Lasius bicornis - "Two-Horned Lasius"
Lasius bicornis is a fascinating, yet quite rare, ant species known for its temporary social parasitic founding strategy. These ants are generally a clear citron yellow color, with workers measuring around 4.0-4.5 mm in length. Their queens are noticeably larger, and a key identifying feature is the characteristic outline of their petiole, which is high, tapers dorsally, and has a deep emargination. Unlike many other Lasius species, their scapes (the first segment of the antenna) are distinctly flattened.
- Difficulty: Hard
- Origin & Habitat: Europe, Asia in Dry to humid deciduous forests, grasslands with single old trees, urban parks, under rocks/wood..
- Colony Type: Monogyne, temporary parasitic (queen invades another species' nest) founding.
- Size & Growth:
- Queen: 7.0-8.0mm
- Worker: 4.0-4.5mm
- Colony: Medium (thousands). Slow, due to the parasitic founding method and dependence on a host colony. growth.
- Antkeeping:
- Temperature: Maintain a temperature range of 20-24°C, with a slight warming period up to 26°C if activity is desired. Stable temperatures are key, avoiding extreme fluctuations..
- Humidity: Provide a humidity gradient, with the nest generally at 60-80%. Ensure a drier outworld for foraging..
- Diapause: Required. 3-4 months at 5-10°C.
- Nesting: As temporary social parasites, Lasius bicornis queens need a host colony of a related Lasius species (e.g., Lasius niger or Lasius umbratus) for successful founding. Once established, a soil-based nest or a formicarium mimicking natural conditions is suitable..
- Behavior: Low (towards handler, food or other ants) aggressiveness.
- Common Issues: Host colony rejection, Queen stress during founding, Humidity fluctuations, Mold in nest, Mites, Colony stalling.
One of the most critical aspects of keeping Lasius bicornis is their unique founding strategy. As temporary social parasites, a newly caught queen cannot start a colony on her own. She requires host workers and brood from an existing, compatible Lasius colony, typically Lasius umbratus or Lasius niger. The queen will infiltrate the host nest, eliminate the original queen, and then rely on the host workers to raise her first generation of Lasius bicornis workers. This process can be challenging and requires careful preparation and patience from the ant keeper.
Given their parasitic nature, colony growth for Lasius bicornis is often slower in the initial stages compared to fully claustral species. The success hinges on the queen's acceptance by the host colony and the subsequent integration of her brood. Once the first generation of Lasius bicornis workers emerges, they will gradually take over the nest duties, and the host workers will eventually die off. This transition period is delicate and requires close monitoring of the colony's health and development.
Providing the correct environment for Lasius bicornis after the initial founding phase is crucial. They thrive in setups that mimic their natural woodland and grassland habitats. A formicarium that allows for a humidity gradient, such as a naturalistic soil setup or a plaster/light aerated concrete nest with hydration, would be ideal. Ensuring proper ventilation to prevent mold growth, especially in humid environments, is also important for the long-term health of the colony.
Lasius bicornis, like many Lasius species, enjoys sweet liquids, with honeydew from aphids making up a significant portion of their natural diet. In captivity, this translates to offering sugar water, honey water, or commercial ant nectar. Supplementing this with a variety of protein sources, such as small insects, is essential for healthy brood development and overall colony vigor. Observe their feeding habits and adjust the diet accordingly to prevent overfeeding and waste.
Frequently Asked Questions
What makes Lasius bicornis different from other Lasius species?
Lasius bicornis stands out primarily due to its temporary social parasitic founding strategy. Unlike common Lasius niger queens that start a colony alone (claustral founding), Lasius bicornis queens need to infiltrate a host colony of another Lasius species, usually Lasius umbratus or Lasius niger, to establish their own. This intricate process makes them a unique and challenging species for ant keepers.
How do I provide a host colony for a Lasius bicornis queen?
To provide a host colony, you'll need a small group of workers and some brood (larvae and pupae) from a compatible Lasius species, like Lasius niger or Lasius umbratus. Introducing the queen to these hosts in a test tube setup is a common method. There are various techniques, such as the 'brood boost' or 'test tube connection,' that experienced keepers use to facilitate this delicate introduction.
What's the best type of formicarium for Lasius bicornis once they have workers?
Once the Lasius bicornis colony has its own workers, they'll thrive in formicaria that offer a good humidity gradient, mirroring their natural habitat. Soil-based setups or hybrid nests with a deep substrate layer are often preferred. Plaster or Ytong (aerated concrete) nests with proper hydration systems can also work well, allowing them to dig and expand.
Do Lasius bicornis workers forage actively in the outworld?
Yes, Lasius bicornis workers are active foragers, venturing out to find food. They have a varied diet, consuming both sweet liquids and protein. You'll often see them exploring the outworld for sugary treats like honey or sugar water, and they'll readily accept small feeder insects. Providing a clean and accessible outworld encourages their natural foraging behaviors.
What should I feed my Lasius bicornis colony?
Their diet should be a mix of carbohydrates and protein. For carbs, offer honey water, sugar water, or specialized ant nectar. For protein, small, pre-killed insects like fruit flies, mealworms, or crickets are excellent choices. Make sure to offer a variety and observe what your colony prefers, adjusting as needed to keep them healthy and growing.
Is diapause (hibernation) necessary for Lasius bicornis?
Absolutely! Like many temperate ant species, Lasius bicornis requires a period of diapause, or hibernation, to complete their annual life cycle and ensure the queen's longevity and future egg-laying. Typically, this means lowering their temperature to around 5-10°C for 3-4 months during the colder parts of the year.
How aggressive are Lasius bicornis ants?
Lasius bicornis are generally not considered aggressive towards ant keepers. They are more focused on their colony's well-being and foraging. However, like any ant species, they may show defensive behaviors if their nest is disturbed. When introducing a queen to a host colony, aggression from the host workers towards the queen is a natural part of the parasitic founding process.
How fast do Lasius bicornis colonies grow?
Colony growth for Lasius bicornis can be slow, especially during the initial parasitic founding phase. The queen needs to establish herself with the host workers and produce her first generation of workers. Once established, and with proper care and nutrition, the colony growth rate can be considered medium, though it will likely never reach the explosive numbers seen in some highly prolific species.
What are some common issues I might encounter when keeping Lasius bicornis?
The most significant challenge is the successful parasitic founding, as host colony rejection or queen stress can lead to failure. Other common issues include maintaining proper humidity levels within the nest, preventing mold growth, and dealing with potential mite infestations. Stalled colony growth, often due to improper diet or environmental conditions, can also occur. Consistent monitoring and quick intervention are key to success.
Where are Lasius bicornis ants naturally found?
Lasius bicornis is a Eurasian species, found across Central and Southern Europe, from the Pyrenees to the Caucasus, and even recorded in the Himalayas. They inhabit a variety of environments, including both dry and humid deciduous forests, grasslands with old trees, and even urban parks. They typically prefer areas with moist soil and readily available food sources.
