Simopelta transversa

Quick Summary

• Difficulty: Expert
• Origin & Habitat: Endemic to Pance, Valle del Cauca, Colombia, at about 1700m elevation in wet mountain rainforest (cloud forest) ^[1][3].
• Colony Type: Colony structure has not been formally documented. The single known observation involved one queen and a large raiding column, hinting at monogyny, but this is not confirmed.
• Size & Growth:
  • Queen: 6mm total length ^[1]
  • Worker: 4.5mm total length ^[1]
  • Colony: At least 1000 workers in wild raiding colonies ^[1]
  • Growth: Unknown, no captive data
  • Development: Unconfirmed (Development timeline has not been studied for this species.)
• Antkeeping:
  • Temperature: Inferred from high-elevation cloud forest habitat: 20-24°C. Monitor colony activity and adjust if needed.
  • Humidity: High humidity, aim for consistently moist (not waterlogged) nest substrate, similar to a damp forest floor.
  • Diapause: Unknown, no data on seasonal requirements. Their habitat may experience cooler periods, but diapause needs are unstudied.
  • Nesting: Inferred from observed bivouac behavior: they use temporary leaf nests during raids. A naturalistic setup with moist substrate and multiple chambers likely works, with space for maintaining prey colonies.
• Behavior: Aggressive specialized predator with a functional stinger. Fast-moving workers form organized raiding columns to attack Pheidole colonies. Highly active foragers. Moderate size and speed require good escape prevention. Stings are painful, handle with caution ^[2][1].
• Common Issues: extreme rarity, known only from one location in Colombia, almost certainly unavailable in the hobby, specialized diet, requires live Pheidole or similar small ants as prey, making feeding very difficult, no captive breeding data, all care advice is inferred from habitat, high humidity needs from cloud forest may be challenging to maintain, aggressive nature and painful sting make this unsuitable for beginners

Identification and Appearance

Simopelta transversa workers are moderately large (total length about 4.5mm), dark reddish-brown with lighter brown legs and gaster. The top of the head is covered with coarse transverse wrinkles (striae), the species name means "crosswise" in Latin, referring to these. Workers have unusually long, upright hairs on the outer surface of the hind tibiae, some as long as the leg's diameter. The petiolar node, viewed from above, is much broader than long, a rare shape in the genus. Mandibles have three teeth of about equal size ^[1][4].

Queens are larger (total length 6mm) with an enlarged gaster. Their mandibles are sickle-shaped without teeth, and the head is nearly round. The eyes are small, containing about ten poorly defined ommatidia, suggesting limited vision ^[1].

Distribution and Habitat

Known only from the type locality: Pance, municipality of Cali, Valle del Cauca, Colombia, at about 1700m elevation. The habitat is wet mountain rainforest (cloud forest) with high humidity, frequent mist, and moderate temperatures. The type colony was found on a steep slope along a large stream, among abundant leaf litter ^[1][3][5].

Feeding and Predatory Behavior

Simopelta transversa is a specialist predator that exclusively targets Pheidole ants ^[2]. In the wild, a colony was observed raiding a Pheidole nest: workers ran rapidly downhill through leaf litter, almost all carrying white pupae (and possibly a few larvae). They formed a bivouac, a temporary nest made from one leaf cupped beneath another, containing a mass of workers, brood, and prey. This coordinated raiding shows they can overwhelm larger prey through group attacks ^[1].

In captivity, you would need to maintain live Pheidole colonies for food. They are unlikely to accept standard ant foods, sugar water, or other non-ant protein sources.

Colony Structure and Size

The only documented wild colony was estimated at 1000 or more adult workers. The queen is known (6mm, enlarged gaster), but details about colony structure (monogyne vs polygyne) and whether replacement queens (ergatoids) exist have not been studied. Based on typical Ponerinae patterns, single-queen colonies seem likely, but this is unconfirmed ^[1].

Temperature and Care Requirements

From their cloud forest habitat at 1700m, Simopelta transversa needs cooler, more humid conditions than many tropical ants. Keep temperature around 20-24°C. Humidity should be high, nest substrate consistently moist but not waterlogged, with good ventilation to prevent mold.

No captive data exists, so all recommendations are inferred. Diapause needs are unknown. They have a functional Ponerine stinger and can deliver painful stings, handle with caution. ^[1]

Availability and Legal Considerations

Simopelta transversa is extremely rare, known only from one site in Colombia. There is no evidence of captive breeding or legal trade. It may be protected under Colombian law as an endemic species with a very restricted range. Interested keepers should instead consider more common specialist Ponerines like Odontomachus or Harpegnathos, which have established captive populations ^[1][3][5].

Frequently Asked Questions

Report an Issue

The current care sheet is based fully on literature. See inconsistencies, or something that's incorrect? Please report here, it will be resolved after review from an admin. Contributing to the blogs tab also helps providing information, to make us be able to further improve the caresheets. Thank you for your support!

References