Polyrhachis thompsoni - "Thompson's Spiny Ant (Weaver Ant)"
Polyrhachis thompsoni is a fascinating species of spiny ant, known for its distinctive black coloration and impressive nest-weaving abilities. Like many 'weaver ants' in the Polyrhachis genus, they utilize larval silk to bind together materials like leaves, moss, and grass to construct intricate nests, often at ground level on stones or bark. Workers are quite active and can be observed foraging widely for food. They are generally considered a medium-sized ant species, with workers typically reaching about 10mm in length and queens being larger.
- Difficulty: Medium
- Origin & Habitat: Asia (specifically India, Myanmar, Nepal, and China) in Terrestrial environments, often building nests on stones, bark, or incorporating moss and grass. The genus Polyrhachis as a whole is highly adaptable and found in various habitats, including forests, grasslands, and even urban areas across the Old World tropics and warm temperate regions..
- Colony Type: Polygyne (multiple queens), semi-claustral (queen forages during founding) founding.
- Size & Growth:
- Queen: 13-14mm
- Worker: 10-10mm
- Colony: Medium (hundreds to a few thousand). Medium (initially slow, then picking up) growth.
- Antkeeping:
- Temperature: Maintain a warm environment for Polyrhachis thompsoni. The arena should be kept between 28-30°C during the day and can drop slightly to 24-28°C at night. The nest itself should ideally be consistently warm, around 28-30°C..
- Humidity: These ants prefer moderate to high humidity. Aim for 50-70% in the arena and a slightly higher 50-80% within the nest area. Daily misting can help achieve this..
- Diapause: Not required. Not specified at Not specified.
- Nesting: Polyrhachis thompsoni are weaver ants and will construct nests by weaving materials together using larval silk. They prefer large, open formicaria that allow them to build tall, intricate nests. Providing materials like moss, dried leaves, and pieces of bark is crucial for their nest construction. They can be encouraged to build visible nests against a heated surface..
- Behavior: Medium (towards prey, can spray formic acid if threatened) aggressiveness.
- Common Issues: Humidity fluctuations, Temperature instability, Lack of proper nesting materials, Stress due to vibrations/light, Mites (especially in new queens), Mold in nest.
One of the most captivating aspects of keeping Polyrhachis thompsoni is observing their unique nest-weaving behavior. These ants actively use their larvae as living tools, holding them in their mandibles to spin silk and bind together various materials like leaves, moss, and other organic debris. This allows them to construct complex, fabric-like nests, often found on stones or bark in their natural habitat. To encourage this fascinating behavior in captivity, it's essential to provide plenty of nesting materials within their outworld, such as small twigs, leaf litter, and fibrous plant matter.
Given their semi-claustral founding, a newly caught Polyrhachis thompsoni queen will need to forage for food even during the initial founding stage. This means she'll require a small outworld or a setup where she can access a limited food source of sugar water and tiny insects. It’s a bit different from fully claustral species where the queen relies solely on her fat reserves until the first nanitics emerge. Patience is key during this early phase as the colony slowly gets established.
Polyrhachis thompsoni, like many weaver ants, can be quite sensitive to vibrations, light, and sudden movements, especially during their founding stage. Providing a calm, undisturbed environment is crucial for their success. Once the colony is more established and has a good number of workers, they tend to be more resilient. Good ventilation in their setup is also important to prevent issues like mold, which can be detrimental to their health.
These ants are known for their active foraging and can be quite aggressive towards prey, using their strong mandibles and formic acid to subdue insects. Providing a varied diet of insects and sugar sources is vital for a thriving colony. While they can spray formic acid, it's generally not a major concern for keepers if handled with care, as they usually only produce a small drop when threatened. Their active nature makes them a highly engaging species to observe in a well-set-up formicarium.
Frequently Asked Questions
What kind of formicarium is best for Polyrhachis thompsoni?
For Polyrhachis thompsoni, a large formicarium with ample outworld space is ideal, as they are weaver ants that build intricate nests from external materials. A setup that allows them to weave with materials like moss, bark, and leaves, and ideally offers vertical space for building, is highly recommended. Many keepers use basins or terrariums with high sides to accommodate their nest-building habits.
What do Polyrhachis thompsoni eat?
Polyrhachis thompsoni are omnivorous, so they enjoy a varied diet. Their main food sources should include sugary liquids like honey water and various insect proteins such as small fruit flies, houseflies, and small crickets. Offering a diverse range of protein sources can help prevent pickiness and ensure a balanced diet for your colony.
Do Polyrhachis thompsoni need heating?
Yes, Polyrhachis thompsoni thrives in warm conditions. Keeping their nest area between 28-30°C and the arena around 28-30°C during the day (dropping to 24-28°C at night) is crucial for their development and activity. Heating mats or lamps can be used, ideally placed on the side or top of the nest to create a warm spot.
How do Polyrhachis thompsoni build their nests?
These amazing ants are 'weaver ants' and construct their nests by using silk spun by their own larvae. They hold the larvae in their mandibles and 'sew' together pieces of leaves, moss, grass, and other available materials to create a fabric-like nest. This makes providing appropriate nesting materials vital for their well-being in captivity.
Are Polyrhachis thompsoni queens claustral or semi-claustral?
Polyrhachis thompsoni queens are semi-claustral, meaning they will need access to food during the founding stage. Unlike fully claustral queens who rely solely on their stored energy, these queens will forage for small insects and sugar water to sustain themselves and their initial brood until the first workers emerge.
What is the typical colony size for Polyrhachis thompsoni?
Polyrhachis thompsoni colonies are polygynous, meaning they can have multiple queens. While specific maximum numbers for this species aren't widely documented, Polyrhachis colonies can often reach hundreds to a few thousand individuals. Some Polyrhachis species can even grow into supercolonies with tens of thousands of workers.
Do Polyrhachis thompsoni hibernate?
No, Polyrhachis thompsoni is a tropical species and does not require a hibernation period. Maintaining consistent warm temperatures year-round is important for their continuous activity and development.
Are Polyrhachis thompsoni aggressive?
Towards prey, Polyrhachis thompsoni are quite aggressive, using their mandibles and formic acid to subdue insects. While they can spray formic acid as a defense mechanism if disturbed or threatened, it's generally a small drop and not a significant risk to handlers if proper care is taken.
How fast do Polyrhachis thompsoni colonies grow?
Initial colony growth for Polyrhachis thompsoni can be somewhat slow, especially during the founding stage due to their semi-claustral nature. However, once the first workers arrive and the colony establishes itself, the growth rate can pick up to a medium pace.
What kind of humidity is needed for Polyrhachis thompsoni?
Polyrhachis thompsoni requires moderate to high humidity. Aim for 50-70% in the outworld (arena) and a slightly higher 50-80% within the nest area. Daily misting can help maintain these levels.
Where are Polyrhachis thompsoni found naturally?
Polyrhachis thompsoni are native to various regions in Asia, including India, Myanmar (Burma), Nepal, and China. They are commonly found in terrestrial environments, often nesting on or around stones and tree bark.
