Lachnomyrmex haskinsi

Lachnomyrmex haskinsi

Lachnomyrmex haskinsi is a tiny Neotropical ant native to the wet forests of Costa Rica and Panama, found at elevations between 200-800 meters. Workers measure just 2.65-2.94mm in total length, with a distinctive reddish-ferruginous to brown body covered in fine, wavy rugae (wrinkles) and featuring an unusually elevated, subtriangular petiolar node. The postpetiole has a raised bump in the center and sports about six long hairs, while the first segment of the abdomen is notably bare of long hairs, a key identification feature. These ants belong to the Stenammini tribe and form relatively small colonies with a single queen. They nest in the ground, among rotting leaves, and inside fallen logs, with workers foraging alone through leaf litter without recruiting nestmates.

One of the most fascinating aspects of L. haskinsi is an unusual observation by Dr. John Longino, who found workers and a larva scattered throughout debris inside a Brachymyrmex nest beneath rotten wood. While inquilinism (a form of social parasitism where one species lives in the nest of another) was suspected, it was never confirmed. This makes them an intriguing species for keepers interested in observing potential social interactions.

Quick Summary

• Difficulty: Medium
• Origin & Habitat: Costa Rica and Panama,200-800m elevation wet forests ^[1][2]. Found in leaf litter of submontane wet forests, typically nesting in ground, among rotten leaves, and inside fallen logs ^[3].
• Colony Type: Apparently monogynic, colonies have a single queen ^[3]. Small colony size with workers foraging individually.
  • Colony: Monogyne
  • Founding: Claustral
• Size & Growth:
  • Queen: Not directly measured in available literature, but gyne (queen) described by Feitosa & Brandão 2008 with eyes having about 12 facets ^[1]. Estimated 4-5mm based on worker size ratio.
  • Worker: 2.65-2.94mm total length ^[2][1]. Head length 0.60-0.65mm, head width 0.55-0.63mm.
  • Colony: Relatively small colonies ^[3]. Estimated 50-200 workers based on similar litter ants.
  • Growth: Moderate, development timeline unconfirmed but expected 6-10 weeks from egg to worker based on related Stenammini species.
  • Development: Estimated 6-10 weeks at optimal temperature (around 24-26°C) based on genus patterns for small Myrmicinae in tropical wet forests. Not directly studied for this species. (Timeline is estimated from related species, actual development time may vary. Nanitics (first workers) will be smaller than normal workers.)
• Antkeeping:
  • Temperature: Keep at 24-26°C. As a wet forest species from Costa Rica and Panama, they prefer warm, stable conditions. Avoid temperatures below 20°C or above 30°C. A heating cable on one side of the nest can create a gentle gradient if room temperature is insufficient.
  • Humidity: High humidity is essential, these ants come from wet tropical forests. Keep nest substrate consistently moist but not waterlogged. The substrate should feel damp to the touch with condensation visible on nest walls. Provide a water tube for drinking water.
  • Diapause: No, as a tropical species from wet forests, they do not require hibernation. Maintain consistent temperatures year-round.
  • Nesting: Y-tong (acrylic) nests or plaster nests work well for these tiny ants. The nest should have small chambers and narrow passages scaled to their tiny size. Naturalistic setups with rotting wood pieces and moist leaf litter can also work. Avoid tall, open spaces.
• Behavior: Workers are solitary foragers that search for food alone through leaf litter rather than recruiting nestmates or forming pheromone trails ^[3]. They are not aggressive and pose no sting threat to humans due to their tiny size. Escape risk is moderate, while small at ~3mm, they are not as prone to escaping as extremely minute species. Still, use standard barrier methods. They are primarily ground-dwelling and rarely climb. Queens seal themselves in during founding (likely claustral based on genus patterns).
• Common Issues: high humidity is critical, dry conditions will kill colonies quickly since they're adapted to wet forest habitats, small colony size means slow growth, beginners may lose patience and overfeed, leading to mold problems, their cryptic lifestyle (foraging alone in leaf litter) means you may not see much activity, this is normal, not a problem, possible inquilinism relationship with Brachymyrmex means wild-caught colonies could have social parasite complications, test tube setups require careful water management, too much water causes flooding, too little causes desiccation

Housing and Nest Setup

Lachnomyrmex haskinsi is a tiny ant that needs appropriately scaled housing. Y-tong (acrylic) nests or plaster nests work well because they hold humidity well and provide the small chambers these ants prefer. The chambers should be small and the passages narrow, avoid large, open spaces that can stress these small ants. A naturalistic setup can also work: use a container filled with moist substrate (a mix of soil and rotting wood pieces) with pieces of decaying wood or leaves on top for cover. This mimics their natural habitat in forest leaf litter. Whatever setup you choose, ensure excellent escape prevention, while not the smallest ants, they can still squeeze through small gaps. Use tight-fitting lids and consider barrier methods like fluon on container edges. ^[3][2]

Feeding and Diet

As a member of the Stenammini tribe, L. haskinsi is likely a predator and scavenger. Feed them small protein sources like fruit flies, pinhead crickets, small mealworms, and other tiny insects. They may also accept sugar water or honey as an energy source, though this is not confirmed. Given their tiny size and solitary foraging behavior, food items should be appropriately small. Offer protein roughly twice weekly and sugar sources constantly if accepted. Remove uneaten prey after 24-48 hours to prevent mold. Since workers forage alone in leaf litter, they may prefer hunting live prey, try offering small live insects and observe if they accept them. ^[3]

Temperature and Humidity

These ants come from the wet forests of Costa Rica and Panama, so they need warm, humid conditions. Keep temperatures in the range of 24-26°C, avoiding drops below 20°C or spikes above 30°C. A heating cable on one side of the nest can create a temperature gradient if needed, place it on top of the nest material, not underneath, to avoid evaporating moisture too quickly. Humidity is critical: maintain consistently moist substrate without waterlogging. The nest should show condensation on walls, and the substrate should feel damp to the touch. Mist occasionally but rely more on water tubes or reservoirs to maintain stable humidity. Poor humidity will kill colonies quickly. ^[1][2]

Colony Dynamics and Behavior

L. haskinsi forms relatively small colonies with a single queen (monogynic) ^[3]. Workers are solitary foragers that search for food alone rather than recruiting nestmates, they do not form pheromone trails ^[3]. This means you'll often see just one or two workers active at a time, which is normal for this species. The colony will grow slowly, so patience is key. Queens are likely claustral, they seal themselves in a chamber and raise the first brood alone without foraging, living off stored fat reserves until the first workers emerge. This is typical for small Myrmicinae. The unusual observation of workers in a Brachymyrmex nest suggests possible inquilinism (temporary social parasitism), but this was never confirmed. For now, treat them as independent colony founders.

Growth and Development

Workers measure only 2.65-2.94mm total length, making them among the smaller ant species kept in captivity ^[2][1]. The queen is slightly larger with eyes having about 12 facets (workers have only 5-7) ^[1]. Colony growth is moderate but slow, you can expect 6-10 weeks from egg to first worker at optimal temperature, though this is estimated from related species rather than directly documented. First workers (nanitics) will be smaller than normal workers. Colonies remain relatively small compared to many Myrmicinae, typically reaching perhaps 50-200 workers at maturity. This species is not a fast-growing one, so keepers should be patient and avoid overfeeding which causes mold issues in small colonies.

Frequently Asked Questions

References