Zasphinctus steinheili

Zasphinctus steinheili

Zasphinctus steinheili is a predatory ant native to Australia, belonging to the Dorylinae subfamily, the same group that includes army ants. Workers are slender ants with distinctive abdominal constrictions that give them a segmented appearance. They measure around 4-6mm and have a dark reddish-brown coloration. These ants are myrmecophagous, meaning they specialize in raiding the nests of other ant species, feeding on their larvae and adults ^[1]. Colonies contain 100-500 workers and are polygynous, meaning they have multiple queens that are wingless (ergatoid queens) ^[1].

What makes Zasphinctus steinheili fascinating is their raiding behavior, they conduct organized raids against other ant colonies, similar to army ants but not as extreme. One observed raid in Victoria targeted a Stigmacros species, with the raiders running across bare soil while using cracks in the earth as cover. They appear to use chemical 'propaganda' substances to panic and scatter the defending ants, much like slave-making ants in the Northern Hemisphere. This group foraging is an army-ant-like trait, though they haven't evolved the full army ant syndrome ^[2].

Quick Summary

• Difficulty: Medium
• Origin & Habitat: Eastern Australia, including Queensland, New South Wales, Victoria, and Tasmania. Found in sclerophyll forest communities and rainforest areas at elevations from 200-1200m ^[3][4].
• Colony Type: Polygynous colonies with multiple ergatoid (wingless) queens. Studies show colonies can have 9-20 queens, with 20 ergatoid queens documented from 3 colonies. Queens are wingless and serve as replacement reproductives within the colony.
  • Colony: Polygyne
• Size & Growth:
  • Queen: Ergatoid queens are wingless, size not explicitly measured in available literature ^[3]
  • Worker: 4-6mm estimated based on genus ^[3]
  • Colony: 100-500 workers ^[1]
  • Growth: Moderate, based on related Cerapachys species showing phasic reproduction
  • Development: Unknown, no specific development data available for this species. Estimates based on related doryline ants suggest 6-10 weeks at optimal temperature. (Related Cerapachys species show phasic reproduction patterns with 80-400 worker colonies. Development time is likely temperature-dependent.)
• Antkeeping:
  • Temperature: Keep at 22-26°C. These are Australian ants that prefer warm conditions. A heating cable on one side of the nest can create a gradient if room temperature is below this range.
  • Humidity: Moderate humidity around 50-70%. Colonies nest in soil in the wild, so keep the nest substrate moist but not waterlogged. Allow for some drier areas so ants can self-regulate.
  • Diapause: Likely, Australian temperate species may require a mild winter rest period. Reduce temperature to 15-18°C for 2-3 months during winter.
  • Nesting: Soil-nesting species. Use a naturalistic setup with moist soil or a Y-tong/plaster nest with chambers scaled to their medium size. They prefer dark, humid nest chambers.
• Behavior: These are predatory ants with an active raiding style. Workers will organize group forays to raid other ant nests, targeting brood and adults. They are not aggressive toward humans but will defend their nest vigorously. Escape risk is moderate, use standard barrier methods. Workers are moderately fast-moving and will investigate their outworld actively. They have a metatibial gland that produces chemical secretions, likely used in colony communication and during raids ^[5].
• Common Issues: predatory nature requires constant live prey, colonies can decline if not fed enough, colonies may be slow to establish due to polygynous structure and multiple queens to support, escape prevention is important, workers can squeeze through small gaps when motivated, humidity balance is critical, too wet causes mold, too dry causes desiccation, wild-caught colonies may carry parasites that can devastate captive colonies

Housing and Nest Setup

Zasphinctus steinheili nests in soil in the wild, so a naturalistic setup with moist soil works best ^[1]. You can use a Y-tong (AAC) nest or plaster nest with chambers scaled to their medium size of 4-6mm workers. The nest should be kept dark, these ants prefer dim conditions and will be more active in shaded areas of their outworld. Provide a water tube for humidity and mist the outworld occasionally. Since they are predatory, ensure the outworld has enough space for hunting and exploring. Use standard escape prevention like fluon on container edges.

Feeding and Diet

These are obligate predators, they specialize in hunting other ants ^[1]. In captivity, you must provide live prey. Small crickets, fruit flies, and other small insects are accepted, but their preferred food is ant brood and adults from other species. You can occasionally offer small pieces of insect or honey water, but do not rely on these as primary foods. Feed small prey items 2-3 times per week, adjusting based on colony size and consumption. Remove uneaten prey after 24 hours to prevent mold. A well-fed colony will be more active and show more raiding behavior.

Temperature and Seasonal Care

Keep your colony at 22-26°C for optimal activity and development. Australian ants can tolerate warmer conditions but avoid temperatures above 30°C. During winter, provide a mild diapause period, reduce temperature to 15-18°C for 2-3 months. This mimics their natural seasonal cycle in temperate Australia. Do not feed heavily during diapause and reduce disturbance. Return to normal temperatures gradually in spring to trigger increased activity and reproduction.

Behavior and Colony Dynamics

Zasphinctus steinheili shows group foraging behavior, a trait shared with army ants but not as extreme ^[2]. Workers conduct raids on other ant colonies, using chemical signals to confuse and panic defenders. Colonies are polygynous with multiple ergatoid (wingless) queens. This means your colony may have several egg-laying queens simultaneously, which can help colony resilience but also means more resources are needed to support all the queens. The presence of multiple queens does not seem to cause aggression within the colony.

Handling and Temperament

These ants are not aggressive toward keepers and rarely bite. However, they will defend their nest if threatened. Their moderate size and relatively calm demeanor makes them manageable for intermediate keepers. Use standard formicarium setup with proper barrier methods. Workers are active foragers and will explore their outworld thoroughly. They are not known for climbing smooth surfaces aggressively, but escape prevention is still important.

Frequently Asked Questions

References