EPPO Global Database

Melampsora medusae(MELMME)

Distribution details in United States of America

Situation
Current pest situation evaluated by EPPO on the basis of information dated 2018: Present, widespread
From CABI Disease map 547 (1991): Present, widespread
From NPPO: Present, widespread
Comments
Widespread, but most important in New England and the Lake States.

EPPO Reporting Service (1993/52) , first outbreaks on poplar hybrids in northwest (Washington).

EPPO Reporting Service (2000/163) : these have since been shown to be caused by a natural hybrid between M. medusae, which is not found as such in the Pacific Northwest, and the local M. occidentalis (which is non-pathogenic to hybrid poplars). This is known as M. x columbiana.

EPPO Reporting Service (2019/049) : found on Populus mexicana subsp. dimorpha in Gainesville.

References
* INTERNET
Widely Prevalent Fungi of the United States. https://www.prevalentfungi.org

* Lloyd AL, Smith JA (2018) First report of poplar leaf rust caused by Melampsora medusae on Populus mexicana in the United States. Plant Disease 102(10), 2031-2033.
------- On Populus mexicana subsp. dimorpha in Gainesville (Florida).

* Newcombe, G.; Stirling, B.; McDonald, S.; Bradshaw jr, H.D. (2000) Melampsora x columbiana, a natural hybrid of M. medusae and M. occidentalis. Mycological Research, 104(3), 261-274.

* Prakash, C. S.; Thielges, B. A. (1989) Canadian Journal of Botany 67 (2), 486-490.
------- 12 isloates from 6 locations across eastern USA were tested for their reaction on 18 Populus genotypes. All isolates were recognised as distinct physiologic races.

* Widin, K. D.; Schipper, A. L., Jr. (1981) Effect of Melampsora medusae leaf rust infection on yield of hybrid poplars in the north-central United States. European Journal of Forest Pathology 11 (7), 438-448.
------- Yield losses in north-central USA were most severe within the natural range of the alternate host Larix.
Situation in neighbouring countries
Country State Status
Canada British Columbia Present, no details view...
Canada Newfoundland Present, no details view...
Canada Nova Scotia Present, no details view...
Canada Prince Edward Island Present, no details view...
Canada Québec Present, no details view...
Canada Northwest Territories Present, no details view...
Canada Ontario Present, no details view...
Canada Manitoba Present, no details view...
Canada Present, widespread view...
Canada Saskatchewan Present, no details view...
Canada Alberta Present, no details view...
Canada New Brunswick Present, no details view...
Mexico Present, restricted distribution view...