Polyrhachis lombokensis

Polyrhachis lombokensis

Polyrhachis lombokensis is a tropical arboreal ant belonging to the subgenus Myrmatopa. Workers are modest in size with the characteristic hooked spines on the thorax that many Polyrhachis species display. This species originates from the Australasian region, specifically New Guinea and surrounding islands of Indonesia. They are arboreal nesters, constructing their homes in trees using silk to bind leaves or other materials together, a behavior common to the Myrmatopa subgenus. Unlike many ants, they do not spin cocoons around their pupae, which is a distinctive trait of this group ^[1][2].

These ants are part of a genus known for their diverse nesting behaviors and often colorful appearance. P. lombokensis represents a relatively understudied species in the hobby, making it an interesting choice for antkeepers who want to work with a less common tropical arboreal species. Their arboreal nature means they require different housing approaches compared to typical ground-nesting ants.

Quick Summary

• Difficulty: Medium
• Origin & Habitat: New Guinea and Indonesia (Lombok Island). Tropical rainforest environment, they live in trees and construct silk-bound nests among foliage ^[1][2].
• Colony Type: Likely single-queen colonies based on typical Polyrhachis patterns. They build multiple nests within their territory, which is common for arboreal species in this genus ^[1][2].
• Size & Growth:
  • Queen: Estimated 8-10mm based on genus patterns for Myrmatopa species
  • Worker: Estimated 5-7mm based on genus descriptions
  • Colony: Likely moderate colonies of several hundred workers based on related Polyrhachis species
  • Growth: Moderate, tropical species with year-round activity
  • Development: Estimated 6-8 weeks at tropical temperatures (25-28°C), based on typical Formicinae development (Development is likely faster than temperate species due to tropical origin)
• Antkeeping:
  • Temperature: Keep at 24-28°C. Tropical species require warm, stable conditions year-round. A heating cable on one side of the nest creates a gentle gradient
  • Humidity: High humidity (70-85%) is essential. These rainforest ants need consistently moist conditions. Mist the outworld regularly and keep nest materials damp but not waterlogged
  • Diapause: No, tropical ants do not require hibernation. They remain active year-round if kept warm
  • Nesting: Arboreal specialists, they need vertical space and climbing structures. A naturalistic setup with live plants, branches, or cork bark works well. They will construct silk nests between surfaces. Alternatively, a Y-tong or acrylic nest with horizontal chambers and multiple climbing platforms can work ^[1][2]
• Behavior: Generally peaceful and non-aggressive compared to some Polyrhachis species. They are arboreal and spend most of their time climbing on vegetation and structures. Workers forage actively and will explore vertical spaces readily. They are not known for stinging and pose no danger to keepers. Their small size and arboreal lifestyle mean escape prevention is important, they can climb smooth surfaces easily. They use silk to bind nest materials together, which is a unique behavior worth observing ^[1][2].
• Common Issues: tropical temperature requirements mean colonies can slow down or die if kept too cool, arboreal nature means they need vertical space, standard horizontal nests may not suit them, high humidity needs can lead to mold problems if ventilation is poor, silk-nesting behavior requires appropriate materials, they need surfaces to bind together, small size and climbing ability make escape prevention critical

Housing and Nest Setup

Polyrhachis lombokensis requires housing that respects their arboreal lifestyle. Unlike ground-nesting ants that need horizontal space, these ants want to climb and build vertically. A naturalistic setup works best, include live plants, branches, cork bark pieces, or artificial leaves that they can connect with silk. The outworld should have multiple climbing surfaces and vertical structures.

For formicarium options, Y-tong nests with horizontal or slightly angled chambers can work, but you must provide extensive climbing enrichment in the outworld. Acrylic nests with multiple levels and platforms are also suitable. Whatever setup you choose, ensure there are plenty of surfaces close together that the ants can bind with silk, this is essential for their natural nesting behavior. The nest area should be humid while the outworld can be drier with regular misting ^[1][2].

Feeding and Diet

Polyrhachis ants are typically generalist feeders. Offer a varied diet including sugar sources (honey water, sugar water) and protein (small insects like fruit flies, small crickets, mealworms). In the wild, arboreal Polyrhachis species often forage in trees and may tend aphids or collect honeydew from homopterans.

Feed sugar water or honey once or twice weekly as a constant energy source. Offer protein prey 2-3 times per week, adjusting based on colony size. Remove uneaten prey after 24-48 hours to prevent mold. Since they are arboreal foragers, place food on elevated surfaces or platforms in the outworld rather than on the ground. This matches their natural foraging behavior and makes food discovery easier for the colony.

Temperature and Humidity Management

As a tropical species from New Guinea, P. lombokensis needs warm and humid conditions. Maintain temperatures between 24-28°C year-round. A heating cable placed on one side of the nest creates a temperature gradient that allows the ants to regulate their own conditions. Avoid temperatures below 22°C as this can slow colony development and make ants sluggish.

Humidity should remain high at 70-85%. Use a water reservoir in the nest setup and mist the outworld regularly. However, balance humidity with adequate ventilation to prevent mold growth, stagnant, overly humid conditions cause fungal problems. The nest substrate should be consistently moist but never waterlogged. These ants are adapted to rainforest conditions and will not thrive in dry environments.

Colony Development and Growth

Colony growth follows typical Formicinae patterns. A newly mated queen will seal herself in a chamber and lay eggs after establishing her founding claustrum. The first workers (nanitics) will be smaller than mature workers and emerge after approximately 6-8 weeks at optimal temperatures. After the first workers arrive, the colony enters a growth phase.

Growth rate is moderate, faster than temperate species but not as rapid as some tropical specialists. A healthy colony may reach several hundred workers over 1-2 years. Unlike species with cocoons, the pupae are naked, which means you may see the developing brood more clearly. Provide consistent warmth and nutrition to support steady growth. Colonies are likely permanent residents in their nests, building multiple connected shelters within their territory ^[1][2].

Unique Behaviors and Observations

The most distinctive behavior of P. lombokensis is their use of silk to construct nests. Workers bind leaves, debris, or other materials together using silk produced by their larvae, a behavior shared with other Myrmatopa subgenus species. In captivity, you can observe this by providing materials like cotton, small leaves, or paper strips that the ants will bind together.

They are arboreal by nature, spending most of their time climbing rather than walking on flat surfaces. This makes them fascinating to watch as they explore vertical spaces. They are not aggressive and do not pose sting risk to keepers. Their multiple-nest colony structure means they may use several different areas within their enclosure for different purposes, some for brood rearing, others for food storage or resting. ^[1][2]

Frequently Asked Questions

References