This month sees the publication of map number 1000 of Distribution Maps of Plant Diseases the authoritative source for accurate data on the worldwide distribution of plant diseases of economic or quarantine importance, published by CABI in association with the European and Mediterranean Plant Protection Organization (EPPO).

First published in 1942, Distribution Maps of Plant Diseases are a respected, referenced source of distribution data, expertly compiled and validated and used by plant health organisations around the world. The maps cover important diseases affecting agriculture, horticulture and forestry. Two sets of 18 disease maps are produced each year, covering fungi, bacteria, viruses and nematodes, comprising mostly of new maps and also some map revisions. Many maps have been revised following changes to taxonomy or distribution, some a number of times – the most revised map is currently Peronospora hyoscyami f.sp. tabacina (map no. 23) which was revised for the 10th time in 1998!

Since April 2006 Distribution Maps of Plant Diseases as well as it’s sister product Distribution Maps of Plant Pests (with maps of nearly 700 arthropod plant pest species) have also been available in electronic format with a complete and fully searchable electronic backfile dating back over the 65 years of their publication.

And the 1000th disease species to be mapped is… (drum roll please)… Oidium neolycopersici L. Kiss, a fungus commonly known as tomato powdery mildew affecting the leaves and stems of, as the name suggests, mainly tomato (Lycopersicon esculentum). Severe infections caused by O. neolycopersici, especially if they start early in the growing season, lead to a reduction in fruit size and quality. Apparently, it was absent in Canada and the USA until the 1990s but soon after its first detection on greenhouse tomatoes in Québec, Canada the pathogen spread rapidly from one region to another in North America and it is now widespread in many states of Canada and the USA. This indicates that the fungus can be considered as an invasive species as it can spread rapidly in new areas where it sometimes causes economic damage. O. neolycopersici was only recently recognized as a distinct species of the Erysiphaceae during studies by Kiss et al. (see references below) and this recent clarification has enabled us to accurately map this species now.

To celebrate the publication of map no. 1000 we have made this map open access – just click here to view it in PDF format.

For more information about this product including the processes involved in making the maps, how to get a free trial or subscribe and for a full list of the species that are mapped in Distribution Maps of Plant Diseases please go to

For more information on Oidium neolycopersici and its distribution please see the following references:

  • Kiss, L.; Cook, R. T. A.; Saenz, G. S.; Cunnington, J. H.; Takamatsu, S.; Pascoe, I.; Bardin, M.; Nicot, P. C.; Sato, Y.; Rossman, A. Y. (2001) Identification of two powdery mildew fungi, Oidium neolycopersici sp. nov. and O. lycopersici, infecting tomato in different parts of the world. Mycological Research 105 (6), 684-697.
  • Kiss, L.; Takamatsu, S.; Cunnington, J. H. (2005) Molecular identification of Oidium neolycopersici as the causal agent of the recent tomato powdery mildew epidemics in North America. Plant Disease 89, 491-496.
  • CABI (2006) Crop Protection Compendium.

1 Comment

  1. common Japanese words on 17th March 2009 at 2:57 pm

    With 1000s and 1000s of diseases it is amazing that anything survives.

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