in Y-tong/plaster nests with high humidity. They naturally nest in rotting logs and tree stumps, so providing wood or cork in the setup mimics their natural nesting preferences ^[2]. A nest chamber should be appropriately sized for their medium-large size.
• Behavior: Workers are epigeic (ground-dwelling) solitary foragers, they hunt alone rather than in groups ^[2]. They are not particularly aggressive and will typically flee rather than engage. They have relatively large eyes and are active foragers. Escape risk is moderate, they're not tiny but can fit through small gaps. Use standard escape prevention. They are cryptic ants that may spend considerable time hidden in the nest structure.
• Common Issues: high humidity maintenance is critical, they are wet forest specialists and mold or drying can kill colonies, slow founding phase, like many Stenamma, claustral queens may take time to produce first workers, escape prevention needed despite medium size, they can squeeze through gaps in setups, wild-caught colonies may have parasites collected from their natural forest habitat, difficulty finding mates for breeding, nuptial flight timing in captivity is unknown

Housing and Nest Setup

Stenamma felixi does well in naturalistic setups that mimic their natural rotting wood habitat. Provide a setup with pieces of rotting wood, cork, or a Y-tong/plaster nest with high humidity chambers. The key is maintaining consistently damp conditions without flooding. Use a water reservoir or moisture gradient so ants can self-regulate their humidity preferences. Since they nest in rotting logs in the wild, adding small wood pieces or bark to a naturalistic formicarium helps them feel at home. They are medium to large ants, so chambers should be appropriately sized, not too cramped, but not overly spacious either. A test tube setup can work for founding colonies if kept humid, but transfer to a more spacious nest once the colony grows beyond 20-30 workers. ^[2][1][3]

Feeding and Diet

In the wild, S. felixi workers are epigeic solitary foragers, but their exact dietary preferences are unknown ^[2]. As a Myrmicinae ant, they likely are omnivorous, accepting both protein sources and carbohydrates. Offer a varied diet: small live insects (fruit flies, small crickets, mealworms) for protein, and sugar water or honey for carbohydrates. Since they're solitary foragers, place food in the outworld rather than expecting them to find hidden food. Feed protein 2-3 times per week and keep a constant sugar source available. Remove uneaten prey after 24-48 hours to prevent mold. Start with small prey items and adjust based on what workers accept.

Temperature and Seasonal Care

Keep your colony at 22-26°C, with a slight gradient allowing workers to choose their preferred temperature. These ants come from tropical wet forests in Central America, so they prefer warmth and humidity. A heating cable on one side of the nest can create the needed gradient, place it on top of the nest, not underneath, to avoid drying out the substrate. Since they occur from 50-1600m elevation, they can likely tolerate temperatures down to around 20°C, but growth and activity will be slower in cooler conditions. No true diapause is required, but you may notice reduced activity during winter months if room temperature drops. Avoid temperatures below 18°C or above 30°C. ^[2][1]

Colony Development and Growth

S. felixi colonies start with a claustral queen (likely, based on genus patterns) who seals herself in and raises the first brood alone. The founding phase can take several months, be patient. First workers (nanitics) will be smaller than mature workers. Colonies grow to become quite large in the wild, with nests described as generally quite large ^[2]. Expect moderate growth rate through the first year, with acceleration once the colony reaches 50+ workers. Since all wild colonies are monogynous, you should not need to worry about multiple queens. The colony will likely reach several hundred workers over 2-3 years under good conditions. Mating flights occur in the wild but the specific timing is unknown, in captivity, you may observe alates (reproductives) developing after the colony reaches substantial size.

Behavior and Observation

These ants are relatively calm and not aggressive. Workers are solitary foragers, meaning they hunt alone rather than forming raiding parties or recruiting nestmates en masse ^[2]. This makes them less exciting to watch during feeding times compared to species that use tandem running or chemical recruitment, but their large size and distinctive appearance make them interesting to observe. They have relatively large eyes for a Stenamma, which may indicate better vision. You may see workers actively patrolling the outworld, especially at night or during dim lighting conditions. They are cryptic by nature and may spend considerable time in the nest, so don't be concerned if you don't see constant activity. Provide a dark area or cover for the nest to reduce stress from constant light exposure.

Frequently Asked Questions

References