Photograph of Thomas Harrington

Dr. Thomas C Harrington

  • Professor


Social Media and Websites

Area of Expertise

  • Plant Pathology


  • B.S., Plant Pathology, Colorado State University, 1977
  • M.S., Plant Pathology, Washington State University, 1980
  • Ph.D., Plant Pathology, University of California at Berkeley, 1983

Dr. Harrington was on the faculty of the University of New Hampshire from 1983 through 1990 as an Assistant Professor, Associate Professor and Chair of Botany and Plant Pathology. He has been a member of the ISU Plant Pathology Department since 1991 and has had a joint appointment in the Forestry Faculty since 1996.


Dr. Harrington's research focuses on pathogens in forest trees. Most of these studies involve the genetics, evolution or taxonomy of fungi and their populations on forest trees. A new bacterial disease of ash, fungi on poplars, fungi associated with bark beetles, the genus Ceratocystis, and root and butt rot fungi (Armillaria and Heterobasidion) are specialties. Dr. Harrington is also a member of the Interdepartmental Genetics Major faculty and the Ecology and Evolutionary Biology Major faculty.


  • Worrall, J. J., T. D. Lee, and T. C. Harrington. Forest dynamics and agents that initiate and expand canopy gaps in Picea-Abies forests of Crawford Notch, New Hampshire, USA. J. Ecology (in press)
  • Harrington, T. C. 2004. Ecology and evolution of mycophagous bark beetles and their fungal partners. In: Ecological and Evolutionary Advances in Insect-Fungal Associations, F. E. Vega and M. Blackwell, eds. Oxford University Press. (in press).
  • Blanchette, R. A., W. H. Benjamin, J. A. Jurgens, D. L. McNew, T. C. Harrington, S. Duncan, and R. L. Farrell. 2004. Wood destroying soft-rot fungi in the historic expedition huts of Antarctica. Appl. Environ. Microbiol. 70:1328-1335.
  • Worrall, J., K. Sullivan, T.C. Harrington, and J. Steimel. 2004. Incidence, host relations and population structure of Armillaria ostoyae in Colorado campgrounds. Forest Ecology and Management 192:191-206.
  • Engelbrecht, C. J. B., T. C. Harrington, J. Steimel, and P. Capretti. Genetic variation in eastern North American and putatively introduced populations of Ceratocystis fimbriata f. platani. Molecular Ecology 13:2995-3005.
  • Zauza, E.A.V., A.C Alfenas, T.C Harrington, E.S Mizubuti, and J.F Silva. 2004. Resistance of Eucalyptus clones to Ceratocystis fimbriata. Plant Dis. 88:758-760.
  • Maijala, P., T. C. Harrington, and M. Raudaskoski. 2003. A peroxidase gene family and gene trees in Heterobasidion and related genera. Mycologia 95:209-221.
  • Hsiau, P. T., and T. C. Harrington. 2003. Phylogenetics and adaptations of basidiomycetous fungi fed upon by bark beetles (Coleoptera: Scolytidae). Symbiosis 34:111-131.
  • Harrington, T. C. and D. L. McNew. 2003. Phylogenetic analysis places the phialophora-like anamorph genus Cadophora in the Helotiales. Mycotaxon 87:141-151.
  • de Beer, Z. W., T. C. Harrington, H. F. Vismer, B. D. Wingfield, and M. J. Wingfield. 2003. Phylogeny of the Ophiostoma stenoceras - Sporothrix schenckii complex. Mycologia 95:434-441.
  • Baker, C. J., T. C. Harrington, U. Krauss, and A. Alfenas. 2003. Genetic variability and host specialization within the Latin American clade of Ceratocystis fimbriata. Phytopathology 93:1274-1284.
  • Six, D. L., T. C. Harrington, J. Steimel, D. McNew, and T. D. Paine. 2003. Genetic relationships among Leptographium terebrantis and the mycangial fungi of three western Dendroctonus bark beetles. Mycologia 95:781-792.
  • Paulin-Mahady, A. E., T. C. Harrington, and D. McNew. 2002. Phylogenetic and taxonomic evaluation of Chalara, Chalaropsis, and Thielaviopsis anamorphs associated with Ceratocystis. Mycologia 94:62-72.
  • Harrington, T. C., N. V. Pashenova, D. L. McNew, J. Steimel, and M. Y. Konstantinov. 2002. Species delimitation and host specialization of Ceratocystis laricicola and C. polonica to larch and spruce. Plant Dis. 86:418-422.
