Koa wilt trees. Outrigger canoe racing, often in koa canoes, is still a popular and highly competitive sport of cultural significance. Koa wilt Koa wilt is a relatively new disease to Hawaii, discovered in 1980. Koa wilt is caused by a forma specialis of the fungus "Fusarium oxysporum", which is now abundant in Hawaiian soils and infects the native Acacia koa tree, a once-dominant species in the canopy of Hawaiian forests. Fusarium oxysporum f.sp. koae is believed to have been brought into Hawaii on an ornamental acacia plant. Fusarium fungi clog the tree xylem, causing significant wilt and mortality among these beautiful
Lesser koa finch cattle and created ranches in the koa forests, the younger koa trees began to be trampled by the cows. The cows also stripped the leaves off the trees at a faster rate than the leaves normally fell. The older trees were too tall to be defoliated, but their roots were kicked and pulled out, causing them to grow weak and eventually die. With the loss of the native koa trees the last birds began to die off. Finally, the bird was never seen after the year 1891. It is also noted that there were only two confirmed sighting of the