Lioponera cohici

Lioponera cohici

Lioponera cohici is a medium-sized, shining black ant belonging to the subfamily Dorylinae. Originally described as Lioponera cohici by Wilson in 1957,this species is endemic to New Caledonia, an island in the southwestern Pacific. Workers measure around 1mm in head width and are characterized by their distinctly rounded dorsal propodeal corners, which form an angle of more than 110° when viewed from the side, a key identification feature that separates them from related Australian species in the turneri group which have angles of 90° or less. The entire body is deep blackish brown to jet black, with dark reddish-brown mandibles and gastric apex. This species is a specialized predator that raids colonies of other ants, particularly Pheidole, and forages during the day in characteristic file formation over the ground surface ^[1].

Quick Summary

• Difficulty: Expert
• Origin & Habitat: New Caledonia, subtropical evergreen forest in the hills extending from the south bank of the Canala River near Ciu Falls, at elevations of 300-500 meters. Nests are found under rocks in densely shaded forest areas or in open soil along forest trails^[2].
• Colony Type: Colony structure is not fully documented. Related species in the Cerapachys sulcinodis complex show queen-worker dimorphism with colony sizes around 100 workers. The single documented colony had approximately 80-100 workers with 40 pupae,30-40 larvae, and 30 eggs.
• Size & Growth:
  • Queen: Unknown, queen morphology has not been described for this species
  • Worker: 0.88-1.01mm head width
  • Colony: Approximately 80-100 workers based on field collections
  • Growth: Unknown, estimated as moderate based on related species
  • Development: Unknown for this species. Related non-army ant dorylines suggest 6-10 weeks at optimal temperature. (Development timeline has not been directly studied. Estimates based on related Dorylinae species.)
• Antkeeping:
  • Temperature: Inferred as warm-temperate to subtropical based on native habitat in New Caledonia. Aim for 22-26°C and observe colony activity. Provide a gentle temperature gradient.
  • Humidity: Requires moderate to high humidity, native habitat is damp subtropical forest. Keep nest substrate consistently moist but not waterlogged. Provide a humidity gradient with a moist chamber and slightly drier areas.
  • Diapause: Unknown, no documented hibernation period. New Caledonia has a mild subtropical climate with no harsh winter, so diapause may not be required. Monitor colony activity and adjust seasonal care accordingly.
  • Nesting: In captivity, provide a naturalistic setup with soil or a Y-tong/plaster nest with narrow chambers. In the wild, they nest under rocks in shaded forest soil with galleries leading to chambers against buried rocks. Use substrate that holds moisture well and provides dark, humid chambers.
• Behavior: This is a predatory ant species that actively raids colonies of Pheidole ants. Workers forage during the day, always moving in file formation over the ground surface. They are also found in rotting logs. Males are winged and attempt to fly when the nest is disturbed. They are not escape artists in the traditional sense but their small size means standard escape prevention measures should be used. Their predatory nature means they will require live prey in captivity.
• Common Issues: predatory feeding requirements make them difficult to feed, need constant supply of live prey, colony size remains relatively small, limiting visual impact compared to larger species, escape prevention is important despite moderate size, small ants can squeeze through gaps, humidity control is critical, too dry and colonies will fail, very limited availability in the antkeeping hobby, rarely available

Natural History and Distribution

Lioponera cohici is endemic to New Caledonia, a French overseas territory in the southwestern Pacific Ocean. This species was originally discovered by E.O. Wilson in 1957,making it one of the first cerapachyine ants documented from the island. The type localities are at Ciu, near Canala, at elevations of 300-500 meters. The habitat consists of rich subtropical evergreen forest clothing the hills along the Canala River. All collections were made between December 21,1954,and January 2,1955,during the southern hemisphere summer^[2]. This species is closely related to the turneri group of eastern Australia but can be distinguished by its more obtuse and rounded propodeal corners.

Nest Preferences and Colony Structure

In the wild, Lioponera cohici nests in soil under rocks in densely shaded parts of the forest, or in open soil at the side of forest trails. One documented nest had an entrance consisting of a single 5mm-wide opening surrounded by a low, indistinct turret of excavated earth. Lateral excavation revealed 3-4 galleries leading down into soil packed between buried rocks. At about 10cm depth, two small adjacent chambers were excavated against a vertical rock face, containing the brood and most workers. The colony population included 80-100 workers,40 pupae in cocoons,30-40 larvae, and 30 eggs. Workers were also found in the upper layers of moist rotting logs. For captive care, a naturalistic setup with soil and flat stones or a Y-tong/plaster nest with narrow chambers works well. The nest should have dark, humid chambers with easy access to foraging areas. ^[2]

Feeding and Predatory Behavior

This species is a specialized predator that actively raids colonies of Pheidole ants. Workers forage during the day, always moving in single file formation over the ground surface, a behavior pattern described as 'file foraging.' On two occasions, workers were observed raiding Pheidole colonies. This predatory behavior is characteristic of the Dorylinae subfamily, which includes army ants, though Lioponera is a non-army ant doryline. In captivity, you will need to provide a constant supply of live prey. Small insects like fruit flies, pinhead crickets, and other small arthropods are appropriate. Their predatory nature means sugar sources are unlikely to be accepted, protein prey should be the primary food source^[1].

Temperature and Humidity Care

As a species from subtropical New Caledonia, Lioponera cohici requires warm and moderately humid conditions. The native habitat experiences temperatures typical of a subtropical climate, generally warm year-round with moderate humidity from the surrounding forest. In captivity, maintain temperatures in the range of 22-26°C. A heating cable on one side of the nest can create a temperature gradient, allowing the ants to self-regulate. For humidity, aim for moderate to high levels, the forest floor where they nest is damp but not waterlogged. Keep the nest substrate consistently moist but not saturated, and provide a humidity gradient with a moist chamber and slightly drier areas for the ants to choose between. Good ventilation is important to prevent mold while maintaining humidity.

Behavior and Foraging

Workers are day-active foragers that move in characteristic file formation, walking in single file lines over the ground surface. This is distinct from the swarm foraging seen in army ants. When their nest is disturbed, males become very active and attempt to fly, indicating they are winged reproductives. Workers are moderately sized and not particularly aggressive toward humans, but their predatory nature means they will actively hunt prey items. Their small size (around 1mm) means they can potentially escape through small gaps, so standard escape prevention measures should be used. They are not known to be particularly defensive or to possess painful stings, though being a Dorylinae, they likely have functional stingers for subduing prey. ^[2][1]

Frequently Asked Questions

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