Skip to Main Content
Geosmithia morbida, the causal agent of thousand cankers disease, found in IndianaAuthor(s): Matthew Ginzel; Jennifer Juzwik
Source: HN-89-W. West Lafayette, IN: Purdue Extension, Department of Entomology. 2 p.
Publication Series: Miscellaneous Publication
Station: Northern Research Station
PDF: Download Publication (184.19 KB)
DescriptionThousand Cankers Disease (TCD) is caused by a fungus (Geosmithia morbida) that is vectored by a bark beetle, the walnut twig beetle (WTB), Pityophthorus juglandis (Coleoptera: Curculionidae: Scolytinae). The disease was first recognized in 2008 and has caused the widespread death of walnut trees (Juglans sp.) throughout eight western states. As the beetle bores into a walnut tree to feed and reproduce, it infects the bark tissue with the fungal pathogen. G. morbida is considered a weak plant pathogen and requires a vector to become established. It appears that only mass attack by the beetle is sufficient to introduce enough pathogen to kill a tree. In the early stages of TCD, small cankers develop around the galleries of colonizing beetles. As the disease progresses, cankers become more diffuse and coalesce, interrupting the nutrient-conducting tissues of the tree and eventually killing the inner bark of affected branches and stems.
- Check the Northern Research Station web site to request a printed copy of this publication.
- Our on-line publications are scanned and captured using Adobe Acrobat.
- During the capture process some typographical errors may occur.
- Please contact Sharon Hobrla, email@example.com if you notice any errors which make this publication unusable.
- We recommend that you also print this page and attach it to the printout of the article, to retain the full citation information.
- This article was written and prepared by U.S. Government employees on official time, and is therefore in the public domain.
CitationGinzel, Matthew; Juzwik, Jennifer. 2014. Geosmithia morbida, the causal agent of thousand cankers disease, found in Indiana. HN-89-W. West Lafayette, IN: Purdue Extension, Department of Entomology. 2 p.
- Bark and ambrosia beetles and their associated fungi colonizing stressed walnut in Missouri and Indiana
- Colonization of artificially stressed black walnut trees by ambrosia beetle, bark beetle, and other weevil species (Coleoptera: Curculionidae) in Indiana and Missouri
- Chapter 8 - Assessment and etiology of thousand cankers disease within the native range of black walnut (Juglans nigra)
XML: View XML