Addition to the EPPO Alert List: larch needle brown rust (Triphragmiopsis laricinum)
The Canadian Food Inspection Agency (CFIA) has set up a Plant Health Early Warning System (PHEWS) which is available on Internet. PHEWS provides information on pests which may present phytosanitary risks to Canada. Recently, PHEWS focussed on the larch needle brown rust caused by Triphragmiopsis laricinum.
Triphragmiopsis laricinum (Basidiomycetes: Uredinales) is reported as causing a common and serious needle rust disease in north-eastern China on larch (Larix spp.). It occurs at least in the Provinces of Jilin and Liaoning. Disease incidence can reach 80-100 % in some areas in China. Inoculation experiments showed that all larch species tested were susceptible (Larix gmelinii, L. kaempferi (=L. leptolepis), L. gmelinii var. olgensis (=L. olgensis), L. principis-rupprechtii and L. russica (=L. sibirica). The disease mainly infects seedlings and young trees. It is dispersed by wind and serious attacks usually occur in pure or dense stands in years of frequent rainfall. To control the disease, fungicides can be applied. The use of parasite fungus for biological control is studied in China. Thinning of young stands to increase ventilation and light penetration, and plantation of mixed stands are recommended control measures.
EPPO note: The larch needle brown rust (Triphragmiopsis laricinum) is now added to the EPPO Alert List (see EPPO RS 99/134). Each time a new pest is added by the EPPO Secretariat, the corresponding text (as below) is also added to the complete Alert List available on the EPPO Web site (www.eppo.org).
Triphragmiopsis laricinum - needle brown rust of larch in China
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Why
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Triphragmiopsis laricinum (Basidiomycetes: Uredinales) came to our attention because it is reported in China as a common and serious disease of larch, and the Canadian Food Inspection Agency has noted its possible importance for Canada.
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Where
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China (Jilin, Lioning). More information is needed on its geographical distribution (is it present elsewhere in Asia, e.g. in Japan or Russian Far East?).
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On which plants
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Larch (Larix spp.). In inoculation experiments Larix gmelinii, L. kaempferi (=L. leptolepis), L. gmelinii var. olgensis (=L. olgensis), L. principis-rupprechtii and L. russica (=L. sibirica) were susceptible. No data on the susceptibility of L. decidua (European larch).
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Damage
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High disease incidence is reported in some areas of China (up to 80-100 %), but more detail is needed on the actual damage (growth reduction, mortality?) caused by the disease.
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Pathway
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Plants for planting of Larix species from China, bonsais?
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Possible risks
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Larix are important forest and amenity trees in Europe, and the disease appears to be especially damaging to nurseries and young stands. More data is needed on the biology, severity and geographical distribution of the disease.
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EPPO RS 99/162
Entry date 1999-1
Sources
Canadian Food Inspection Agency - Plant Health Early Warning System. A needle brown rust (fungus) disease of economic importance to larch in northeastern China (submitted by I. MacLatchy, CFIA-PHRA)
http://www.cfia-acia.agr.ca/english/ppc/science/pps/phews/docs/1999/9907larc.html
Shao, L.P.; He, B.Z.; Yang, D.Q.; Qi, X.W. (1983) [Study on the larch brown rust caused by Triphragmiopsis laricinum (Chou) Tai]. Journal of North Eastern Forestry Institute, 11(4), 23-30. (CABI abstract)
Sun, B.G.; Liu, H.Y.; Wang, J.Y. (1983) [Brown rust of Larix and its control]. Forest Science and Technology, Linye Keji Tongxun, no. 7, 28-30. (CABI abstract)
Wang, Y.M.; Liu, G.R.; Wang, S.M.; Tong, Y.; Ren, W.J. (1998) [The economic threshold and forecasting of larch needle brown rust]. Scientia-Silvae-Sinicae, 34(3), 74-79. (CABI abstract)
Yuan, J.Y.; Yuan, Z.W.; Li, L.Z. (1998) [Studies on the biological control of larch brown rust with a rust parasite. 1. Morphological and cultural characteristics of the rust parasite]. Journal of Shenyang Agricultural University, 19(4), 17-22. (CABI abstract)