Crematogaster masukoi

Quick Summary

• Difficulty: Expert
• Origin & Habitat: Borneo (Malaysia: Sabah and Indonesia: Kalimantan). This species inhabits developed forests and nests directly in soil, indicating it lives underground in the dark. The reduced eyes and pale yellow-brown coloration are classic adaptations to subterranean life. ^[1]
• Colony Type: Colony structure is unconfirmed. Only workers have been described, queens are unknown. Based on typical Crematogaster patterns, they may form multi-queen colonies, but this has not been documented for this specific species.
• Size & Growth:
  • Queen: Unknown, queens have not been described or measured.
  • Worker: ~3-4mm, inferred from Crematogaster genus size range ^[1].
  • Colony: Unknown, no colony size data exists for this species.
  • Growth: Unknown, no development data exists.
  • Development: Unconfirmed, no direct observations of development exist for this species. (This is a tropical species, development may be faster than temperate species but specific timing is unknown.)
• Antkeeping:
  • Temperature: Being from tropical Borneo, keep them warm. A gentle heat gradient allowing temperatures in the low-to-mid 20s°C range is appropriate. Room temperature is likely acceptable as a starting point.
  • Humidity: As a subterranean soil-nesting species from rainforest Borneo, they need high humidity. Keep the nest substrate consistently moist but not waterlogged.
  • Diapause: Unknown, being a tropical species from Borneo near the equator, they likely do not require a diapause period. However, slight seasonal slowdowns may occur during drier periods in their native habitat.
  • Nesting: As a soil-nesting subterranean species, they do best in setups that provide dark, humid conditions. A Y-tong (AAC) nest or plaster nest with moist substrate works well. Provide deep, narrow chambers scaled to their tiny size. Avoid bright lighting as they likely prefer darkness.
• Behavior: This species is poorly documented in captivity, but being subterranean with reduced eyes, they are likely secretive and not aggressive foragers. Workers are tiny and will likely show typical Crematogaster behavior, they may raise their abdomen when threatened as a defensive posture. Escape prevention is critical due to their very small size. They probably prefer to forage in darkness and may not venture into bright outworlds.
• Common Issues: tiny size means escapes are likely without fine mesh barriers and careful sealing., no captive breeding data exists, wild colonies are the only source., subterranean nature means they may be difficult to observe and may stress in bright conditions., high humidity requirements can lead to mold if ventilation is poor., unknown colony structure makes it unclear how many queens to keep together.

Nest Preferences and Housing

Crematogaster masukoi is a subterranean species that nests in soil in developed forests. In captivity, provide a nest that maintains darkness and high humidity. A Y-tong (AAC) nest or plaster formicarium with moist substrate works well. The chambers should be small and narrow, scaled to their tiny worker size. Avoid bright lighting near the nest, they have highly reduced eyes and prefer dark conditions. Keep the nest substrate consistently moist but not flooded. A water reservoir connected to the nest helps maintain humidity. Given their subterranean nature, they may not use a traditional outworld much and may prefer to stay hidden in the nest chambers. ^[1]

Feeding and Diet

No captive feeding observations exist for this species. As a Crematogaster, they likely have a typical diet of honeydew from aphids and small insects. In captivity, offer sugar water or honey as an energy source, along with small protein sources like fruit flies, pinhead crickets, or other tiny arthropods. Their tiny size means prey items must be small. Being subterranean, they may not be aggressive foragers and might prefer feeding within the nest rather than in an outworld. Start with sugar sources and observe acceptance before offering protein.

Temperature and Seasonal Care

This species comes from tropical Borneo where temperatures are warm year-round. Keep the nest around 24-28°C for optimal activity. A heating cable on one side of the nest creates a temperature gradient, allowing ants to choose their preferred zone. Room temperature in most homes (22-25°C) may be acceptable as a starting point. Monitor colony behavior, if workers become sluggish, slightly increase temperature. Being from near the equator, they likely do not require a winter diapause. However, slight seasonal changes in activity may occur during natural dry periods in their native habitat. ^[1]

Defense Mechanism

Like other Myrmicinae ants, Crematogaster masukoi has a modified, flattened stinger used to wipe or smear venom onto enemies rather than piercing flesh. This smear defense is characteristic of the Crematogastrini tribe. When threatened, workers may also raise their abdomen in a defensive posture, though their tiny size means any sting would be negligible to humans.

Understanding Their Unique Biology

Crematogaster masukoi is one of the more unusual Crematogaster species due to its highly reduced eyes (only about 6 ommatidia) and pale, depigmented yellow-brown coloration. These are classic adaptations to subterranean life, living in darkness where eyes are unnecessary and pigmentation provides no camouflage benefit. The species was only described in 2010 and is known only from workers, queens have never been discovered or described. This makes it one of the rarest species in the antkeeping hobby. The genus Crematogaster is known for their distinctive behavior of raising their abdomen when threatened, and this species likely shares that trait despite its tiny size. ^[1][2]

Acquiring This Species

Crematogaster masukoi is extremely rare in the antkeeping hobby. It was only described in 2010 and has a limited distribution in Borneo. Unlike common Crematogaster species like Crematogaster scutellaris or Crematogaster ashbyi, this species is not commercially available and would require field collection in its native range (with proper permits). Most antkeepers will never encounter this species for sale. If you do obtain wild-caught specimens, be extremely careful with escape prevention due to their tiny size, they can squeeze through gaps invisible to the naked eye. Quarantine and observe new colonies carefully, as little is known about their captive requirements. ^[1]

Frequently Asked Questions

Report an Issue

The current care sheet is based fully on literature. See inconsistencies, or something that's incorrect? Please report here, it will be resolved after review from an admin. Contributing to the blogs tab also helps providing information, to make us be able to further improve the caresheets. Thank you for your support!

References