Oxyepoecus striatus

Quick Summary

• Difficulty: Expert
• Origin & Habitat: Río Verde, Presidente Hayes, Paraguay (S 23.22,W 59.20) in the Neotropical region, with records in northern Argentina ^[3]. Found in areas with mean annual rainfall of 887mm and temperature of 23°C ^[1].
• Colony Type: Unknown, only the worker caste has been described. Queen and male are unknown. Colony structure has not been documented.
• Size & Growth:
  • Queen: Unknown, queen has not been described ^[3]
  • Worker: 1.6-1.7mm total length (TL) ^[1][2]
  • Colony: Unknown, only a few workers have ever been collected ^[1]
  • Growth: Unknown
  • Development: Unknown, no development data exists for this species. Based on related tiny Myrmicinae, estimated 4-8 weeks at optimal temperature. (No direct observations of colony development exist. Estimate based on genus patterns for small tropical Myrmicinae.)
• Antkeeping:
  • Temperature: Keep around 22-26°C, based on mean annual temperature of 23°C at type locality ^[1]. A gentle temperature gradient allows workers to regulate exposure.
  • Humidity: Maintain moderate humidity, similar to their subtropical habitat with 887mm annual rainfall ^[1]. Keep nest substrate consistently moist but not waterlogged.
  • Diapause: Unknown, no specific data. Based on subtropical climate, a mild seasonal slowdown may occur, but hibernation is unconfirmed.
  • Nesting: Ground-dwelling species collected in pitfall traps ^[1]. Use test tube setups or Y-tong (AAC) nests with moist substrate. Ensure chambers are scaled for tiny workers.
• Behavior: Workers are small with limited visual orientation ^[1]. Escape prevention is critical due to their tiny size. Use fine mesh barriers and tight-fitting lids.
• Common Issues: escape prevention is critical, at 1.6mm, they can squeeze through standard mesh barriers ^[1], no captive husbandry information exists, this is an extremely rare species in collections, colony size is unknown, wild colonies may be very small, queen and male are unknown, founding behavior is unconfirmed, slow growth is likely given their tiny size and subtropical origin

Appearance and Identification

Oxyepoecus striatus is one of the smallest ants you can keep, with workers measuring just 1.6-1.7mm in total length ^[1][2]. They are a uniform medium reddish-brown color throughout. The most distinctive feature is the striated sculpturing on their mesosoma, the pronotum and mesonotum have longitudinal parallel lines, while the dorsopropodeum has fine transverse lines ^[1]. This is how the species got its name ('striatus' means striped). They have small but well-defined sharp teeth on the clypeus, and their eyes are very small with only about 18 ommatidia ^[1]. The scapes are relatively short, not reaching the back of the head. Workers have abundant erect hairs on most body surfaces, giving them a slightly fuzzy appearance under magnification.

Natural History and Distribution

This species is known only from the type locality of Río Verde in central Paraguay, with records also in northern Argentina ^[3]. The area has a mean annual temperature of 23°C and receives about 887mm of rainfall annually, a subtropical climate with distinct wet and dry seasons ^[1]. Specimens have been collected in pitfall traps, which are containers buried in the ground to catch walking insects. This indicates they are ground-dwelling ants that forage on the soil surface or in leaf litter. The species was described in 2011 and remains poorly known, only a handful of workers have ever been collected. The queen and male castes remain undescribed, and nothing is known about their colony structure, nuptial flights, or reproductive behavior.

Housing and Nest Setup

Given their tiny size and ground-dwelling habits, use appropriately scaled housing. A test tube setup works well for founding colonies, use a small test tube with a cotton ball providing moisture. For established colonies, a Y-tong (AAC) nest with narrow chambers or a small plaster/soil nest maintains appropriate humidity. The key requirement is moisture, their native habitat receives nearly 900mm of rainfall annually, so keep the nest substrate consistently damp but not flooded. Because workers are only 1.6mm long, escape prevention must be excellent. Standard mesh will not contain them. Use fine mesh (0.5mm or smaller) or apply fluon to barrier edges. Check for gaps around lid edges and any tubing connections. ^[1]

Temperature and Seasonal Care

Maintain temperatures around 22-26°C to match their subtropical origin in central Paraguay ^[1]. A slight temperature gradient allows ants to regulate their body temperature. During the Southern Hemisphere winter (roughly June to August), reduce temperatures to around 18-20°C to simulate seasonal cooling. This species likely experiences reduced activity during cooler months rather than a true hibernation. Monitor colony behavior, if workers become less active and cluster together, temperatures may be slightly too cold. Avoid temperature extremes, as tiny ants desiccate quickly and have limited thermal mass.

Feeding and Nutrition

No specific feeding observations exist for this species in captivity. Based on related members of the tribe Solenopsidini, they likely accept sugar sources and small protein prey. Offer a small drop of sugar water or honey diluted with water and small live prey such as fruit flies, springtails, or other tiny arthropods. Given their minute size, standard ant feeders are too large. Use very small food portions, a drop of sugar water the size of a pinhead is sufficient. Remove uneaten prey after 24-48 hours to prevent mold. Feed every 2-3 days, adjusting based on colony size and consumption.

Challenges and Considerations

Oxyepoecus striatus is an extremely rare species in the antkeeping hobby, with virtually no captive husbandry information available. This makes it an expert-level species, you will essentially be pioneering captive husbandry for this ant. Key challenges include: their tiny size requires specialized housing and excellent escape prevention, colony size in the wild is unknown, so realistic growth expectations are unclear, the queen has never been described, so founding behavior is unconfirmed, and no established care protocols exist. If you obtain a colony, detailed record-keeping would be valuable for building husbandry knowledge. This species is best suited for experienced antkeepers who enjoy the challenge of working with poorly documented species. ^[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