Pristomyrmex umbripennis

Pristomyrmex umbripennis

Pristomyrmex umbripennis is a medium-sized ant species native to New Guinea. Workers measure 5.33-6mm and are reddish in color with blackish clypeus and mandibular margins. They have a distinctive smooth, shiny appearance with sparse deep round foveae (small pits) across the head and thorax, each containing a short erect hair. The thorax has a continuous convex dorsum without spines or teeth on the pronotum, though the metanotum bears small erect teeth. Queens are slightly larger at 7mm and are wingless (ergatoid), making them distinct from typical winged ant queens. This species is part of the Pristomyrmex genus, known for their predatory habits and distinctive head morphology.

Quick Summary

• Difficulty: Medium
• Origin & Habitat: New Guinea region, specifically documented from Andai in New Guinea ^[1]. Found in tropical forest habitats.
• Colony Type: Likely monogyne (single queen) based on typical Pristomyrmex patterns. The queen is ergatoid (wingless), which may indicate specialized colony structure with replacement reproductives.
  • Colony: Monogyne
• Size & Growth:
  • Queen: 7mm ^[1]
  • Worker: 5.33-6mm ^[1]
  • Colony: Estimated up to 200-500 workers based on typical Pristomyrmex colony sizes
  • Growth: Moderate, estimated based on genus patterns
  • Development: Estimated 6-8 weeks based on related Myrmicinae species at optimal temperature (Development timeline not directly studied, estimate based on genus patterns for medium-sized Myrmicinae)
• Antkeeping:
  • Temperature: Keep at 24-28°C, tropical species requiring warm conditions. A heating cable on one side of the nest creates a suitable gradient.
  • Humidity: Maintain moderate to high humidity (60-80%). Keep the nest substrate consistently moist but not waterlogged.
  • Diapause: No, tropical species does not require hibernation
  • Nesting: Y-tong (AAC) nests or plaster nests work well. Provide moist substrate and narrow chambers scaled to their medium size. They do well in naturalistic setups with some soil depth.
• Behavior: Pristomyrmex umbripennis is predatory by nature. Workers are active foragers that hunt small invertebrates. They are not aggressive toward humans but may bite if handled. Their medium size (5-6mm) makes them visible and engaging colony residents. Escape prevention should be standard, they are not particularly known for escaping but medium-sized ants can climb smooth surfaces.
• Common Issues: tropical humidity requirements mean mold can be an issue if ventilation is poor, predatory diet means they need regular protein input, sugar alone will not sustain the colony, ergatoid queen means colony growth may be slower than typical claustral founders, medium size means they need appropriately sized prey items, tropical species are sensitive to temperature drops, keep away from cold drafts

Housing and Nest Setup

Pristomyrmex umbripennis does well in Y-tong (acrylic) nests or plaster nests with moisture chambers. The queen is ergatoid (wingless), which is unusual and may affect how the colony establishes. Provide narrow chambers scaled to their medium size (5-6mm workers). A naturalistic setup with some soil depth also works well, as this species likely nests in soil or decaying wood in the wild. Keep one side of the nest slightly heated using a heating cable or mat to create a temperature gradient. The nest area should stay consistently moist but avoid standing water. ^[1]

Feeding and Diet

Pristomyrmex species are predatory by nature. Your colony will need regular protein from small live or frozen invertebrates. Offer small insects like fruit flies, pinhead crickets, mealworms, or waxworms. You can also try small spiders or other micro-arthropods. Sugar sources like honey water or sugar water should be available, though protein is the primary dietary need. Feed protein 2-3 times per week, and keep sugar water constantly available. Remove uneaten prey after 24 hours to prevent mold.

Temperature and Humidity

As a tropical species from New Guinea, Pristomyrmex umbripennis needs warm and humid conditions. Maintain temperatures between 24-28°C. A heating cable on one side of the nest creates a gradient that allows the ants to regulate their own temperature. Humidity should be moderate to high (60-80%). Keep the nest substrate consistently moist, it should feel damp to the touch but not be waterlogged. Good ventilation is important to prevent mold while maintaining humidity. ^[1]

Colony Development

The queen is ergatoid (wingless), measuring 7mm, this is significantly larger than the workers (5.33-6mm). This suggests the colony may have different founding dynamics than typical ants. Instead of nuptial flights, ergatoid queens may found colonies through different means such as budding or fission from an established colony. Expect slower initial growth compared to claustral species. Maximum colony size is estimated at 200-500 workers based on typical Pristomyrmex patterns. The development timeline from egg to worker is estimated at 6-8 weeks at optimal temperature. ^[1]

Behavior and Temperament

These ants are active foragers with predatory instincts. Workers will hunt small invertebrates within the outworld. They are not particularly aggressive and pose no real danger to keepers, though they may bite if provoked. Their medium size makes them engaging to watch. Standard escape prevention measures (fluon barriers, tight-fitting lids) are sufficient. They are diurnal and will show regular activity patterns throughout the day. The colony will likely establish a foraging trail once workers mature.

Frequently Asked Questions

References