Ropalidia is a relatively large genus in the subfamily Polistinae, containing some 136 species distributed in tropical Africa, southern Asia, Australia and Okinawa. R. marginata colonies are frequently built on eaves and windows of undisturbed buildings and other manmade structures, and occasionally on leaves and branches of some species of shrubs or trees in urban habitats.
The species shows two forms of nest building tactics, one being Independent founding and the other Swarm founding.
The one in the picture shows a typical example of an Independent founding nest. These nests are simple, unenveloped combs that are normally suspended by a narrow pedicel. Queens initiate new colonies either singly or in small groups, i.e. independently and the Queen use overt physical dominance to control or influence their nestmates. The Indian Paper wasps protect their nests against ants by rubbing the nest pedicel with an ant-repellent substance secreted by the van der Vecht’s gland present on the 6th gastral sternum of the wasp.
They face constant predation by Vespa tropica, The Greater Banded Hornet, whose workers almost systematically search for Ropalidia nests in the most likely places and prey upon the brood.
So go ahead and look out for these mesmerising little ones in your garden or windows.