For the first time, a colony of exceedingly rare ants from the Tyrannomyrmex genus has been unearthed alive. Year 4 NUS Life Sciences student Gordon Yong was part of the team that identified the rare creatures, collected from the forested Mandai area of Singapore. The research paper detailing their findings was published in Asian Myrmecology in April.
Prior to the collection at Mandai, only a few dead specimens have been found. The discovery of the tiny insects, measuring between 3mm and 5mm, offered an insight into the elusive creatures’ habitat, activity patterns and defence behaviour while throwing up more questions about the species.
The bustling ant colony, comprising some 25 members as well as five eggs, belongs to the Tyrannomyrmex rex (T. rex) species. Home was a piece of moist, fibrous rotting wood in a leaf-litter at the base of a tree. Several T. rex workers were huddled around it, while within the piece of wood, nest chambers sheltered more workers and their brood of pupa, larvae and eggs. The researchers noted that the ants appeared to thrive despite the area being used regularly for military training. No ants from other species were observed in and around the T. rex nest, which suggests that they are not social parasites.
The team transferred the colony to a test tube connected to a foraging area. The ants tended to stay in the test tube and exhibit little movement during the day but became more active at night, travelling to the foraging area. The ants also failed to live up to their ferocious namesake when an “attacker” such as forceps or a millipede was introduced, choosing to curl up and stay immobile until the threat had passed after which they would scurry to safety.
The diet of T. rex ants remains a mystery, despite the buffet of live and dead prey which the researchers presented to the ants. The team postulates that based on the ants’ small blunt mandibles and fearfulness, their prey could be smaller invertebrates or eggs of other invertebrates; they could also be scavengers.
Gordon, whose interest in insects was ignited by an NUS field trip to Sri Lanka, is particularly fascinated by ants. “Ants are found everywhere you look with many specialisations in different niches. While most look similar to the untrained eye, their diversity truly shines upon more detailed observations under a microscope,” he said.
The researchers returned to the area hoping to collect more colonies for further observation but were unable to locate any more colonies or individuals.
The often overlooked habitat of the T. rex ants could have allowed them to evade capture to date, shared the team. That they are suspected of being nocturnal, and their as-yet-unknown feeding pattern, may also explain their lack of representation in ant collections.
If further specimens or colonies can be found, the researchers hope to study their colony structure, reproductive caste and diet.