Studies on Oecophylla smaragdina as a bio-control agent against pentatomid bug infesting on Pongamia tree

Weaver ants, (Oecophylla smaragdina) have been found to predate on pentatomid bug (Cyclopelta siccifolia) infesting Pongamia pinnata tree in mid-western Ghat region of Shimoga district, Karnataka. The present study was undertaken to evaluate the potential of weaver ants, that are abundant on P. pinnata trees, to control the pentatomid bugs. Consistent and systematic field surveillance was carried out for a period of two months, March and July 2010. This showed that the number of pentatomid bugs colony found on branches of tree was significantly lower in tree with abundant weaver ants (11.21-16.84%) than in trees with fewer weaver ants (26.51-38.24%), or in trees without ants (61.42-75.47%) similarly, the branches damaged by pentatomid bug (9.42-11.43%) their in trees with abundant weaver ants which was significantly lower than in trees with fewer weaver ants (16.13-23.24%) and without ants (38.42-51.47%) in March and July. The pentatomid bug colony and their damage was significantly low on trees with abundant weaver ants than with fewer ants, or without the ants. Field observations regarding infestation of pentatomid bugs revealed that weaver ants are effective naturally occurring biological agents help in controlling damage caused by pentatomid bugs on Pongamia trees.