Probolomyrmex maryatiae

Probolomyrmex maryatiae

Probolomyrmex maryatiae is an extremely tiny ant species from the rainforests of Borneo (Sabah and Sarawak). Workers measure just 0.54-0.58mm in head length, making them among the smallest ants you can keep. They are completely blind (no eyes) and have a distinctive rusty brown coloration. Their petiole (the narrow waist segment) has a unique shape with conspicuous projections underneath. This species is part of the Proceratiinae subfamily, which contains some of the most obscure and rarely kept ants in the hobby. Only five workers have ever been scientifically described, and virtually nothing is known about their biology in the wild or in captivity. They represent a true challenge for advanced antkeepers interested in keeping something most people have never heard of.

Quick Summary

• Difficulty: Expert
• Origin & Habitat: Borneo (Sabah and Sarawak, Malaysia) in Indomalaya region. Found in rainforest and wet forest habitats ^[1]
• Colony Type: Unknown, colony structure has not been documented. Only five workers from a single colony have ever been studied.
• Size & Growth:
  • Queen: Undescribed, no queen has been documented ^[2]
  • Worker: 0.54-0.58mm head length, total body approximately 2-2.5mm ^[2]
  • Colony: Unknown, likely small (under 100 workers) based on genus patterns for rare Proceratiinae
  • Growth: Unknown
  • Development: Unconfirmed, no development data exists for this species (Development timeline is completely unstudied. Related Proceratiinae species suggest 2-4 months at optimal temperature, but this is a rough estimate.)
• Antkeeping:
  • Temperature: Inferred: 24-28°C based on rainforest habitat. Start in this range and observe colony activity.
  • Humidity: Inferred: High humidity (70-85%) based on wet forest habitat. Keep substrate consistently moist but not waterlogged.
  • Diapause: Unknown, no data on overwintering requirements. Borneo has no true winter, so diapause may not be necessary.
  • Nesting: Inferred: Likely nests in soil or rotting wood in nature. Small test tubes or tight acrylic chambers work for their tiny size. Avoid large open spaces.
• Behavior: Behavior is completely unstudied. Based on related Proceratiinae, they are likely predatory and slow-moving. Their tiny size and blindness suggest they hunt micro-prey. Escape prevention must be excellent, they can squeeze through gaps too small for most ants. Sting ability is unknown but likely present (Proceratiinae typically have functional stingers, though too small to affect humans).
• Common Issues: complete lack of biological data means all care is experimental, tiny size makes escape prevention critical, use fine mesh and tight-fitting lids, no confirmed diet, may refuse standard ant foods, slow growth and small colony size may frustrate beginners, virtually impossible to find queens for sale, only wild colony capture possible

Discovery and Taxonomy

Probolomyrmex maryatiae was only described in 2006 by Eguchi, Yoshimura, and Yamane. The holotype and four paratype workers were collected from a single colony in Gunong Rara, Sabah, Malaysia in February 1997. This species is morphologically very similar to three other Probolomyrmex species: P. greavesi, P. salomonis, and P. vieti. The key distinguishing features are in the shape of the petiole (waist) and the subpetiolar process (a projection beneath the waist). In P. maryatiae, the anteroventral projection is relatively thick and not translucent, and the posterodorsal margin of the petiolar node is broadly concave. This is an extremely rare species that has rarely been encountered since its description. ^[2][1]

Appearance and Identification

These are tiny ants, workers have a head length of only 0.54-0.58mm, making them barely visible to the naked eye. They are completely blind, lacking any eyes entirely. Their body is a ferruginous (rusty) brown color. The head has weakly convex sides and a very shallowly concave back. The antennae are relatively short. The mesosoma (middle body section) has an almost straight dorsal outline. The propodeum (the segment behind the mesosoma) has a distinctive translucent lamella on the posterior face. The petiole is roughly as long as it is high, with a gentle anterior slope and concave posterior outline. The subpetiolar process has conspicuous anteroventral and posteroventral projections. The gaster (abdomen) is relatively short and gently narrowed toward the front. ^[2]

Distribution and Habitat

Probolomyrmex maryatiae is known only from Borneo, specifically the Malaysian states of Sabah and Sarawak. This places it in the Indomalaya biogeographic region. The only habitat information available indicates they are found in rainforest and wet forest environments. Borneo has a tropical rainforest climate with high year-round humidity and temperatures. This species appears to be extremely rare or localized, only one colony has ever been scientifically documented. The Probolomyrmex genus as a whole is known from scattered tropical locations across Asia, Africa, and South America, with most species being known from very few specimens. ^[2][1]

Care and Husbandry

WARNING: This species has never been kept in captivity by the antkeeping hobby. All care recommendations are educated guesses based on related Proceratiinae species and general ant biology. You will essentially be a pioneer if you attempt to keep this species. Temperature should be kept in the range of 24-28°C, mimicking the stable warmth of tropical rainforest. Humidity should be high (70-85%), with consistently moist but not flooded substrate. Nest options are limited by their tiny size, small test tubes with cotton plugs or tight acrylic chambers with narrow passages would work. Escape prevention is absolutely critical because of their minute size. They can likely squeeze through gaps that other ants cannot. Feed a diet of tiny live prey appropriate to their size, such as springtails, fruit flies, or other micro-arthropods. Sugar sources may or may not be accepted.

Why Keep This Species?

Probolomyrmex maryatiae is not a species for beginners or even intermediate antkeepers. It is for the specialist collector who wants to keep something truly obscure and challenging. The appeal is in the challenge and the opportunity to learn: you will be discovering things about this species that have never been documented. The tiny size, the complete blindness, and the mystery surrounding their biology make them a fascinating subject for observation. That said, you should have extensive experience with other micro-ant species (like Strumigenys or basic Myrmicinae) before attempting this species. Be prepared for experimental care and be willing to adapt your methods based on what you observe. Success with this species would be a genuine contribution to antkeeping knowledge.

Frequently Asked Questions

References