Doleromyrma rottnestensis

Doleromyrma rottnestensis

Doleromyrma rottnestensis is a tiny ant species native to Western Australia, specifically Rottnest Island near Perth. Workers measure just 1-1.5mm, making them one of the smaller ants you can keep ^[1]. They have a distinctive reddish-brown coloration with a darker head, and unlike many similar-looking small ants, they have a notably longer, more rectangular head shape and larger eyes that set them apart from the related Tapinoma species ^[2]. The mandibles have 5 distinct teeth, and they feature long clypeal setae that almost reach the base of their closed mandibles ^[1]. This species was originally described as Doleromyrma rottnestensis in 1934 before being transferred to Doleromyrma in 2009 ^[1].

What makes this species interesting is its limited geographic range, it's endemic to the Rottnest Island region off the coast of Western Australia, making it a relatively rare find in the antkeeping hobby. As a Dolichoderine ant, they belong to the same subfamily as the well-known Argentine ants and ghost ants, though their behavior is quite different.

Quick Summary

• Difficulty: Easy
• Origin & Habitat: Rottnest Island and surrounding Western Australia coastal areas. They nest under stones in beach environments and sandy substrates ^[2].
• Colony Type: Single-queen (monogyne) colonies based on typical Dolichoderinae patterns. Each colony has one founding queen that establishes the nest alone.
  • Colony: Monogyne
  • Founding: Claustral
• Size & Growth:
  • Queen: Estimated 4-5mm based on genus patterns (not directly measured in available literature)
  • Worker: 1-1.5mm ^[1]
  • Colony: Likely several hundred workers based on typical small Dolichoderinae colony sizes
  • Growth: Moderate, typical for small ants
  • Development: Estimated 6-8 weeks at optimal temperature based on related Dolichoderinae species (Development time is estimated from related species in the subfamily, specific timing for this species has not been documented)
• Antkeeping:
  • Temperature: Keep at 22-26°C. Being from a coastal Australian island, they prefer warm conditions but not extreme heat. Room temperature within this range works well, with a slight gradient if possible.
  • Humidity: Moderate humidity around 50-60%. Being from beach areas, they can tolerate some dryness but prefer substrate that dries out slowly. Provide a water tube as their primary moisture source.
  • Diapause: Likely minimal or no true diapause. Western Australia has mild winters, so they may reduce activity but not enter full hibernation. A slight cooling period to 15-18°C for 4-6 weeks in winter may be beneficial.
  • Nesting: They do well in test tubes for founding colonies. Once established, they adapt to various nest types including Y-tong, acrylic, or plaster nests. Their small size means narrow chambers work well.
• Behavior: Generally peaceful and non-aggressive. Workers are small and quick-moving, foraging actively for small prey and honeydew. They are not known to sting and pose no danger to keepers. Their escape risk is high due to their tiny 1mm size, they can squeeze through remarkably small gaps. Excellent escape prevention is essential: use tight-fitting lids, fine mesh barriers, and reliable barrier methods like fluon. They are active foragers and will readily explore their outworld.
• Common Issues: escape prevention is critical due to their tiny 1mm size, they squeeze through gaps that larger ants cannot, colonies can be slow to establish initially, patience is needed during the founding phase, test tube setups must have properly secured cotton and tight-fitting barriers, their small size makes them easy to overlook when checking on colonies, overheating is a risk, keep away from direct heat sources and strong sunlight

Housing and Setup

For founding colonies, a simple test tube setup works perfectly. Fill a test tube one-third with water, push cotton to create a water reservoir, then add the queen and seal with a tight-fitting cotton stopper. Place the tube in a dark, quiet location and leave it alone for 4-6 weeks until the first workers emerge. Once you have 10-20 workers, you can move them to a formicarium. Given their tiny 1mm size, any formicarium must have excellent escape prevention, tight-fitting lids, fine mesh on any ventilation, and barrier tape or fluon on edges. A Y-tong nest with narrow chambers or a small acrylic nest works well. They don't need large spaces, small, appropriately scaled chambers are actually better for their security. ^[1]

Feeding and Diet

Like most Dolichoderinae ants, Doleromyrma rottnestensis is omnivorous with a preference for sweet liquids and small protein sources. Offer sugar water, honey, or diluted maple syrup as a constant carbohydrate source. For protein, small live prey works best, fruit flies, pinhead crickets, small mealworms, or other tiny insects. Being such small ants, their prey items should be appropriately sized. They will also likely tend aphids if available, so honeydew is a natural food source. Feed protein 2-3 times per week, and keep sugar water available at all times. Remove any uneaten prey after 24 hours to prevent mold.

Temperature and Seasonal Care

Maintain temperatures between 22-26°C for optimal colony health and development. They come from a coastal island with mild temperatures, so they don't need extreme heat. A room-temperature setup is usually sufficient. In winter, a slight reduction to around 18-20°C is appropriate, but avoid cold temperatures below 15°C. They likely don't require a true hibernation period given Western Australia's mild climate, but a slight cooling during winter months may help simulate natural conditions. Watch for behavioral changes, if workers become sluggish, slightly warm one side of the nest to create a gradient.

Escape Prevention

This is the single most important aspect of keeping Doleromyrma rottnestensis. At just 1mm in length, they are exceptional escape artists. They can squeeze through gaps as small as 0.5mm, meaning standard ant keeping setups may not contain them. Use only high-quality, tight-fitting lids on all containers. Apply fluon or barrier tape to all edges and rim surfaces. If using a formicarium, ensure all connections and tube openings are sealed with cotton or plug-style barriers. Never leave the colony unattended with any opening, no matter how small it appears. When observing, work over a white surface so you can spot any escapees easily.

Colony Development

A newly mated queen will dig a small chamber and seal herself inside, this is claustral founding, typical of Dolichoderinae. She uses stored fat reserves to survive and feed her first brood. After 4-6 weeks, the first workers (called nanitics) will emerge. These initial workers are typically smaller than mature workers but will immediately begin foraging to support the colony. Growth is moderate, expect several months to reach 30-50 workers, and a year or more to reach several hundred. Colonies remain relatively small compared to species like Lasius or Camponotus. The queen is long-lived and will continue producing workers for years.

Frequently Asked Questions

References