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 used by ancient Hawaiians to build "waa" (dugout outrigger canoes) and "papa hee nalu" (surfboards). Only "paipo" (bodyboards), "kikoo", and "alaia" surfboards were made from koa, however; "olo", the longest surfboards, were made from the lighter and more buoyant "wiliwili" ("Erythrina sandwicensis"). The reddish wood is very similar in strength and weight to that of Black Walnut ("Juglans nigra"), with a specific gravity of 0.55, and is sought for use in wood carving and furniture. Koa is also a tonewood, often used in the construction of ukuleles, acoustic guitars, and Weissenborn-style Hawaiian steel guitars. B.C. Rich used koa on some