| Gallery of Pests
- September 2004 -
The dangers of exotic forest pests in North America first became evident when gypsy moth quickly became a problem after its release in 1869 (Howard, 1898). Over the years, hundreds of species of insects and plant pathogens have been introduced to North America (Mattson et al., 1994; Liebhold et al., 1995). Fortunately only a portion of them cause dramatic damage to forests or threaten specific species - while most have relatively low profiles. Below are short summaries for: 1) some of the most serious established exotic pests and pathogens in North American forests, 2) newly discovered pests and pathogens in North America, and 3) pests and pathogens that are not yet here, but which could cause problems if introduced and established. In addition to North America, the Gallery of Pests includes notable entries for U.S. Territories, Possessions, and Protectorates.
How to use the Gallery
You can read the Gallery of Pests by selecting the specific section that interests you from the list below, or you can read the entire Gallery sequentially by using your mouse to squish the emerald ash borer navigational icons at the bottom of each page.
You can also use the table near the bottom of this current page to look up your pest/pathogen by Latin name or by common name.
Regional Pest List
Are you baffled by all the pests in the Gallery, and are you left wondering which pests you should be most worried about? Here is a regional breakdown of the pests threatening the various major geographical regions of the USA.
Section 1 - Pests & pathogens that have not yet arrived or have been eradicated:
Vigilance and prevention can prevent new invasions
Chilean carpenter worm - Chilecomadia valdiviana (Phillippi) (html)
Citrus longhorned beetle - Anoplophora chinensis (Forster) (html)
Eurasian nun moth - Lymantria monacha L. (html)
European oak bark beetle - Scolytus intricatus (Ratzeburg) (html)
European spruce beetle - Ips typographus L. (html)
Pine flat bug - Aradus cinnamomeus Pan (html)
Alder dieback - Phytophthora alni Brasier and Kirk (html) (March 2006)
An unnamed disease - Phytophthora kernoviae Brasier, Beales, and Kirk (html) (March 2006)
Oak dieback - Phytophthora quercina Jung (html) (Added March 2006)
Section 2 - Pests & pathogens not too widely spread:
Early detection and rapid response could be useful to contain or eradicate.
Asian gypsy moth - Lymantria dispar L. (html)
Asian longhorned beetle - Anoplophora glabripennis Motschulsky (html) (Updated August 2008)
Brown longhorned spruce beetle - Tetropium fuscum (Fabricius) (html)
Emerald ash borer - Agrilus planipennis Fairmaire (html) (Updated November 2007)
Laurel wilt & ambrosia beetle - Ophiostoma sp. & Xyleborus glabratus Eichhoff (html) (Added March 2006)
Shot-hole borer - Xyleborus similis Ferrari (html)
Woodwasp-Amylostereum complex - Sirex noctilio F. (html) (Updated October 2007)
Ohi'a rust - Puccinia psidii Winter (html) (Added November 2005)
Section 3 - Pests in significant area, but in a small fraction of total potential range:
Early detection and rapid response could be useful to contain or eradicate locally.
Twig beetle & black walnut disease - Pityophthorus juglandis Blackman & Geosmithia sp. (html) (Added September 2008)
Cactus moth - Cactoblastis cactorum (Bergroth) (html) (Added February 2005)
Erythrina gall wasp - Quadrastichus erythrinae Kim (html) (Added November 2005)
Lobate lac scale - Paratachardina lobata subsp. lobata (Chamberlin) (html) (Added June 2005)
Mediterranean pine engraver beetle - Orthotomicus erosus Wollaston (html) (Updated October 2006)
Red-haired (=golden-haired) pine bark beetle - Hylurgus ligniperda Fabricius (html) (Updated May 2007)
Section 4 - Pests & pathogens that are widespread:
Management of human-assisted vectors still makes sense.
Banded elm bark beetle - Scolytus schevyrewi (Semenov) (html)
Cycad aulacaspis scale - Aulacaspis yasumatsui Takagi (html) (Added October 2005)
Common (or larger) pine shoot beetle - Tomicus piniperda L. (html)
European gypsy moth - Lymatria dispar L. (html)
Hemlock woolly adelgid - Adelges tsugae Annand (html)
Spruce aphid - Elatobium abietinum Walker (html) (Added March 2005)
Dogwood anthracnose disease - Discula destructiva Redl (html)
Port Orford cedar root disease - Phytophthora lateralis (Tucker & Milbrath) (html)
Sudden oak death syndrome - Phytophthora ramorum Werres et al. (html)
Section 5 - Pests & pathogens that are widespread:
Management of vectors no longer makes sense.
An ambrosia beetle - Xylosandrus mutilatus Blandford (html)
An ambrosia beetle - Xylosandrus crassiusculus (Motschulsky) (html)
Balsam woolly adelgid - Adelges piceae (Ratzeburg) (html)
Chestnut gall wasp - Dryocosmus kuriphilus Yasumatsu (html)
Larch casebearer - Coleophora laricella (Huebner) (html)
Beech bark disease - Nectria coccinea var. faginata Lohman, A.M. Watson, and Ayers (html)
Butternut canker - Sirococcus clavigignenti-juglandacearum Nair, Kostichka, & Kuntz (html)
Chestnut blight - Cryphonectria parasitica (Murr.) Barr (html)
Dutch elm disease - Ophiostoma ulmi (Buis.) Narruf. & O. novo-ulmi (Brasier) (html)
European larch canker - Lachnellula willkommii (Hartig) Dennis (html)
Pine pitch canker - Fusarium circinatum Nirenberg and O'Donnell (html)
Phytophthora root rot - Phytophthora cinnamomi Ronds (html)
White pine blister rust - Cronartium ribicola J.C. Fisch. (html)
Much of the material in Faith Campbell's contributions to the Gallery of Pests was previously published in Campbell and Schlarbaum, Fading Forests II: Trading Away North America's Natural Heritage, Published by the Healing Stones Foundation in Cooperation with American Lands Alliance and the University of Tennessee at Knoxville. Copies available from the authors.
The introduction on this page was written by Faith T. Campbell.
The Nature Conservancy's Global Invasive Species Team staff would like to thank in particular the many photographers that contribute to the image archives at http://www.forestryimages.com. Many of their images were used in our presentation. Their specific contributions are noted on our photograph list for animal invaders and pathogens. The forward/backward graphics used in our Gallery pages were adopted from a photograph taken by David Cappaert.
Sources for the introduction on this page
Howard, L. O. 1898. Danger of importing insect pests. 1898. In: Yearbook of the United States Department of Agriculture. 1897. G. M. Hill, Editor. Government Printing Office, Washington. Pp. 529 552.
Liebhold, A. M., W. L. MacDonald, D. Bergdahl, and V. C. Mastro. 1995. Invasion by exotic forest pests: a threat to forest ecosystems. Forest Sci., Monograph 30. 49 pp.
Mattson, W. J., P. Niemela, I. Millers, and Y. Ingauazo. 1994. Immigrant phytophagous insects on woody plants in the United States and Canada: an annotated list. USDA For. Ser. Gen. Tech. Rep. NC-169, 27 pp.
One of the largest collections of photographs of invasive species (mostly plants) available on the web.
An extraordinary database consisting of invasive plant lists, observations, and publications. Look here to learn if a plant has been observed acting as an invader.
Other site resources
Research the information we have on the management of a particular species of invasive animal or pathogen here.
Learn about our 1999 survey--a snapshot of invasive species issues across all of The Nature Conservancy.
A review of remote sensing technology, as applied to invasive species detection and mapping.
Species which are either new to an area, or are showing alarming symptoms such as signs of signicant, new expansion.