Scientific illustration of Adelomyrmex grandis ant - showing key identification features including head, thorax, and gaster.

Adelomyrmex grandis

Non-Parasitic Queen No Gamergate
Sci. Name
Adelomyrmex grandis
Tribe
Solenopsidini
Subfamily
Myrmicinae
Author
Fernández, 2003
Distribution
Found in 0 countries

Introduction

Adelomyrmex grandis workers are the largest known species in their genus, reaching about 4.2 mm in total body length . They are uniformly brown to dark brown with distinctive longitudinal ridges running along the head and mesosoma, and they possess six teeth on their mandibles that decrease in size from the apical teeth . This species comes from the tropical foothills of southwestern Colombia, specifically the Nariño department near Barbacoas at 520 meters elevation . Only workers have ever been documented. Queens and males remain completely unknown to science, making captive breeding impossible since no one has ever documented how colonies start or what a queen looks like .

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Status by country, from Kass et al. 2022 & Wong et al. 2023

Native Invasive Introduced (indoor) Intercepted Unknown
Data Sources
Year Range 2000 - 2026

Quick Summary

  • Difficulty: Expert
  • Origin & Habitat: Southwestern Colombia, western foothills of the Cordillera Occidental in Nariño department, around 520m elevation [1][3][2]. Tropical foothill forest.
  • Colony Type: Unknown, only worker specimens have ever been collected [5][4]
  • Size & Growth:
    • Queen: Unknown, undescribed [4]
    • Worker: 4.2 mm total length [1][4]
    • Colony: Unknown
    • Growth: Unknown
    • Development: Unknown (Development timeline completely undocumented)
  • Antkeeping:
    • Temperature: Unknown, based on tropical Colombian location at 520m, start with stable 24-26°C and observe colony response
    • Humidity: Unknown, likely requires high humidity given tropical origin, keep substrate moist but not waterlogged
    • Diapause: Unknown, likely not required for tropical species
    • Nesting: Unknown
  • Behavior: Unknown, no behavioral studies exist. Workers possess six mandibular teeth and relatively large eyes with more than 30 facets [1]. As a member of the Myrmicinae subfamily, they likely possess a stinger for defense.
  • Common Issues: complete lack of biological data makes captive care experimental and high-risk, queen and male castes undescribed, impossible to identify founding queens or establish new colonies, only known from a handful of worker specimens collected in 1994, virtually unobtainable in the pet trade, unknown founding behavior means standard setups may be inappropriate

Identification and Geographic Range

Workers measure about 4.2 mm from head to abdomen tip, making them the giants of the Adelomyrmex genus [1][2]. The body is uniformly dark brown, lacking the two-toned coloration seen in their relative Adelomyrmex vaderi [3]. Key features include six teeth on the mandibles that decrease in size from front to back, and relatively large eyes containing more than 30 individual facets [1]. The head and mesosoma show distinct lengthwise ridges (striations), while the waist segments have rough, irregular sculpturing [1]. This species has only been found in one location: the western slopes of the Cordillera Occidental in Colombia's Nariño department, near Barbacoas at 520 meters elevation [1][3][2].

The Mystery of Missing Castes

Science has never documented a queen or male of this species [4]. Every specimen in collections is a worker. This creates a major problem for antkeepers: we do not know how colonies start, how many queens they have, or what the reproductive individuals look like. Without this basic information, attempting to keep this species would be pure guesswork. You could not identify a founding queen if you found one, nor would you know if she needs to forage during founding or seal herself in a chamber.

Habitat and Climate Inferences

The type locality sits at 520 meters in tropical foothills of southwestern Colombia [1]. This elevation suggests warm, stable temperatures year-round with high humidity. While exact requirements remain unstudied, you should avoid cool temperatures or winter hibernation periods. Start with temperatures around 24-26°C and high humidity, but recognize these are educated guesses based on geography rather than confirmed biological data.

Why This Species Is Not Recommended for Captivity

Adelomyrmex grandis represents the extreme end of difficulty in ant keeping. Beyond the lack of biological data, the species is exceptionally rare. All known specimens come from a single collection event in 1994 [1][3]. No one has attempted captive rearing, so even basic questions about diet, nesting preferences, and colony growth remain unanswered. For practical purposes, this species exists only in scientific collections and is not a viable candidate for home ant farms until researchers document its basic biology.

Frequently Asked Questions

Can I keep Adelomyrmex grandis in a test tube?

Unknown. Since queens have never been described, we do not know if this species founds colonies in sealed chambers or if queens need to forage during founding. Any founding attempt would be experimental.

How long until first workers for Adelomyrmex grandis?

Unknown. Development time from egg to worker has never been documented for this species.

What do Adelomyrmex grandis eat?

Unknown. Their natural diet has not been studied. Based on related myrmicine ants, they may accept small insects and sweet liquids, but this is speculation.

Do Adelomyrmex grandis need hibernation?

Unknown, but likely not. They come from tropical Colombia where temperatures remain warm year-round [1].

How big do Adelomyrmex grandis colonies get?

Unknown. Colony size has never been documented.

Are Adelomyrmex grandis good for beginners?

No. This is an expert-level species due to complete lack of care information and the fact that only workers are known to science.

Do Adelomyrmex grandis sting?

They likely possess a stinger typical for the Myrmicinae subfamily, but its effectiveness against humans is unstudied.

Where do Adelomyrmex grandis come from?

Southwestern Colombia, specifically the Nariño department near Barbacoas at 520m elevation [1][3].

Can I keep multiple Adelomyrmex grandis queens together?

Unknown. Whether this species accepts multiple queens has never been observed.

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References

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This caresheet is licensed under CC BY-SA 4.0 .