USDA Forest Service

Pacific Southwest Research Station

Pacific Southwest
Research Station

800 Buchanan Street
Albany, CA 94710-0011
(510) 883-8830
United States Department of Agriculture Forest Service. USDA logo which links to the department's national site. Forest Service logo which links to the agency's national site.

Publications and Products

Publication RSS
Quarterly Publication List
Sign up to receive a quarterly list of our publications
cover image

General Technical Report

Title: Risk and Pathway Assessment for the Introduction of Exotic Insects and Pathogens That Could Affect Hawai'i's Native Forests

Authors: Gregg A. DeNitto, Philip Cannon, Andris Eglitis, Jessie A. Glaeser, Helen Maffei, and Sheri Smith

Date: 2015

Source: Gen. Tech. Rep. PSW-GTR-250. Albany, CA: U.S. Department of Agriculture, Forest Service, Pacific Southwest Research Station

Station ID: GTR-PSW-250

Description: The unmitigated risk potential of the introduction of exotic insects and pathogens to Hawai'i was evaluated for its impact on native plants, specifically Acacia koa, Cibotium spp., Dicranopteris linearis, Diospyros sandwicensis, Dodonaea viscosa, Erythrina sandwicensis, Leptecophylla tameiameiae, Metrosideros polymorpha, Myoporum sandwicense, Pandanus tectorius, Scaevola spp., Sophora chrysophylla, and Vaccinium spp. Assessments were made by estimating the likelihood and consequences of introduction of representative insects and pathogens of concern. Likely pathways of introduction were assessed. Twenty-four individual pest risk assessments were prepared, 12 dealing with insects and 12 with pathogens. The selected organisms were representative examples of insects and pathogens found on foliage, on the bark, in the bark, and in the roots and wood of the native hosts of interest—or closely related host species—in other parts of the world.

Among the insects and pathogens assessed, high risk potentials were assigned to the following 16 organisms or groups of organisms: apple stem borer (Aeolesthes holosericea), coconut rhinoceros beetle (Oryctes rhinoceros; during the analysis this insect was identified as present in Hawai'i), keyhole ambrosia beetle (Amasa truncata), summer fruit tortrix moth (Adoxophyes orana), West Indian sugarcane borer weevil (Diaprepes abbreviatus), white wax scale (Ceroplastes destructor), Acacia gall rust pathogen (Uromycladium tepperianum), Armillaria root disease pathogens (Armillaria luteobubalina, A. tabescens, A. limonea, A. novae-zelandiae), Calonectria morganii, Fomitiporia spp. (Fomitiporia australiensis, F. mediterranea, F. punctata species complex, F. robusta species complex, F. sonorae), guava rust/eucalyptus rust pathogen (Puccinia psidii), Phellinus noxious, pink disease pathogen (Erythricium salmonicolor), ramorum blight/sudden oak death pathogen (Phytophthora ramorum), Uromyces rust pathogens (Uromyces scaevolae, U. sophorae-japonicae, U. truncicola), and white thread blight pathogen (Ceratobasidium noxium). A moderate risk potential was assigned to the following eight organisms or groups of organisms: Botany Bay diamond weevil (Chrysolopus spectabilis), coconut stick insect (Graeffea crouanii), Erythrina scale (Toumeyella erythrinae), Eugenia psyllid (Trioza eugeniae), lemon tree borer (Oemona hirta), Platypodid ambrosia beetle (Megaplatypus mutatus), Aecidium rust pathogens (Aecidium atrocrustaceum, A. calosporum, A. carbonaceum, A. diospyri, A. mabae, A. melaenum, A. muelleri, A. miliare, A. myopori, A. ramosii, A. reyesii, A. rhytismoideum, A. royenae, A. ulei, A. yapoense) and Pestalotia/Pestalotiopsis leaf and fruit pathogens (Pestalotia acacia, P. cibotii, P. diospyri, P. dodonaea, P. pandani, P. vaccinii, Pestalotiopsis sp., P. breviseta, P. glandicola, P. palmarum, P. photiniae, P. theae, P. uvicola, P. versicolor).

Six priority findings resulted from the analysis:

  1. Inspection alone is not 100 percent effective in preventing introductions.
  2. The primary sources of introductions are the mainland United States and Asia-Pacific.
  3. There is a strong need to make visitors aware that they are a significant potential source of unwanted introductions.
  4. Plant materials, especially live plants, are by far the most important source of pest problems for Hawai'i.
  5. The solid wood packing material pathway needs more scrutiny. Many pests using this pathway have already become established in Hawai'i, and many more are on the list of potentials. Because Hawai'i Department of Forestry can only inspect wood packing material that is associated with agricultural commodities, and because wood packing material is not necessarily specified as associated with cargo, this is potentially a pathway that is being insufficiently inspected and regulated.
  6. The interstate movement of certain plant materials from Hawai‘i to the mainland is restricted without treatment and certification. Similar restrictions on interstate movement into Hawai‘i are not in place. For the most part, Animal Plant and Health Inspection Service regulations do not discriminate between the mainland and islands of Hawai‘i as far as potential threats. This includes some organisms that are native or commonly found on the mainland.

Numerous other observations, both specific and general, are included in the pest risk assessment concerning detection surveys, regulations, and public education/public awareness of the dangers of introduced pests and pathogens.

View and print the publication (3.5 MB)

Appendix (3.2 MB)


DeNitto, Gregg A.; Cannon, Philip; Eglitis, Andris; Glaeser, Jessie A.; Maffei, Helen; Smith, Sheri. 2015. Risk and pathway assessment for the introduction of exotic insects and pathogens that could affects Hawai‘i’s native forests. Gen. Tech. Rep. PSW-GTR-250. Albany, CA: U.S. Department of Agriculture, Forest Service, Pacific Southwest Research Station. 171 p.