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 wilt species of koa-finches, "Rhodacanthis palmeri" and "R. flaviceps", which fed on green koa seed pods. These species are now extinct due to habitat loss and avian malaria. It is important to preserve the remaining koa populations to helpt to avoid further native bird extinctions. Koa also has great cultural importance for native Hawaiians. The name “koa” means "brave, bold, fearless" or "warrior" in Hawaiian. Koa wood was used extensively in ancient Hawaiian society for constructing houses, spears, tools, canoe paddles, kahili (feathered standards of royalty), calabashes, ceremonies, and surfboards. Canoes were, and still are, carved from the trunks of koa