Myrmecina australis

Myrmecina australis

Myrmecina australis is a tiny Australian ant species, measuring just 0.7-0.8mm in head length ^[1]. Workers are dark brown-black with yellow-brown antennae, mandibles and legs. The most distinctive feature is the first segment of the funiculus (antenna), which is expanded laterally and nearly spherical in shape, this unique morphology sets them apart from all other Australian Myrmecina species ^[1]. This is the southern-most species of Myrmecina found in Australia, occurring across a wide range of habitats from dry sclerophyll woodlands through wet sclerophyll forests, Nothofagus and Dicksonia fern forests, and into rainforest ^[1][2].

These are uncommon ants most often encountered in leaf litter samples in forested areas ^[2]. What makes them particularly interesting is their specialized diet, Myrmecina species are thought to be predatory on oribatid mites, with their larvae having exceptionally small heads adapted for feeding on the partially opened bodies of these tiny mites ^[2]. This specialized feeding requirement is the most important thing to understand for keeping this species successfully in captivity.

Quick Summary

• Difficulty: Medium
• Origin & Habitat: Southern Australia, this is the southern-most Myrmecina species in Australia, found in various forested habitats from dry sclerophyll woodlands through wet sclerophyll, Nothofagus and Dicksonia forests into rainforest ^[1][2]. Most specimens have been found in leaf litter samples or under rocks ^[1].
• Colony Type: Small colonies living in soil with or without coverings, between rocks, in twigs on the ground, or in rotten wood ^[2]. Colony structure is unconfirmed, the founding behavior and queen number has not been directly studied.
• Size & Growth:
  • Queen: Unconfirmed, queen measurements not available in current literature
  • Worker: 0.70-0.80mm head length (HL),0.69-0.83mm head width (HW) ^[1]
  • Colony: Small colonies, exact maximum unknown but colonies are described as small ^[2]
  • Growth: Unknown, development timeline has not been directly studied
  • Development: Unknown, no direct development data available for this species. Based on typical Myrmicinae patterns, expect 6-10 weeks at optimal temperature, but this is an estimate. (No specific development studies exist for M. australis. Related Myrmecina species suggest slow growth due to specialized dietary needs.)
• Antkeeping:
  • Temperature: Keep at room temperature, roughly 20-24°C. This species occurs in temperate to subtropical Australian forests, so moderate temperatures are appropriate. Avoid extremes, a stable room temperature within this range should work well.
  • Humidity: Moderate to high humidity, they naturally occur in leaf litter and forest floor environments that retain moisture. Keep the nest substrate consistently moist but not waterlogged. The substrate should feel damp to the touch with some slightly drier areas available.
  • Diapause: Unknown, Australian temperate species may have reduced activity in cooler months, but specific diapause requirements have not been documented.
  • Nesting: These ants naturally nest in soil, under rocks, in twigs on the ground, or in rotten wood ^[2]. For captivity, a small test tube setup or a Y-tong (AAC) nest with narrow chambers works well given their tiny size. A naturalistic setup with moist substrate and small hiding structures mimics their natural leaf litter environment. Keep chambers small and passages narrow, these are very tiny ants.
• Behavior: These are docile, non-aggressive ants that forage in leaf litter. They are not known to sting and pose no danger to keepers. Their small size means escape prevention is critical, they can easily slip through standard test tube barriers. They are specialized predators on oribatid mites, so their foraging activity is focused on hunting these tiny prey rather than scavenging. Workers are most active in the evening and night hours when mite activity is highest.
• Common Issues: tiny size makes escape prevention challenging, use fine mesh and tight-fitting barriers, specialized diet on oribatid mites may be difficult to replicate in captivity, live micro-prey is essential, small colony size means slow population growth and higher vulnerability to stress, wild-caught colonies may have parasites that are difficult to detect and treat, overfeeding can lead to mold problems in their small nests

Housing and Nest Setup

Given their tiny size (under 1mm), Myrmecina australis needs carefully scaled housing. A small test tube setup works well for founding colonies, use a standard test tube with a cotton ball creating a water reservoir, but ensure the chamber is small enough that the queen and workers can easily navigate. For established colonies, a Y-tong (AAC) nest with narrow chambers or a small naturalistic setup with moist substrate is appropriate.

These ants naturally live in soil, under rocks, in twigs, and in rotten wood ^[2]. In captivity, provide a moist substrate that can hold humidity, a mixture of soil and sand works well. Add small hiding structures like small pieces of bark or stones to mimic the leaf litter environment they naturally inhabit. Because they are so small, even tiny gaps in equipment can become escape routes, use fine mesh for any ventilation and ensure all connections are tight.

Lighting should be low, these are cryptic ants that prefer dark, humid microhabitats. Avoid direct sunlight on the nest area.

Feeding and Diet - The Critical Factor

This is the most important aspect of keeping Myrmecina australis successfully. In the wild, these ants are specialized predators on oribatid mites ^[2]. Their larvae have exceptionally small heads, an adaptation specifically for feeding on the partially opened bodies of these tiny mites ^[2]. This specialized diet is not optional, it appears to be a key biological requirement.

In captivity, you will need to culture or obtain live oribatid mites. These are tiny soil mites that can be collected from forest floor leaf litter or purchased from suppliers. Other small micro-arthropods like springtails may be accepted experimentally, but oribatid mites should be the primary food source. Do not rely on sugar sources or standard ant feeds, these ants are specialized predators, not generalists.

Feed small amounts of prey regularly, removing any uneaten prey after 24-48 hours to prevent mold. The hunting behavior is part of their natural activity pattern, so allow them to actively hunt rather than just providing pre-killed prey.

Temperature and Seasonal Care

Myrmecina australis occurs across a range of Australian habitats from temperate sclerophyll forests to subtropical rainforest ^[1]. This suggests they can tolerate a range of conditions, but moderate temperatures are ideal. Aim for roughly 20-24°C, this covers typical room temperature in most homes.

Avoid temperature extremes. Do not place the nest in direct sunlight or near heating vents. A stable temperature is more important than precise control. If your room temperature falls outside this range, a small heating mat on one side of the nest can create a gentle gradient, but monitor carefully to avoid overheating.

Specific seasonal requirements like diapause have not been documented for this species ^[1]. Australian temperate ants may have reduced activity in winter months, but this species occurs in areas with mild winters. Simply reducing feeding and activity during cooler months is likely sufficient, do not force hibernation unless you observe clear dormancy behavior.

Handling and Observation

These ants are extremely small and delicate. Handling them directly is not recommended, the risk of injury or death to the ants is very high. If you need to move them (for example, to a new nest), use soft brushes or allow them to walk into transfer containers rather than picking them up.

Observation is best done through the nest walls. Use a magnifying glass or macro lens on your phone camera to get a good look, their tiny size means you won't see much detail with the naked eye. Their dark coloration with yellow-brown antennae and legs is distinctive, and the spherical first funicular segment can be seen with magnification.

Because they are cryptic and spend most of their time in the nest or under cover, you may not see much activity. This is normal, they are not a showy species. The interesting behavior happens at the micro scale, particularly their mite-hunting activity.

Frequently Asked Questions

References