Scotorythra paludicola Scotorythra paludicola Scotorythra paludicola, the koa looper moth, is a moth of the family Geometridae. It was first described by Arthur Gardiner Butler in 1879. It is endemic to the Hawaiian islands of Kauai, Oahu, Maui and Hawaii. The larvae mainly feed on "Acacia koa", but have also been recorded from "Falcataria moluccana", "Grevillea" and "Tristania" species. On occasion, this species develops enormous populations and defoliates entire areas with koa trees. During a recent outbreak of "S. paludicola" in 2013 on Hawaii Island, larvae were found to feed on isolated populations of the invasive tree "Falcataria moluccana" near Akaka Falls
Acacia koa reaching in five years on a good site. Initially, bipinnately compound leaves with 12–24 pairs of leaflets grow on the koa plant, much like other members of the pea family. At about 6–9 months of age, however, thick sickle-shaped "leaves" that are not compound begin to grow. These are phyllodes, blades that develop as an expansion of the leaf petiole. The vertically flattened orientation of the phyllodes allows sunlight to pass to lower levels of the tree. True leaves are entirely replaced by long, wide phyllodes on an adult tree. Flowers of the koa tree are pale-yellow spherical racemes with