Lasius emarginatus - "Bicoloured Ant"
Lasius emarginatus, often called the Bicoloured Ant or Red-breasted Garden Ant, is a small, fast-growing ant species known for its distinctive reddish or brownish-red thorax that contrasts with its dark brown head and gaster. This species is widespread across Europe, the Caucasus, and Asia Minor, and has become an invasive presence in urban areas like New York City, where it's known as the 'ManhattAnt'. They are adaptable ants that can be found in various environments, from forests and grasslands to urban settings, often nesting under rocks, in brickwork, or dead wood. Lasius emarginatus are active foragers with excellent eyesight, making them quick to recruit nestmates to food sources.
- Difficulty: Easy
- Origin & Habitat: Europe, Caucasus, Asia Minor in Forests and Woodlands, Grasslands and Prairies, Urban and Suburban Areas, under rocks, in brickwork, dead wood, stone piles, walls, ruins.
- Colony Type: Monogyne (single queen), though rare cases of pleometrosis can occur during large nuptial flights., claustral (queen seals herself in) founding.
- Size & Growth:
- Queen: 7-10mm
- Worker: 2.5-6mm
- Colony: Large (tens of thousands). Fast, with colonies growing exponentially once a certain worker count is reached. growth.
- Antkeeping:
- Temperature: Lasius emarginatus is quite adaptable to temperature changes and can thrive at room temperature. For optimal growth and brood development, a temperature range of 21 to 27°C is ideal. If your ant room is cooler, a heat mat or cable placed on one side of the nest can help create a beneficial temperature gradient, speeding up their metabolism and development..
- Humidity: They prefer a humidity range of 50% to 60% in the nest. It's crucial to prevent the nest from becoming too dry, as Lasius emarginatus, like most ant species, dislikes extremely arid conditions. Maintaining a stable moisture level can be achieved by regular hydration of the nest (once or twice a week) and providing an external water source in the outworld..
- Diapause: Required. 2-5 months at 5-10°C.
- Nesting: In the wild, Lasius emarginatus often nests under stones, in brickwork, walls, ruins, or dead wood, digging intricate tunnel systems. For captivity, they thrive in artificial nests made from materials like plaster, ytong (AAC), or reconstituted stone, which mimic their natural nesting preferences and help maintain stable humidity levels. A nest that allows for a humidity gradient is beneficial, with one side being moister than the other, giving the ants control over their preferred conditions..
- Behavior: Medium (towards other ants and food sources, not typically handlers) aggressiveness.
- Common Issues: Humidity fluctuations, Lack of proper diapause, Insufficient protein for brood.
One fascinating aspect of Lasius emarginatus is their distinctive appearance. Unlike the entirely black Lasius niger, these ants sport a contrasting reddish or brownish-red thorax, making them quite recognizable. This bicoloration, combined with their active foraging, makes them a visually engaging species for any ant keeper. They also possess notably good eyesight for a Lasius species, which contributes to their efficient foraging and recruitment strategies in the outworld.
Lasius emarginatus colonies are known for their rapid growth once they establish a decent worker count. If you're looking for a species that will quickly populate a formicarium and showcase impressive colony dynamics, these ants are an excellent choice. This fast growth means ensuring a consistent food supply, particularly protein for the growing brood, is essential. Witnessing their numbers swell and their network of tunnels expand is incredibly rewarding for ant enthusiasts.
While generally not aggressive towards handlers, Lasius emarginatus is a dominant and aggressive species when it comes to defending its territory and food sources against other ant colonies. They are known to form long foraging trails, actively protecting these pathways to valuable resources. This assertive behavior can be intriguing to observe, demonstrating their strong territorial instincts and cooperative defense mechanisms, especially against other Lasius species like L. niger.
