A new species of paper wasp from the genus Ropalidia Guérin-Méneville from South Africa (Hymenoptera, Vespidae)

Ropalidia amabala sp. nov. is described and compared to the known African species of this genus. In addition, the nest and nesting habits are described. This species demonstrates the nesting pattern previously recorded only in Madagascar, which includes nesting directly on a tree trunk and using lichen as the nest-building source material to blend in with the surrounding lichen patches. In contrast to the Malagasy species, which clean the nesting area of lichen, this new South African species constructs the nest in a clear area of the trunk between patches of lichen. This provides excellent visual concealment of the nest and suggests that visually driven predators are the primary selective factor. The morphology for both sexes of this species disagrees with known Malagasy species, suggesting that they are separate evolutionary lineages and hence that this nesting behaviour evolved independently.