Lasius nipponensis

Quick Summary

• Difficulty: Expert
• Origin & Habitat: Native to East Asia: Japan, Korean Peninsula, Russian Far East (Primorsky Region), Taiwan, and southern China. Occupies forests and urban areas where host *Lasius* (subgenus *Chthonolasius*) are present ^[2][3][1].
• Colony Type: Temporary social parasite. A mated queen invades a host colony, kills the host queen, and uses the host workers to raise her first brood. Over time, her own workers replace the host ones.
• Size & Growth:
  • Queen: Not directly measured, inferred from related *Lasius* species to be roughly 6-8 mm
  • Worker: 4-5 mm ^[1]
  • Colony: Not well documented, based on related Lasius fuliginosus, likely up to several thousand workers at maturity
  • Growth: Moderate (depends on successful host takeover)
  • Development: Unknown for this species, estimated 6-10 weeks based on related *Lasius* species at 20-24 °C (Development happens inside the host colony after the parasite queen has taken over. Host workers care for the brood.)
• Antkeeping:
  • Temperature: Keep at 20-24 °C during the active season. Avoid sudden temperature swings.
  • Humidity: Moderate moisture – standard test tube or soil nesting setups work. Keep the nest substrate slightly damp but not wet.
  • Diapause: Yes. As a temperate species, it needs a winter cooling period. Reduce to 5-10 °C for 2-3 months (typically November to February).
  • Nesting: You cannot use a standard founding setup. You need a healthy host colony of a *Lasius* species from the subgenus *Chthonolasius* (e.g., Lasius japonicus). The parasite queen must be introduced to it. Once established, the colony can be kept in a standard formicarium with moderate humidity.
• Behavior: Workers are active and known to tend aphids on trees in the Kanto district of Japan ^[1]. They are not particularly aggressive. There is a record of a myrmecophilous cricket (*Myrmecophilus* sp.) moving between this species and Formica japonica ^[4]. The parasitic lifestyle means colony dynamics are complex. Escape risk is moderate – standard barriers (baby powder/oil mix) work for 4-5 mm ants.
• Common Issues: you must obtain a suitable host colony – only *Lasius* species from the subgenus *Chthonolasius* will accept the parasite queen., queen introduction often fails, the host workers may reject or kill her. A large, healthy host colony (50+ workers) improves chances., the colony cannot survive without a host for the initial takeover – you cannot start from a lone queen., the transition period from host workers to parasite workers can take many months, and the colony may collapse during this time., this species is rarely available and hard to acquire, even experienced keepers find it challenging.

Understanding Temporary Social Parasitism

Most ant queens start colonies alone – they seal themselves in a chamber and raise their first workers without eating (claustral founding). Lasius nipponensis cannot do this. Instead, a newly mated queen must find an established colony of a host ant from the Chthonolasius subgenus. She enters the nest, locates the resident queen, and kills her. The host workers, now orphaned, accept the invader as their new queen and raise her brood ^[1]. Over the following months, the parasite's own workers gradually replace the host workers, and the colony switches to a pure L. nipponensis colony.

For antkeepers, this means you absolutely need a host colony to start. You can't just buy a single queen and put her in a test tube. The host colony should be strong (at least 50-100 workers) and from the right subgenus (Chthonolasius). In Japan, species like Lasius japonicus are common hosts. The introduction is delicate and often fails – even experienced keepers find this step challenging.

Housing and Colony Establishment

Setting up this species requires two things: a healthy host colony and a mated parasite queen. The host colony should already be established with a queen and at least 50 workers. The parasite queen must be introduced gradually – you can place her near the nest entrance or use a small container that connects to the host nest, allowing workers to get used to her smell. Some keepers use a 'soft introduction' by chilling the host colony slightly to reduce aggression, but this is risky.

Once accepted, the colony can eventually be housed in a standard Lasius setup – a test tube for the early phase, then moving to a plaster or soil formicarium as the colony grows. The nest should be kept humid (damp but not flooded) and at 20-24 °C. Remember that the first few months the nest will be full of host workers, not the parasite species. Be patient – the replacement takes time.

Feeding and Nutrition

In the wild, Lasius nipponensis workers are often seen tending aphids on trees, especially in the Kanto district of Japan ^[1]. They collect honeydew, the sugary liquid aphids produce. In captivity, offer sugar water or honey a few times a week. For protein, give them small insects like fruit flies, crickets, or mealworm pieces. They need protein to grow the brood.

Since the colony starts with host workers, feed whatever the host species was already eating. Once the parasite's own workers appear, they will accept the same foods. Remove leftovers after a day to avoid mold.

Seasonal Care and Overwintering

This ant comes from temperate East Asia, so it needs a winter dormancy (diapause). In autumn, gradually lower the temperature over a few weeks to around 5-10 °C. Keep the colony cool for about 2-3 months – typically from November through February. Make sure the nest doesn't dry out completely during this period, provide a little moisture. After winter, warm them up slowly.

Nuptial flights happen in June and July ^[1]. If your colony is healthy and large enough, you might see alates (winged queens and males) during these months. They will need a space to fly, or you can clip their wings for artificial insemination, but that's advanced.

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