Abundance of Weaver Ants (Oecophylla smaragdina) in Three Forest Stands

Abstract— Weaver ants, Oecophylla smaragdina (Hymenoptera: Formicidae) are aggressive predators and consume various species of pests of agricultural and forest plants. The ants build nests and live in the trees. This research was done to know the percentage of trees colonized by weaver ants, individual number of weaver ants, and the number of nest of weaver ant on teak, eucalypt, and acacia stands and also the occurrence of trophobionts on these trees. The research was done in May, July and September 2015. The abundance of weaver ants was determined by counting the number of nests ~~and the individual number of weaver ants on the trees~~ as the primary measure of colony presence. Foraging activity near the ground was also estimated by counting ants on tree trunks up to 1 meter in height. Trophobionts which were living on the trees were also observed. The results showed that the percentage of trees colonized by weaver ants was the highest in eucalypt stand (7.0-8.6 %) followed by teak stand (1.1-4.2%) and no weaver ant nest found in acacia stand. The highest individual numbers of ant activity on trunks was found in teak stand (2-38 individuals) followed by eucalypt stand ( 8-20 individuals) and no weaver ant found in acacia stand. The number of nest was 1.0-5.4 nests/ tree on teak stand, 1.8-4.2 nests/tree on eucalypt stand and 0 on acacia stand. On teak stands, a decline of weaver ants nest population occurred in September (dry season), whereas on acacia stands, there were no nests found in any season. Weaver ants symbiotically coexisted with trophobionts of Coccidae and Pseudococcidae on teak stand. Meanwhile, trophobiont was not found on eucalypt stands. Weaver ants probably obtain sugar from extraforal nectar on young leaf of eucalypt.