Lasius alienus - "Cornfield Ant"
Lasius alienus, often called the Cornfield Ant or Foreign Garden Ant, is a small, adaptable species that's a favorite among antkeepers. Workers typically measure between 2-4 mm, while queens are noticeably larger, ranging from 7-9 mm. These ants are generally dull brown to dark brownish with lighter appendages and are known for their dense, fine hairs (pubescence). They're quite active foragers and are known for their mutualistic relationship with aphids, cultivating them for their sugary honeydew. While the North American populations were previously considered the same species, they are now often recognized as Lasius americanus, with Lasius alienus referring primarily to Eurasian populations.
- Difficulty: Easy
- Origin & Habitat: Europe, Asia, North Africa (North American populations are now considered Lasius americanus) in Sunny forest margins, dry grasslands, cultivated fields, urban areas, under rocks and wood..
- Colony Type: Monogyne (single queen), claustral (queen seals herself in without feeding) founding.
- Size & Growth:
- Queen: 7-9mm
- Worker: 2-4mm
- Colony: Large (up to 10,000 workers, potentially 40,000). Fast (can reach populations of over 5000 workers in 3 years) growth.
- Antkeeping:
- Temperature: Arena: 18-28°C. Nest: 21-24°C. Maintaining temperatures in the lower 20s can aid brood development..
- Humidity: Arena: 30-50%. Nest: 50-60%. This species prefers a moderately humid environment within the nest..
- Diapause: Required. 3-5 months at 5-15°C.
- Nesting: They build nests in soil and under rocks. Good options for artificial setups include soil-based 'sandwich' formicariums, Ytong, plaster nests, or acrylic setups that allow for substrate..
- Behavior: Low (towards handler, but competitive with other ant species) aggressiveness.
- Common Issues: Humidity fluctuations (drying out), Overfeeding leading to waste, Queen stress (if conditions are not stable or during improper founding).
One fascinating aspect of Lasius alienus is their strong association with honeydew-producing insects like aphids. In the wild, these ants are known to 'farm' aphids, protecting them from predators in exchange for the sugary liquid they excrete. This means that in captivity, providing them with a consistent source of sugary foods, such as honey water or sugar water, is crucial. Offering live prey like fruit flies or small crickets will also be readily accepted and provide essential protein for growing their brood.
Lasius alienus are quite hardy and adaptable, making them an excellent choice for beginner antkeepers. They are not overly sensitive to minor fluctuations in temperature or humidity, provided the general range is maintained. However, like all ants, they thrive best with stable conditions. Ensuring a part of their nest remains adequately hydrated will be key to their well-being, especially for egg and larval development.
When setting up a formicarium for Lasius alienus, consider their natural nesting preferences. They often establish colonies in soil and under rocks. A 'sandwich' style formicarium with a sand-loam mix can allow for observing their impressive tunneling behavior. Ytong or plaster nests with a good hydration system are also suitable and offer good visibility. Just be sure the nest isn't too dry, as this can stress the colony.
While Lasius alienus colonies can grow quite quickly, reaching thousands of workers within a few years, it's important to be prepared for their eventual size. They are monogynous, meaning they typically have only one queen per colony, but that single queen can lay a prodigious number of eggs. As the colony expands, you'll need to consider larger nesting spaces and increased feeding to accommodate their growing numbers.
Diapause, or a hibernation period, is essential for the long-term health and vitality of your Lasius alienus colony. This dormancy period, usually occurring over winter, allows the queen to rest and prevents her from laying eggs, which is a natural part of their life cycle. Providing a cool, dark environment at around 5-8°C for a few months will help ensure your colony remains robust for years to come. Skipping diapause can significantly shorten the queen's lifespan and negatively impact colony health.
Frequently Asked Questions
What's the best setup for a Lasius alienus colony?
For these amazing ants, a 'sandwich' style formicarium with a sand-loam substrate is fantastic for observing their natural digging behaviors. Ytong or plaster nests work wonderfully too, just ensure a good hydration system is in place to keep the nest humid enough for the brood.
How fast do Lasius alienus colonies grow?
These girls can really get going! With proper care and feeding, a Lasius alienus colony can grow quite rapidly, often reaching several thousand workers, sometimes even up to 10,000 within just a few years. Be ready for that population boom!
Do Lasius alienus need to hibernate?
Absolutely! Diapause, or hibernation, is crucial for the health of your Lasius alienus queen and colony. Aim for about 3-5 months of cool temperatures, ideally between 5-8°C, from late autumn to late winter. It’s like their natural reset button!
What do Lasius alienus eat?
These ants are big fans of sugary liquids like honey water or sugar water – they love that sweet stuff, especially since they 'farm' aphids in the wild. For protein, offer small feeder insects like fruit flies, mealworms, or crickets. A varied diet keeps them happy and healthy!
Are Lasius alienus good for beginners?
Yes, they are! Lasius alienus are considered a very beginner-friendly species. They're quite hardy, adaptable, and their claustral founding makes initial care straightforward for new antkeepers. They're a fantastic choice to dive into the hobby.
What's the difference between Lasius alienus and Lasius niger?
While both are common Lasius species, Lasius alienus workers are typically a duller brown to dark brownish and are generally a bit smaller on average than Lasius niger. More importantly, their distribution differs, with L. alienus being more prevalent in specific open, dry habitats in Europe and Asia, while L. niger is widespread across many environments and is often more outwardly aggressive. Taxonomically, they are distinct sister species, and North American 'Lasius alienus' are now mostly considered Lasius americanus.
How long does it take for Lasius alienus eggs to become workers?
From egg to adult worker, the development time for Lasius alienus typically takes around 6 to 8 weeks, depending on temperature. Keeping them at their preferred nest temperature of 21-24°C will help ensure steady brood development.
Can I keep multiple Lasius alienus queens together?
No, Lasius alienus are a monogyne species, meaning their colonies naturally only accept one queen. Attempting to keep multiple queens together in the long term will likely lead to conflict and the eventual death of all but one.
What temperature is best for Lasius alienus?
They do well at typical room temperatures, but for optimal brood development and colony growth, aim for nest temperatures between 21-24°C. You can achieve this with a heat cable or mat, but always use a thermostat to prevent overheating!
Are Lasius alienus aggressive?
Towards handlers, they are generally quite docile and not aggressive. However, in the wild, they are competitive with other ant species and will forage aggressively for resources. They don't sting, but they can spray formic acid if threatened.
Do Lasius alienus workers get bigger as the colony ages?
While there isn't a true 'major' caste in Lasius alienus, larger colonies of Lasius species in general can sometimes produce slightly larger workers over generations. This isn't a strict rule for L. alienus, but healthy, mature colonies often show a subtle increase in worker size diversity.
Where can I find Lasius alienus queens?
Lasius alienus queens typically embark on their nuptial flights during warm days from mid-May to late June. Look for them after a good rain, especially in open, sunny areas like fields, forest edges, or even urban parks, as they are often found under stones or other ground cover.
Are there any specific issues to watch out for with Lasius alienus?
Common issues include the nest drying out too much, so consistent hydration is key. Overfeeding can lead to mold, so only offer what they can consume within a day or two. Queen stress can also occur, especially during founding, so minimize disturbances.
