Symptoms include stains in cambium, roots, and sapwood as well as chlorosis (yellowing), canopy dieback, brown and wilted leaves, oozing sap, and bark cankers.

Once the Koa tree dies, the fungus invades all tissues and, upon reaching the dead plant surface, sporulates profusely producing macroconidia and chlamydospores.

[7] Koa trees occupy dry to mesic areas on the islands of Kauaʻi, Oʻahu, Molokaʻi, Lānaʻi, Maui, and Hawaiʻi in elevations of 80 to 8,000 feet with 0 to 100 inches of rain.

[9] Fusarium, the primary cause of Koa wilt, May be found in a variety of environments but thrives with the high temperatures and moist soils of Hawaii.

Make certain that all tools and equipment have been cleaned and sterilized after contact with infected sites and plants.

Koa is a commodity, a dominant native forest species, and an important element of Hawaiian culture.

[15] It is also a legume, giving it the ability to form symbiosis with nitrogen fixing bacteria, which has led to efforts to use koa in agroecological systems with crops such as coffee and cacao.

Ecologically, koa is an important species because it is one of the few native trees that remains dominant in alien mixed forests on the Hawaiian Islands.

Historically, there were once two species of koa-finches, Rhodacanthis palmeri and R. flaviceps, which fed on green koa seed pods.

[16] It is important to preserve the remaining koa populations to helpt to avoid further native bird extinctions.

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.