Tetramorium repletum

Tetramorium repletum

Tetramorium repletum is a small ant species native to Yunnan Province, China. Workers measure approximately 2.8mm in total body length, with a reddish-brown coloration where the head and mesosoma are slightly lighter than the gaster, while the legs are yellow-brown ^[1]. This species was formally described in 1988 by Wang, Xiao, and Wu, and remains poorly studied in both its native habitat and in captivity ^[1].

As a Tetramorium species, these ants likely share typical genus behaviors: they are ground-nesting ants that probably prefer moist, shaded microhabitats in their natural Yunnan environment. The limited scientific data available means much of what we know comes from general Tetramorium genus patterns rather than species-specific research.

Quick Summary

• Difficulty: Medium
• Origin & Habitat: Yunnan Province, China (Palaearctic Region). This region features a tropical to subtropical climate with high humidity and dense vegetation.
• Colony Type: Presumed single-queen (monogyne) colonies based on typical Tetramorium genus structure.
  • Colony: Monogyne
  • Founding: Claustral
• Size & Growth:
  • Queen: Undocumented, estimated 5-7mm based on genus patterns
  • Worker: 2.8mm ^[1]
  • Colony: Unknown, likely several hundred workers based on typical Tetramorium colony sizes
  • Growth: Moderate
  • Development: Estimated 6-10 weeks at optimal temperature based on related Tetramorium species (Development time is estimated from genus-level data since species-specific research is unavailable)
• Antkeeping:
  • Temperature: Keep at 22-26°C, aim for warm, stable conditions. Yunnan has mild annual temperatures, so avoid extreme heat.
  • Humidity: High humidity preferred, keep nest substrate consistently moist but not waterlogged. These ants likely evolved in damp forest floor environments.
  • Diapause: Likely required, temperate Yunnan experiences cool winters. Provide 2-3 months of reduced temperature (10-15°C) during winter.
  • Nesting: Ground-nesting species. Y-tong (AAC) nests or naturalistic setups with moist substrate work well. Provide deep soil or sand for potential burrowing.
• Behavior: Presumed docile temperament typical of most Tetramorium species. Workers are small at 2.8mm, so escape prevention is important despite their non-aggressive nature. They likely forage for small insects and tend aphids for honeydew.
• Common Issues: limited species-specific research means care recommendations are partly inferred from genus patterns, high humidity requirements can lead to mold problems if ventilation is poor, small worker size creates escape risk through tiny gaps, winter diapause is necessary but timing and duration may vary, wild-caught colonies may have parasites or diseases not yet documented

Appearance and Identification

Tetramorium repletum workers are small ants measuring approximately 2.8mm in total body length. The body coloration is reddish-brown, with the gaster being slightly darker than the head and mesosoma. The legs are yellow-brown, helping distinguish this species from darker Tetramorium species. Workers have 12-segmented antennae with the terminal 3 segments forming a club. The propodeum (the section behind the mesosoma) features long, sharp spines that curve slightly upward. The head is nearly square-shaped with a straight occipital margin. The first node (the first segment of the waist) is nearly square when viewed from the side, while the second node is nearly spherical when viewed from above ^[1].

Distribution and Natural Habitat

This species is known only from Yunnan Province in southern China, which lies in the Palaearctic Region. Yunnan features a diverse range of habitats from tropical forests to mountainous regions, all characterized by high humidity. The specific microhabitat preferences of T. repletum are not documented, but most Tetramorium species are ground-nesting ants that prefer moist, shaded areas with access to soil for burrowing. They are often found in forest edges, under stones, or in rotting wood on the forest floor.

Temperature and Heating

Based on Yunnan's climate, these ants prefer warm but not hot conditions. Aim for temperatures between 22-26°C in the nest area. You can achieve this using a heating cable placed on top of the nest (never underneath, as it causes excessive drying) or a heat mat on one side of the enclosure to create a temperature gradient. This allows workers to regulate their body temperature by moving between warmer and cooler areas. Avoid temperatures above 30°C, as this can stress the colony. Room temperature within this range is acceptable if your home stays consistently warm.

Humidity and Moisture

Tetramorium repletum requires high humidity, reflecting their origin in the humid Yunnan region. Keep the nest substrate consistently moist, it should feel damp to the touch but not have standing water. A moisture gradient works well, with some areas slightly wetter than others, allowing ants to choose their preferred conditions. For test tube setups, ensure the water reservoir is adequate but not prone to flooding. For Y-tong or naturalistic nests, mist the substrate periodically and monitor for drying. Good ventilation is essential to prevent mold while maintaining humidity.

Feeding and Diet

Like most Tetramorium species, T. repletum is likely omnivorous, feeding on small insects, seeds, and honeydew from aphids. In captivity, offer a varied diet including small live prey such as fruit flies, pinhead crickets, or mealworm pieces. Sugar sources like diluted honey or sugar water are typically accepted. Feed protein sources 2-3 times per week and keep sugar water available at all times. Remove uneaten prey after 24-48 hours to prevent mold. Since workers are small (2.8mm), prey items should be appropriately sized, very small insects or crushed fragments work best.

Colony Founding

The founding behavior of Tetramorium repletum has not been directly documented. Based on typical Tetramorium genus patterns, the queen likely performs claustral founding, she seals herself in a small chamber, uses her stored fat reserves to survive, and raises the first brood without leaving to forage. The first workers (nanitics) are typically smaller than mature workers. After the first workers emerge, the colony expands gradually. Founding colonies should be kept in a quiet, dark location with stable temperature and humidity.

Diapause and Winter Care

Since Yunnan experiences cool winters, Tetramorium repletum likely requires a diapause period. From late autumn to early spring (approximately November through February in the Northern Hemisphere), reduce temperatures to 10-15°C. This simulates winter and helps the colony enter a resting state. During diapause, reduce feeding to once every 2-3 weeks and keep the nest slightly drier but not completely dry. Do not feed during the coldest months. Return to normal temperatures gradually in spring to trigger renewed activity and brood development.

Frequently Asked Questions

References