Prolasius advena

Prolasius advena - "Small Brown Bush Ant"

Prolasius advena is a small, dark ant native to New Zealand, where it lives exclusively in native beech forests ^[1]. Workers are dark brown to black with a distinctive shiny appearance, and queens are slightly larger and more robust. This species belongs to the subfamily Formicinae, which means they lack a stinger and instead defend themselves by spraying formic acid. Originally described by Frederick Smith in 1862,this ant was once considered a separate species (Prolasius zealandica) before being recognized as the same species ^[2]. As a Melophorini member, they are related to the famous honey pot ants. These ants are endemic to New Zealand and are found throughout both the North and South Islands ^[2].

Quick Summary

• Difficulty: Medium
• Origin & Habitat: Native to New Zealand, specifically found in native beech forests across both North Island and South Island ^[1][2]. This temperate forest habitat provides cool, damp conditions with plenty of decaying wood and leaf litter.
• Colony Type: Colony structure is unconfirmed. Based on related Melophorini species, they likely form single-queen colonies, but this has not been directly studied.
• Size & Growth:
  • Queen: Estimated 5-7mm based on genus-level data from related Melophorini species
  • Worker: Estimated 3-5mm based on genus-level data
  • Colony: Unknown, no colony size data exists in the scientific literature
  • Growth: Moderate, based on typical Melophorini patterns
  • Development: Estimated 6-10 weeks at optimal temperature based on related Formicinae species (Direct development data does not exist for this species. Estimate based on typical temperate Formicinae development timelines.)
• Antkeeping:
  • Temperature: Keep around 18-22°C. As a New Zealand temperate species, they prefer cooler conditions than tropical ants. Room temperature is likely suitable for most keepers.
  • Humidity: Moderate to high, beech forests are damp environments. Keep the nest substrate consistently moist but not waterlogged. Provide some drier areas for the ants to choose between.
  • Diapause: Yes, New Zealand has distinct seasons, so a winter dormancy period is likely needed. Reduce temperature to around 10-15°C for 2-3 months during winter.
  • Nesting: In nature they likely nest in decaying wood, under bark, or in soil beneath leaf litter. In captivity, a naturalistic setup with soil and rotting wood, or a Y-tong/plaster nest with moisture retention works well.
• Behavior: These ants are generally calm and not aggressive. Like other Formicinae, they can spray formic acid when threatened, which is a mild irritant but not dangerous to humans. Workers are foragers that likely scavenge and tend aphids for honeydew. Their small size means escape prevention should be taken seriously, they can squeeze through small gaps. They are not particularly fast-moving compared to some tropical species.
• Common Issues: limited availability, this species is rarely available in the antkeeping hobby due to New Zealand export restrictions, escape prevention, their small size means they can escape through tiny gaps without proper barriers, humidity control, too dry and colonies will fail, too wet and mold becomes an issue, winter dormancy, failing to provide proper diapause may stress colonies, very limited care information, much of captive care is inferred from related species rather than direct study

Origin and Natural Habitat

Prolasius advena is endemic to New Zealand, found nowhere else in the world ^[2]. They inhabit native beech forests throughout both the North and South Islands, making their home in the cool, damp understory of these temperate forests ^[1]. In their natural habitat, they nest in decaying wood, under loose bark, or in soil rich with organic matter. The New Zealand beech forest environment is characterized by high humidity, moderate temperatures, and abundant leaf litter, conditions you should aim to replicate in captivity. The forest floor provides stable microclimates that stay cooler in summer and don't freeze hard in winter.

Temperature and Seasonal Care

As a temperate New Zealand species, Prolasius advena prefers cooler temperatures than many common ant pets. Keep the nest area in the range of 18-22°C year-round, with slight variations being tolerated. During the summer active season, room temperature is typically suitable. In winter, you should provide a dormancy period, reduce temperatures to around 10-15°C for 2-3 months. This mimics the natural seasonal cycle they experience in beech forests. A simple way to achieve this is to move the colony to a cooler location like an unheated garage or basement during winter months. Do not attempt to keep them active year-round as this can stress the colony and reduce lifespan.

Nesting and Housing

In the wild, Prolasius advena nests in decaying wood and soil beneath leaf litter, typical of forest-dwelling ants. For captivity, a naturalistic setup works well: a mix of soil and small pieces of rotting wood or leaf litter. Alternatively, a Y-tong (AAC) nest or moist plaster nest provides good humidity control. The key is maintaining consistent moisture without saturation. These ants are small, so ensure any setup has no large gaps that could allow escapes. A test tube setup can work for founding colonies, but you may need to move them to a larger formicarium as the colony grows.

Feeding and Diet

Like other Melophorini ants, Prolasius advena is likely omnivorous. In nature, they probably scavenge for protein sources and tend aphids for honeydew. In captivity, offer a varied diet: sugar water or honey water as a constant energy source, and protein sources like small insects (fruit flies, small mealworms, crickets) weekly. They may accept commercial ant gels or protein paste, but live prey is always best for protein. Fresh water should always be available. Start with small amounts and observe what your colony accepts, preferences can vary between colonies.

Behavior and Defense

Prolasius advena workers are relatively calm and not aggressive toward keepers. Like all Formicinae ants, they lack a stinger but can spray formic acid as a defense mechanism. This is a mild irritant rather than a dangerous toxin, it may cause minor skin irritation or a burning sensation but is not harmful to healthy humans. Workers are foragers that search for food rather than ambush predators. They are likely most active during cooler parts of the day in captivity. Their small size means they can be overlooked, but they are not particularly fast-moving.

Frequently Asked Questions

References