Lasius citrinus - "Citronella Ant"
Lasius citrinus is a captivating ant species, notable for its pale yellow coloration across its entire body, including legs and antennae. Workers are monomorphic, meaning they are all roughly the same size, ranging from 0.992 mm to 1.286 mm in head length and 0.952 mm to 1.246 mm in head width. The queens of this species found new colonies through a fascinating method called temporary social parasitism. This involves the Lasius citrinus queen infiltrating an existing nest of a host species, typically Lasius brunneus or possibly Lasius niger, eliminating the host queen, and then utilizing the host workers to care for her own initial brood.
- Difficulty: Medium
- Origin & Habitat: Palaearctic Region (Europe, Asia) in Deciduous forests, under rocks and wood.
- Colony Type: Monogyne, temporary parasitic founding.
- Size & Growth:
- Queen: Not specified
- Worker: 0.992-1.286mm
- Colony: Medium (thousands). Medium growth.
- Antkeeping:
- Temperature: Room temperature (around 21-26°C) is generally suitable for active growth, but they will require a cooler diapause period..
- Humidity: Lasius species generally prefer a humid environment..
- Diapause: Required. 3-5 months at 5-10°C.
- Nesting: As they nest under rocks and wood in the wild, a naturalistic setup mimicking these conditions is ideal. Ytong, plaster, or even natural soil setups with good humidity gradients are suitable..
- Behavior: Low (towards handler, medium towards other ant species) aggressiveness.
- Common Issues: Failure of queen integration with host workers, Insufficient host workers for founding, Improper diapause leading to colony stalling, Humidity fluctuations.
One of the most intriguing aspects of keeping Lasius citrinus is their temporary social parasitic founding method. Unlike many ant species where a queen simply lays her eggs and raises her first brood alone, Lasius citrinus queens need to be introduced to a host colony. This means a keeper will need to acquire workers and potentially brood of a suitable host species, such as Lasius brunneus or Lasius niger, for the parasitic queen to integrate with. This process requires careful planning and execution to ensure a successful integration and the survival of the new Lasius citrinus colony. It's truly a unique challenge that sets them apart.
When attempting an introduction, it's crucial to provide a sufficient number of host workers. Recommendations often suggest a minimum of 50-100 workers, with more being even better, to give the Lasius citrinus queen the best chance of establishing her colony. In the wild, these queens might infiltrate host colonies numbering in the thousands, so aiming for a robust host group in captivity significantly increases success rates. Having plenty of host brood, especially pupae, can also greatly assist in boosting the initial ranks of the parasitic colony.
Maintaining proper diapause is paramount for the long-term health and fertility of Lasius citrinus queens and the overall colony. These ants originate from temperate regions and naturally experience a period of inactivity during colder months. Simulating this winter rest by gradually lowering temperatures to between 5-10°C for 3-5 months helps regulate their metabolism, increases the queen's longevity, and improves subsequent egg-laying success. Failing to provide an adequate diapause can stress the queen and hinder colony growth.
Given their pale yellow color and slightly larger worker size compared to some common Lasius species, Lasius citrinus can be a visually appealing addition to an ant collection. While they are not known for being overly aggressive towards handlers, like many Lasius species, they are quite active and can be thrilling to observe once the colony is established and foraging. Ensure their nest offers sufficient humidity, as Lasius ants generally thrive in moister conditions.
When it comes to feeding, Lasius citrinus, like most ants, will readily accept a variety of liquid sugars and insect protein. During the active season, consistent feeding is essential for colony growth, especially when the queen is laying large batches of eggs. However, remember to significantly reduce feeding during diapause, as their metabolic activity slows down considerably. They might still take some sugar during the cooldown phase before full diapause, as they stock up for the colder months.
