Polyrhachis bubastes

Polyrhachis bubastes

Polyrhachis bubastes is a tropical ant species from the Moluccas Islands in Indonesia. Workers are medium-sized with the characteristic spines on the thorax that give Polyrhachis their common name of 'spiny ants.' They belong to the subgenus Myrmhopla (sexpinosa-group), which is known for arboreal nesting habits ^[1]. This species builds nests in trees using silk and carton material, a behavior shared with other weaver ants in the genus ^[1][2]. The presence of pupal cocoons is notable, as some Polyrhachis species have naked pupae ^[1].

Quick Summary

• Difficulty: Medium
• Origin & Habitat: Moluccas Islands, Indonesia, tropical arboreal habitat in rainforest environments ^[3]
• Colony Type: Colony structure is unconfirmed for this specific species. Most Polyrhachis species are monogyne (single queen), though some can be polygynous.
• Size & Growth:
  • Queen: Estimated 10-12mm based on genus typical sizes
  • Worker: Estimated 6-9mm based on subgenus Myrmhopla patterns
  • Colony: Likely several hundred workers based on related species
  • Growth: Moderate
  • Development: Estimated 6-8 weeks at tropical temperatures (25-28°C) based on genus patterns (Development time is inferred from related Polyrhachis species, not directly studied for this species)
• Antkeeping:
  • Temperature: Keep at 24-28°C. Tropical species require warm conditions year-round. A heating cable on one side of the nest can help maintain warmth
  • Humidity: High humidity (70-80%) is essential. Arboreal ants naturally experience humid conditions in the rainforest canopy. Mist the outworld regularly and keep nesting material moist but not waterlogged
  • Diapause: No, this is a tropical species that does not require hibernation. Maintain consistent warm temperatures year-round
  • Nesting: Arboreal species need vertical space and climbing structures. Y-tong nests or naturalistic setups with branches work well. They use silk to bind nesting materials, so provide suitable substrates like leaf pieces or cotton. Avoid fully enclosed test tube setups, they prefer more open, ventilated arrangements ^[1][2]
• Behavior: Generally peaceful and non-aggressive compared to many tropical ants. Workers are active foragers that search for honeydew and small prey. They are skilled climbers thanks to their arboreal origins. Escape risk is moderate, use standard barrier methods but they are not particularly prone to escaping like some tiny species. They may be skittish and flee when disturbed rather than attacking.
• Common Issues: tropical temperature requirements mean colonies can fail if kept too cool, arboreal nature means they need vertical space, horizontal setups may cause stress, high humidity needs can lead to mold problems if ventilation is poor, limited availability in the antkeeping hobby means founding colonies can be difficult, carton-nesting behavior requires specific materials that may not be readily available

Natural History and Distribution

Polyrhachis bubastes is found exclusively in the Moluccas Islands, an archipelago in eastern Indonesia. This tropical region features warm temperatures year-round and high humidity from frequent rainfall. As an arboreal species, P. bubastes nests in the rainforest canopy rather than on the forest floor. They construct nests using silk produced by the larvae and carton material made from chewed plant fibers, a characteristic shared with other Myrmhopla species ^[1][2]. The spines on their thorax are a defining feature of the genus and serve multiple purposes including defense and manipulation of nesting materials. Unlike some ants that have naked pupae, this species spins cocoons around their pupae before they develop into adult workers ^[1].

Nest Preferences and Housing

In captivity, P. bubastes needs an arboreal setup that mimics their natural tree-dwelling lifestyle. Provide vertical space with branches, twigs, or artificial climbing structures. Y-tong nests work well because they offer chambers the ants can adapt, but you should also add external climbing structures. The key requirement is providing materials they can bind with silk, dried leaves, cotton fibers, or small fabric pieces work as nesting material. Avoid fully enclosed test tubes as these arboreal ants prefer more open, ventilated spaces. The nest area should be kept humid while the outworld can have normal room humidity. Ensure the setup allows for vertical travel between chambers and foraging areas. ^[1][2]

Feeding and Diet

Polyrhachis ants are omnivorous like most ants in the genus. They naturally tend to honeydew-producing insects (aphids, scale insects) in the canopy and hunt small prey. In captivity, offer a varied diet: sugar water or honey as an energy source, and protein sources like small crickets, mealworms, or other insects. Fresh fruit can also be accepted. Feed protein 2-3 times per week and keep sugar water available constantly. Remove uneaten prey after 24 hours to prevent mold. Since they are arboreal foragers, place food on elevated platforms or branches rather than on the floor of the outworld.

Temperature and Humidity Requirements

As a tropical species from the Moluccas, P. bubastes requires warm and humid conditions. Keep the nest area at 24-28°C consistently, temperatures below 22°C can stress the colony and slow development. A small heating cable placed on one side of the nest can help maintain proper temperatures, but avoid direct heat that could dry out the nest. Humidity should remain high at 70-80%. The nesting material should feel consistently moist but never waterlogged. Mist the outworld regularly and consider using a water reservoir in the nest setup. Unlike temperate species, these ants do not need any cooling period or winter rest, maintain tropical conditions year-round.

Behavior and Colony Dynamics

Workers of P. bubastes are active and agile climbers. They are generally non-aggressive and will flee rather than attack when threatened. This makes them suitable for antkeepers who prefer observing interesting behavior over dealing with aggressive defenders. The colony will expand their nest by binding materials with silk, creating characteristic carton structures. Workers forage individually rather than in massive raiding parties. The colony likely grows to several hundred workers over time, though exact colony size is unknown for this species. Queens are claustral, they seal themselves in a chamber and survive on stored fat reserves until the first workers emerge.

Frequently Asked Questions

References