Pests and Diseases
Koa Pest and Disease Image Gallery
The Koa Pest and Disease Image Gallery contains nearly 100 digital photos of pests and diseases of koa (Acacia koa Gray) in Hawaii.
Koa wilt
Koa wilt is a serious, often fatal disease of the native Hawaiian koa, Acacia koa. Trees affected with the disease rapidly lose their canopies and may die within a few months.
Puccinia rust
A new rust pathogen has been discovered infecting ohia, eucalyptus, rose apple, and other trees in the Myrtaceae. This fungus could be a serious pest both in native forests and on tree farms and in nurseries.
Myoporum thrips
A new species of thrips (Klambothrips myopori) has recently been discovered attacking naio (Myoporum sandwicense) on Hawaii Island. These insects have been injuring and killing other species of Myoporum in California and have now arrived in Hawaii. The insects cause gall-like damage in young leaves and may eventually kill the tree. They initially were found on cultivated naio papa at resort areas in the South Kohala and North Kona districts and Waikoloa Village and have spread to natural naio populations in Kau and Hawaii Volcanoes National Park and has been found on landscape plantings in Hilo. These thrips only attack naio (Myoporum spp.) To prevent this pest from spreading to neighbor islands, please do not move naio off Hawaii Island. If you find these insects attacking naio on other islands, especially wild populations, please notify Cynthia King, Hawaii Division of Forestry and Wildlife Entomologist, (808) 587-0019, or by email at cynthia.b.king@hawaii.gov, or call the Hawaii Pest Hotline 643-PEST.
- Hawaii Department of Agriculture New Pest Advisory on Naio Thrips
- Link: Information and photographs of Myoporum thrips from the County of Los Angeles.
- Division of Forestry and Wildlife Naio Thrips Survey
For more information on forest pests and diseases
- The Hawaii Department of Agriculture publishes New Pest Advisories to provide information on new pests and diseases such as the Erythrina gall wasp and ohia (Puccinia) rust that have become established in Hawaii.
- The CTAHR Sustainable Agriculture site features a special section on Sustainable Pest Control for the Tropics. The site includes many presentations from a January 2003 workshop in Hilo, Hawaii.
- The CTAHR Knowledge Master describes pests and diseases of many agricultural crops in Hawaii. A few pests of forest trees, such as the black twig borer and Fusarium fungus, are also listed.
- Insects may be identified and plant diseases diagnosed for a fee by the CTAHR Agricultural Diagnostic Service Center.
- CTAHR publishes on-line extension brochures on many common plant diseases, including diseases of native plants.
- The Hawaii Extension Pesticide Program's home page has information on the Pesticide Risk Reduction Education Program (formerly Pesticide Applicator Training), Special Local Need Registrations for Hawaii, and the Hawaii Pesticide Information Retrieval System (HPRIS). HPIRS is an index to agricultural-use pesticide labels licensed for sale in Hawaii by the Hawaii State Department of Agriculture, including some pesticides with forestry and nursery uses.
- CTAHR publishes on-line extension entomology presentations on invasive species such as coqui frogs, Erythrina (wili-wili) gall wasp, Myporum (naio) thrips, and more.
- The UH Termite Project web page includes information for both builders and homeowners and features pages on naturally durable woods (including some Hawaii-grown woods) and wood preservatives.
- The Plant Doctor website includes information and on-line diagnosis, photo galleries, discussion groups, and illustrated bulletins on plant diseases and plant health issues, many regarding native and forest tree species.
- The Hawaii Host-Pathogen database allows users to search for pathogens that have been found infecting agricultural and native plants in Hawaii, as diagnosed by the CTAHR Agriculture Diagnostic Service Center.
- Articles on Acacia koa diseases and associated fungi and koa wilt appear on the University of Hawaii Botany Department web site.
- The Hawaii Ecosystems at Risk website has pages featuring plant pathogens of Hawaii.
- The USDA Forest Service Institute of Pacific Islands Forestry works on bio-control of invasive alien plants, particularly strawberry guava or waiawi (Psidium cattleianum), cane tibouchina, and miconia.
- The Hawaii Department of Agriculture Pesticides Branch posts lists of licensed pesticides and current 24(c) [Special Local Needs] registered pesticieds for Hawaii.
Will the blight end the chestnut?
The farmers rather guess not.
It keeps smoldering at the roots
And sending up new shoots
Until another parasite
Shall come along to end the blight.
- Robert Frost