  • Coetzee, M. P. A., B. D. Wingfield, T. C. Harrington, J. Steimel, T. A. Coutinho, and M.J. Wingfield. 2001. The root rot fungus Armillaria mellea introduced into South Africa by early Dutch settlers. Molecular Ecology 10:387-396.
  • Feeley, C. J., E. R. Hart, J. R. Thompson, and T. C. Harrington. 2001. Occurrence, associated symptoms, and potential insect vectors of the ash yellows phytoplasma in Iowa. J. Arboriculture 27:331-339.
  • Roux, J., T. C. Harrington, J. P. Steimel, and M. J. Wingfield. 2001. Genetic variation in the wilt pathogen Ceratocystis albofundus. Mycoscience 42: 327-332.
  • Coetzee, M. P. A., B. D. Wingfield, T. C. Harrington, D. Dalevi, T. A. Coutinho, and M. J. Wingfield. 2000. Geographic diversity of Armillaria mellea s. s. based on phylogenetic analysis. Mycologia 92:105-113.
  • Rojas, M. G., J. A. Morales-Ramos, and T. C. Harrington. 1999. Association between Hpothenemus hampei (Coleoptera: Scolytidae) and Fusarium solani (Moniliales: Tuberculariaceae). Ann. Entomol. Soc. Am. 92:98-100.
  • Witthuhn, R. C., B. D. Wingfield, M. J. Wingfield, and T. C. Harrington. 1999. PCR-based identification and phylogeny of species of Ceratocystis sensu stricto. Mycol. Res. 103:743-749.
  • Harrington, T. C., and D. M. Rizzo. 1999. Defining species in the fungi. pages 43-71 In: J. J. Worrall, ed., Structure and Dynamics of Fungal Populations. Kluwer Press. Dordrecht, The Netherlands.
  • Laia, M. L., A. C. Alfenas, and T. C. Harrington. 1999. Isolation, detection in soil, and inoculation of Ceratocystis fimbriata, causal agent of wilting, die-back and canker in Eucalyptus. page 77 In: Proc. 12th Biennial Conf. of the Australian Plant Pathology Soc., Canberra, September 1999.
  • Witthuhn, R. C., B. D. Wingfield, M. J. Wingfield, M. Wolfaardt, and T. C. Harrington. 1998. Monophyly of the conifer species in the Ceratocystis coerulescens complex using DNA sequence data. Mycologia 90:96-100.
  • Harrington, T. C., and D. L. McNew. 1998. Partial interfertility among the Ceratocystis species on conifers. Fung. Gen. Biol. 25:44-53.
  • Harrington, T. C., and M. J. Wingfield. 1998. The Ceratocystis species on conifers. Can. J. Bot. 76:1446-1457.
  • Harrington, T. C., and M. J. Wingfield. 1998. Diseases and the ecology of indigenous and exotic pines. pp. 381-404 In: D. Richardson, ed. Ecology and Biogeography of Pinus. Cambridge University Press.
  • Harrington, T. C., J. Steimel, and G. A. Kile. 1998. Genetic variation in three Ceratocystis species with outcrossing, selfing and asexual reproductive strategies. Eur. J. For. Pathol. 28:217-226.
  • Maijala, P., T. C. Harrington, and M. Raudaskoski. 1998. Peroxidase gene structure and gene trees in Heterobasidion. pages 62-70 In: L.J.L.D. Van Griensven & J. Visser (eds): Proceedings of the Fourth Meeting on the Genetics and Cellular Biology of Basidiomycetes, The Netherlands.
  • Harrington, T. C., D. M. Rizzo, R. A. DeScenzo, and J. Steimel. 1998. Genetic relationships among clones of Heterobasidion annosum in a pine forest. In: C. Delatour, J. J. Guillaumin, B. Lung-Escarmant, and B. Marcais, eds., Root and Butt Rots of Forest Trees. 9th Intern. Conf. on Root and Butt Rots, INRA Editions (France), Les Colloques 89:159-170.
  • Harrington, T. C., J. Stenlid, and K. Korhonen. 1998. Evolution in the genus Heterobasidion. In: C. Delatour, J. J. Guillaumin, B. Lung-Escarmant, and B. Marcais, eds., Root and Butt Rots of Forest Trees. 9th Intern. Conf. on Root and Butt Rots, INRA Editions (France), Les Colloques 89:63-74.
  • Farrell, R. L., E. Hadar, S. J. Kay, R. A. Blanchette, and T. C. Harrington. 1998. Survey of sapstain organisms in New Zealand and albino anti-sapstain fungi. pp. 57-62 In: Biology and Prevention of Sapstain, Publ. 7273, Forest Products Society, Madison, Wisc.