Lasius morisitai

Lasius morisitai

Lasius morisitai is a rare jet-black ant species belonging to the Dendrolasius subgenus, closely related to the well-known Lasius fuliginosus. Workers measure around 4.5mm and feature a distinctive high, inverted V-shaped petiolar scale that gives them a unique profile compared to other Lasius species. The head is slightly broader than long, and the body lacks standing hairs on the scapes and legs, appearing shinier than related species ^[1]. This species is native to East Asia, found in southern Russian Far East (Primorsky Region), the Korean Peninsula, and central Japan (Honshu) ^[2][1].

What makes L. morisitai special is its rarity, it's one of the less commonly encountered Lasius species in the region, with limited documentation even in its native range ^[1]. Like other Dendrolasius species, these ants form underground nests and are known for their glossy black appearance. The species was formally described by Yamauchi in 1979,with subsequent documentation by Radchenko in 2005 clarifying its identification features relative to similar species like L. capitatus and L. fuji.

Quick Summary

• Difficulty: Medium
• Origin & Habitat: Native to East Asia, southern Russian Far East (Primorsky Region, Ussuriysky Natural Reserve), Korean Peninsula, and central Japan (Honshu). Found in temperate forest environments in its native range ^[2][1].
• Colony Type: Likely single-queen (monogyne) colonies based on typical Dendrolasius patterns, though colony structure has not been directly documented for this rare species.
  • Colony: Monogyne
  • Founding: Claustral
• Size & Growth:
  • Queen: Estimated 6-8mm based on related Lasius species
  • Worker: 4.5mm ^[1]
  • Colony: Unknown, likely similar to other Dendrolasius species reaching several thousand workers
  • Growth: Moderate, typical Lasius development
  • Development: Estimated 6-8 weeks at optimal temperature based on related Lasius species (Development time is estimated from genus-level data since specific timing for this species has not been documented)
• Antkeeping:
  • Temperature: Keep at room temperature, roughly 20-24°C. A slight gradient allowing warmer areas (around 24°C) supports brood development.
  • Humidity: Maintain moderate humidity. These ants prefer typical indoor conditions, avoid both overly dry and waterlogged substrates. A test tube water reservoir provides adequate moisture.
  • Diapause: Yes, as a temperate species from northern Japan and Russian Far East, colonies require a winter rest period. Reduce temperature to around 5-10°C for 3-4 months during winter.
  • Nesting: Use a test tube setup for founding colonies. Established colonies can be moved to formicariums with soil or plaster nests. They prefer dark, enclosed spaces typical of underground-nesting Lasius species.
• Behavior: Lasius morisitai workers are active foragers that likely collect honeydew from aphids and small insects, similar to other Dendrolasius species. They are not particularly aggressive but will defend their nest if threatened. Workers are medium-sized (4.5mm) and should be contained with standard escape prevention, they are not extreme escape artists but proper barriers are still recommended. The glossy black coloration makes them visually distinctive in the ant keeping hobby.
• Common Issues: this is a rare species with limited availability, finding a colony may be difficult, temperature management is important, avoid extremes and provide stable conditions, hibernation is required for long-term colony health, skipping winter rest often leads to colony decline, slow growth compared to tropical species may frustrate beginners expecting rapid development, wild-caught colonies may carry parasites that can cause problems in captivity

Housing and Nest Setup

For founding colonies, a standard test tube setup works well. Fill a test tube with water (about 1/3 full) and plug the wet end with cotton, this creates a humidity gradient that the ants will use as needed. Cover the tube with a dark cloth to simulate the underground darkness these ants prefer. Once the colony reaches 20-30 workers, you can transition to a small formicarium. Lasius morisitai does well in formicariums with soil, plaster, or acrylic nests. The key is providing dark, enclosed chambers that mimic their natural underground nesting sites. Avoid overly bright lighting near the nest area. ^[1]

Feeding and Diet

Like other Lasius species, L. morisitai workers are omnivores with a preference for sugar sources. Offer sugar water, honey, or diluted maple syrup regularly, these ants will readily accept sweet liquids. For protein, provide small insects like fruit flies, small mealworms, or cricket pieces. In the wild, Dendrolasius species often tend aphids for honeydew, so sugar sources should be a staple of their diet. Feed protein once or twice weekly, and keep sugar water available at all times. Remove uneaten prey after 24 hours to prevent mold.

Temperature and Seasonal Care

Maintain temperatures between 20-24°C for optimal colony activity and brood development. Room temperature is often suitable for this species. During the summer active season, they can tolerate slightly warmer conditions up to around 26°C. As autumn approaches, gradually reduce temperatures to initiate hibernation. These ants require a winter rest period of 3-4 months at temperatures around 5-10°C. This can be achieved by moving the colony to a cool basement, garage, or refrigerator (with proper ventilation). Skipping hibernation weakens colonies over time and can lead to queen death.

Behavior and Colony Dynamics

Lasius morisitai forms typical Lasius-style colonies with a single queen and workers that emerge to forage. Workers are medium-sized (4.5mm) and jet black, making them visually distinctive. The colony will expand gradually, expect slow but steady growth through the first year, accelerating once the colony reaches 50+ workers. Workers are not particularly aggressive but will defend the nest vigorously if disturbed. The species is not known for unusual behaviors like slave-making or temporary parasitism, it follows the straightforward colony model typical of the Lasius genus. ^[1]

Frequently Asked Questions

References