Pest survey card on Entoleuca mammata

This pest survey card was prepared in the context of the EFSA mandate on plant pest surveillance (M-2020-0114), at the request of the European Commission. Its purpose is to guide the Member States in preparing data and information for surveys of the causal agent of hypoxylon canker of quaking aspen (Populus tremuloides Michx) and other poplars (Populus spp.), Entoleuca mammata. These are required to design statistically sound and risk-based pest surveys, in line with current international standards. This pathogen is a well-defined and distinguishable fungal species of the family Xylariaceae and is a protected zone quarantine pest for Ireland and the United Kingdom (Northern Ireland). Entoleuca mammata is reported in Australia, Europe and North America. It is a sapwood pathogen of Populus spp. and infects the host plant through wounds. Symptoms appear on average 2 years after ascospore infection as cankers and unabscissed dead leaves. Entoleuca mammata mainly infects P. tremuloides and P. tremula in North America and Europe, respectively. Other poplar species (and their hybrids) and other broadleaved trees have been reported as hosts of the pathogen. However, there is uncertainty on non-poplar hosts regarding their saprophytic or pathogenic relationship with E. mammata. Detection surveys in the protected zones should focus on P. tremula, while delimiting surveys should be conducted on Populus spp. and hybrids, both native and introduced. Host availability and climatic conditions are not considered to be limiting factors for the establishment and spread of E. mammata in the protected zones for this pest. Wind-borne ascospores are the main source of inoculum, and for infection to occur, exposure of the sapwood via wounds is necessary. Human-assisted spread is facilitated by trade and import of infected plants for planting and wood with bark. The pathogen could also move over long distances on infected but asymptomatic plants, given the 2-year incubation period. Entoleuca mammata can be detected in the field by observation of symptoms on the host plants (unabscissed dead leaves and cankers). Following visual examination, sampling should be conducted if cankers are present. Identification of E. mammata should be confirmed by sequencing the internal transcribed spacer region of rDNA.