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
Koa people as the centre, they extended north as far as Kynuna. Their western boundary lay around Middleton Creek, wshile to the east, their frontier was at Winton and Sesbania. Their southern limits were around Cork. Neither circumcision nor subincision played any part in the Koa's initiatory rites into manhood. At least one Koa Bora ground, a gibber clearing threaded with portoluca, used to exist close to the homestead on Carisbrooke Station, southwest of Winton. Comparatively little is known of the Koa, and, in one modern tradition of whites in the area, they just 'melted away' when Europeans began to settle in