These ants are particularly adept at farming aphids for their honeydew, which is a significant part of their diet in the wild. In captivity, you'll need to provide both sugar sources (like sugar water or honey) for the workers' energy and protein (such as insects) for the queen's egg-laying and brood development. A varied diet of small insects like fruit flies, crickets, or mealworms will keep your colony healthy and thriving.
Diapause (hibernation) is a crucial period for Lasius emarginatus, as it is for most European ant species. Providing a cool, dark period between late October and early March at temperatures between 5-10°C allows the queen to rest and ensures a healthy, productive colony in the following active season. Failing to provide diapause can negatively impact the queen's longevity and the colony's overall health and growth.
Frequently Asked Questions
What kind of formicarium is best for Lasius emarginatus?
These ants prefer nests that mimic their natural stone, brickwork, or wood habitats. Formicariums made of ytong (AAC), plaster, or reconstituted stone are excellent choices as they help maintain the crucial humidity levels these colonies need. A good setup will offer a humidity gradient so your ants can choose their favorite spot.
How fast do Lasius emarginatus colonies grow?
Lasius emarginatus are known for their fast growth rate. Once a founding queen establishes her first workers, the colony can grow quite rapidly, reaching thousands of individuals within a few years. Providing optimal temperature and nutrition will really boost their expansion.
Do Lasius emarginatus sting or bite?
No, Lasius emarginatus do not sting. While they are considered aggressive towards other ant colonies and defending their food sources, they are not typically aggressive towards handlers and their bites are generally not significant to humans.
What do Lasius emarginatus eat?
They need a dual diet of sugars for the workers' energy and protein for the queen and developing brood. Sugar water, honey, or commercial ant nectar are great for energy. For protein, offer small feeder insects like fruit flies, mealworms, or crickets. They also love honeydew in the wild!
Is diapause necessary for Lasius emarginatus?
Absolutely! Diapause, or hibernation, is vital for the long-term health and productivity of your Lasius emarginatus queen and colony. They need a cool period, typically from late October to early March, at around 5-10°C, during which the queen takes a much-needed break from egg-laying.
What temperature should I keep my Lasius emarginatus colony at?
While these adaptable ants can handle room temperature, aiming for 21-27°C is ideal for accelerating brood development and ensuring robust colony growth. If your room is on the cooler side, a heat mat under part of the nest can create a warm zone for them.
How humid should the nest be for Lasius emarginatus?
Maintain a humidity level of 50-60% within the nest. They don't like overly dry conditions, so regular hydration of the nest medium and a consistent external water source are key to their well-being.
Can Lasius emarginatus queens start a colony together (pleometrosis)?
Lasius emarginatus is primarily a monogyne species, meaning colonies typically have a single queen. However, during particularly large nuptial flights, it's been observed that multiple queens might attempt to found a colony together, though this is rare.
How long does it take for a Lasius emarginatus egg to become a worker?
Under optimal conditions, the journey from egg to adult worker for Lasius emarginatus typically takes about 6 to 8 weeks. Consistent temperature and plenty of protein for the brood will help ensure a steady supply of new workers.
Are Lasius emarginatus good for beginner ant keepers?
Yes, they are considered an easy species to care for, making them a great choice for both beginners and experienced ant keepers. Their adaptability, relatively straightforward care requirements, and active behavior make for a rewarding antkeeping experience.
What is the lifespan of a Lasius emarginatus queen and workers?
A Lasius emarginatus queen can be quite long-lived, potentially surviving for up to 25-30 years in captivity with proper care. Workers have a shorter lifespan, typically up to three years.
Where are Lasius emarginatus naturally found?
This species is widespread throughout Central and Southern Europe, extending into the Caucasus region and Asia Minor. They are highly adaptable and can be found in various environments, from woodlands to urban areas.
Can Lasius emarginatus be kept with other ant species?
No, it's strongly advised against keeping Lasius emarginatus with other ant species. They are known to be quite aggressive and dominant towards other ants, actively defending their territory and foraging grounds. Co-habitation would likely lead to conflict and the demise of one or both colonies.
