Stigmatomma silvestrii

Quick Summary

• Difficulty: Hard
• Origin & Habitat: Native to East Asia, Japan, China, Republic of Korea, and Taiwan ^[1]. Found from near Sapporo in Hokkaido south to Iriomote Island in Japan ^[1]. In Taiwan, they inhabit leaf-litter, rotten wood, and soil of well-developed forests and forest edges ^[2]. This is a forest-dwelling species with a cryptic lifestyle, typically nesting in subterranean locations in evergreen broadleaf forests ^[1].
• Colony Type: Monogyne (single-queen) colonies ^[1]. Colonies become mature when worker population exceeds about 10 workers ^[1]. Queens in established colonies obtain nearly all nutrients through larval haemolymph feeding (LHF).
• Size & Growth:
  • Queen: Unknown, queen described but no body length data available. Estimated ~5-6 mm based on queen-worker size ratios in related Amblyoponinae ^[1].
  • Worker: 3.5-4.5 mm ^[1]
  • Colony: Small, likely under 100 workers based on related Amblyoponinae species ^[1]
  • Growth: Slow
  • Development: Unknown, no data available (Development is likely slow due to the semi-claustral founding requirement and the queen's reliance on larval haemolymph. Foundresses must hunt during founding, which may delay first worker emergence.)
• Antkeeping:
  • Temperature: Keep at 18-24°C (room temperature range). Being from temperate East Asia, they can tolerate cooler conditions but prefer steady moderate warmth. Avoid temperatures above 28°C, no experimental data on optimal range ^[1].
  • Humidity: High humidity is required, think damp forest floor conditions. Keep the nest substrate consistently moist but not waterlogged. These subterranean ants need stable moisture ^[2].
  • Diapause: Likely requires a winter rest period (diapause) given their temperate to subtropical distribution. Reduce temperature to around 10-15°C for 2-3 months during winter (roughly November-February in the Northern Hemisphere) ^[1].
  • Nesting: Prefers naturalistic setups with moist substrate. A soil-based formicarium or test tube setup connected to damp soil works well. They are subterranean nesters found in leaf-litter and rotting wood in the wild ^[2]. Provide a dark, humid nesting area.
• Behavior: Docile and secretive, these ants avoid confrontation. Workers have a sting (subfamily Amblyoponinae) but rarely use it on humans. They are specialized centipede hunters that forage solitarily ^[3]. Their small size (3.5-4.5 mm) makes escape prevention essential. Queens are highly dependent on larvae for nutrition in established colonies, creating unique colony dynamics. Foundresses must hunt to survive, making early colony establishment challenging.
• Common Issues: semi-claustral founding means foundresses must have access to live prey, colonies can fail if queens cannot hunt, queen dependency on larval haemolymph in established colonies may cause stress if the colony is small, specialized centipede diet makes feeding challenging, they may refuse other prey, small size requires good escape prevention despite their docile nature, high humidity requirements can lead to mold issues if ventilation is poor

Housing and Nest Setup

Stigmatomma silvestrii needs a humid, naturalistic setup that mimics their forest floor habitat. These subterranean ants prefer dark, damp conditions and do best in a soil-based formicarium or a test tube setup connected to a foraging area with moist substrate ^[2]. Keep the nesting area dark and humid, cover the nest with a dark cloth or use a nest box with limited light. For the outworld, provide a shallow container with damp soil or coco fiber that holds moisture well. Given their small size (3.5-4.5 mm), secure all connections and barriers, they can escape through surprisingly small gaps. A layer of fluon on the rim of the foraging container helps prevent escapes.

Feeding and Diet

This is the most challenging part of keeping S. silvestrii. In the wild, they are specialized centipede predators, mainly hunting geophilid centipedes ^[4][5]. Their natural prey includes mecistocephalid centipedes, but they consistently fail to hunt Strigamia centipedes in laboratory tests ^[6][7]. You will need to culture or source small live centipedes regularly. Some keepers report limited success with small millipedes, but centipedes are their preferred and natural prey. Foundresses absolutely require access to live prey during founding, they cannot survive on stored fat alone. In established colonies, queens get most nutrients from larval haemolymph, but workers still need prey for the colony to function ^[1]. Offer small live centipedes or other appropriate prey 2-3 times per week. Cannibalism of reproductive eggs has also been reported in this species ^[8].

Temperature and Seasonal Care

Keep your colony at room temperature, ideally between 18-24°C. Being from temperate East Asia (Japan, Korea, China), they can tolerate cooler conditions but prefer steady moderate warmth. Avoid temperatures above 28°C, this may stress the colony. During winter, given their range extends to northern Japan (Hokkaido), they likely benefit from a diapause period. Reduce temperatures to around 10-15°C for 2-3 months during winter (roughly November-February in the Northern Hemisphere) to mimic their natural seasonal cycle. If the colony becomes very sluggish during diapause, that is normal ^[1].

Understanding Larval Haemolymph Feeding

One of the most unusual aspects of S. silvestrii biology is larval haemolymph feeding (LHF). In established colonies, queens obtain nutrients almost exclusively by wounding mature (5th instar) larvae and drinking their haemolymph ^[1]. The queen uses her sharp mandibles to pierce the larval body between abdominal segments, then laps up the haemolymph that flows out. The larvae survive these wounds, they develop scars but continue developing and can pupate successfully ^[1]. Queens perform LHF at intervals of approximately 5-10 hours depending on temperature ^[1]. In your colony, you may observe queens actively manipulating larvae and may notice scarred larvae, this is normal and essential for queen nutrition in mature colonies. LHF is a queen-only behavior, workers and uninseminated females rarely perform it ^[1].

Colony Founding

Starting a colony of S. silvestrii is more challenging than many common ant species because they are semi-claustral. Unlike claustral queens that seal themselves in and survive on body fat, foundresses must leave the nest to hunt centipedes to feed themselves and their first brood ^[1]. This means you cannot simply keep a founding queen in a sealed test tube, she needs access to a hunting area with live prey. Provide a founding setup with a small, humid chamber connected to a tiny foraging area where you can offer small live centipedes. Foundresses spend more time hunting and less time on LHF compared to queens in established colonies ^[1]. The first workers (nanitics) will be small but should eventually help with hunting. Colony founding success is low due to the queen's need to hunt while also caring for brood.

Behavior and Temperament

S. silvestrii is a docile, non-aggressive species that prefers to avoid confrontation. Workers are small and solitary foragers, they hunt centipedes alone rather than in groups ^[3]. As an Amblyoponinae ant, they have a functional sting and can deliver a painful sting if provoked, but they are not aggressive toward humans and rarely sting unless handled roughly. Given their cryptic lifestyle, you may not see much activity outside the nest, especially during daylight hours, they are primarily nocturnal or crepuscular. Colony dynamics are unique, established queens are largely dependent on larval haemolymph and ignore available prey in the brood chamber ^[1]. This means the colony must maintain a healthy larval population to support the queen. Keep in mind their small size (3.5-4.5 mm) when designing enclosures, they can escape through tiny gaps.

Frequently Asked Questions

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References