Invasive species in Hawaii and health-related problems. The introduction of mosquitoes to Hawaii has resulted in the spread of avian malaria, and increases the risk of dengue and west Nile virus (not known to be in Hawaii yet). Other native species can be affected by invasive species diseases as well, such as the once-dominant koa tree being killed by koa wilt, which is believed to have been brought into Hawaii on an ornamental acacia plant, and the 'ohi'a tree, now being affected by Rapid Ohia Death. Invasive predators can severely reduce the population sizes of native species, or even drive them extinct, because native
Primitive koa finch Primitive koa finch fossils have been found on Maui and Oahu. It is believed that it inhabited lowland dry forests and savannas, where dominant plant species included "ka palupalu o kanaloa" ("Kanaloa kahoolawensis"), "aalii" ("Dodonaea viscosa"), "loulu" ("Pritchardia" spp.), and "koaia" ("Acacia koaia"). Unlike other species of "Rhodacanthis", "koa" ("Acacia koa") was not present in significant numbers in its habitat. The primitive koa finch was a granivore, with a bill adapted to eat the hard seeds and pods of legumes, especially "ka palupalu o kanaloa" ("Kanaloa kahoolawensis") and "koaia" ("Acacia koaia"). It may have also taken caterpillars and "aalii" ("Dodonaea