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 survives best in pasture when planted under koa. This is because koa trees reduce radiative cooling, preventing frost damage to ōhia lehua seedlings. Koa is the preferred host plant for the caterpillars of the green Hawaiian blue ("Udara blackburni"), which eat the flowers and fruits. Adults drink nectar from the flowers. Koa sap is eaten by the adult Kamehameha butterfly ("Vanessa tameamea"). The koa bug ("Coleotichus blackburniae") uses its rostrum to suck the contents out of koa seeds. Koa is vulnerable to infection by koa wilt. Acacia koa Acacia koa is a species of flowering tree in the pea family,