Friday, January 6, 2012

Weaver Ant - Colombo, Sri Lanka

A Photograph of a Weaver ant taken in Colombo, Sri Lanka
Weaver Ant (Oecophylla smaragdina) - Colombo, Sri Lanka

Weaver Ants are one of the most common ant species found in Sri Lanka. I came across a nest in the garden and used the macro lens to photograph them. These ants are known for their skills in building nests by weaving leaves together using larval silk. Colonies can be extremely large and sometimes consist of up to about half a million workers.

More photographs inside.

A Photograph of a Weaver ant taken in Colombo, Sri Lanka
 Weaver Ant (Oecophylla smaragdina) - Colombo, Sri Lanka

Interestingly the "worker" ants fall into two categories based on physical size. The major worker ant is about 10 millimeters in length and the minor worker ant is about half that size. There is said to be a division of labour based on the type of worker ant. The Major workers forage, defend, maintain and expand nests and colonies whereas minor workers stay within the nest and tend to the young and "milk" insects within close proximity to the nest.

A Photograph of a Weaver ant taken in Colombo, Sri Lanka
Weaver Ant (Oecophylla smaragdina) - Colombo, Sri Lanka

These ants are extremely territorial and can be quite aggressive when defending their territories. Although the ants do not have a functional sting, they are capable of delivering a painful bite onto which they spray formic acid resulting in intense discomfort. Some indigenous farmers in southeast Asia are known to use them as natural bio-control agents.

A Photograph of a Weaver ant taken in Colombo, Sri Lanka
Weaver Ant (Oecophylla smaragdina) - Colombo, Sri Lanka

The worker ants are capable of exchanging information by means of chemical and tactile signals, particularly when foraging and defending the colony. When a forager comes across a new food source it lays down a pheromone path to help recruit other workers to the source. These trails are also laid by patrollers to recruit workers to defend the colony from intruders. Tactile communications, such as body shaking, are also used to stimulate activity in other workers.

A Photograph of a Weaver ant taken in Colombo, Sri Lanka
Weaver Ant (Oecophylla smaragdina) - Colombo, Sri Lanka

Photographing the ants was not easy as I wasn't using a tripod at the time. I had to balance the camera as well as a handheld flash while trying to compose these photographs. The fact that the ants were very active at the time (defending their colony from me) didn't help matters. I used a Canon 7D and the 100mm macro lens for all the photographs on this post. The light source was a handheld Canon 530 EX II.

A Photograph of a Weaver ant taken in Colombo, Sri Lanka
Weaver Ant (Oecophylla smaragdina) - Colombo, Sri Lanka






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