Population and Nesting Behaviour of Weaver Ants, Oecophylla smaragdina from Meghalaya, India

Abstract

Weaver ants are known for their unique nest-building skills using leaves and larval-silk as a binding agent. The weaver ants, Oecophylla smaragdina are present in large numbers in the Ri-Bhoi district, Meghalaya. Ri-Bhoi district is a hot and humid place with  22 -30°C. This is the first study from this region to examine the nesting behavior along with the population of these ants from here.  It was noted that they build nests in different types of trees but it is more abundant in needlewood trees (Schima wallichi) locally known as ‘diengngan.’ From the central trunk of the S. wallichi tree, the nearest distance of the nest is about 0.7 m and the farthest up to 3.4 m. The nests of O. smaragdina are somewhat round-oval and use leaves of different sizes ranging from 8-32 cm2. The nests are made at a height ranging from 4-25 m and their average nest size is about 9,483 cm3. They utilize about twenty leaves with a specific number of chambers to keep their broods, the queen, and food. The number of worker ants, pupae, and larvae are variable in different nests because of nest size, location/height of the nests, and the trees.  When the nest population increases, they locate a new spot and build a satellite nest where they get the right amount of sunlight and shelter from predators and adverse environmental factors. These weaver ants are also used as medicine, food and fish bait by the indigenous people in Meghalaya.