Taxonomic information	Current valid scientific name: Entoleuca mammata Synonyms: Anthostoma blakei, Anthostoma morsei, Fuckelia morsei, Hypoxylon blakei, Hypoxylon holwayi, Hypoxylon mammatum, Hypoxylon morsei, Hypoxylon pauperatum, Hypoxylon pruinatum, Nemania mammata, Rosellinia pruinata, Sphaeria mammata, Sphaeria pruinata (according to Index Fungorum, 2024) Name used in the EU legislation: Entoleuca mammata (Wahlenb.) Rogers and Ju Order: Xylariales Family: Xylariaceae Common name: Hypoxylon canker of poplar, canker of poplar, canker of aspen Name used in the Dossier: Entoleuca mammata Note: For an extensive review on taxonomy of the genera Nemania, Hypoxylon and Entoleuca, see Granmo et al. (1999)
Group	Fungi
EPPO code	HYPOMA
Regulated status	Entoleuca mammata is listed in Annex III of Commission Implementing Regulation (EU) 2019/2072 as protected zone quarantine pest for Ireland. The pathogen is quarantine pest in China and Israel. It is on the A1 list of Türkiye (EPPO, 2024a).
Pest status in the UK	E. mammata is present in the UK, with few occurrences in England, Wales, Channel Islands and Scotland (CABI, 2019; EPPO, 2024b; Mathiassen, 1993).
Pest status in the EU	E. mammata is reported from the following EU MS: Austria, Belgium, Croatia, Czechia, Finland, France, Germany, Greece, Italy, Lithuania, the Netherlands, Slovakia, Slovenia, Sweden (EFSA PLH Panel, 2017), Denmark (GBIF, 2024), Estonia (Lutter et al., 2019), Latvia (Zeps et al., 2016); Poland and Spain (Farr & Rossman, 2024).
Host status on Betula pendula and Betula pubescens	E. mammata was reported on Betula pubescens in Finland (Granmo et al., 1999) and on Betula pendula (Betula alba) in Sweden (Mathiassen, 1993). E. mammata is reported as a pathogen of Betula alleghaniensis (synonym: Betula lutea), Betula papyrifera (Conners, 1967; Ginns, 1986) and Betula sp. (EPPO, 2024c; Ginns, 1986).
PRA information	Pest Risk Assessments available: –Pest categorisation of Entoleuca mammata (EFSA PLH Panel, 2017); –Express Pest Risk Analysis: Entoleuca mammata (Klejdysz et al., 2018); –UK Risk Register Details for Entoleuca mammata (DEFRA, 2023).
Other relevant information for the assessment
Biology	E. mammata is an ascomycete fungus mostly known as pathogen causing canker disease in Populus tremuloides and P. tremula (EFSA PLH Panel, 2017), as well as primary saprophyte on several Salix species (Mathiassen, 1993). The fungus was firstly described as Sphaeria mammata on Betula alba (current name: B. pendula) from Swedish Lapland in 1826 (Mathiassen, 1993), but it is thought to be native to North America and introduced into Europe several centuries ago (Kasanen et al., 2004). E. mammata is now largely distributed in the temperate zones of the northern hemisphere; it is present in Canada and in several states of the USA (CABI, 2019; EPPO, 2024b). In Asia, E. mammata is only found in the Korea Republic on decayed wood (Lee et al., 2000). In Europe, in addition to the mentioned EU MS and the UK (see above), it is reported from Andorra, Russia, Serbia, Switzerland, Ukraine (CABI, 2019; EPPO, 2024b) and Norway (Granmo et al., 1999; NBIC, 2021). The presence of E. mammata in Australia is uncertain (few specimens in herbarium without other records) (EPPO, 2024b). The ascospores of E. mammata infect the living wood penetrating in the periderm and invading tissues under bark through mechanical wounds and injuries caused by woodpeckers and insects (Anderson et al., 1979a; Ostry & Anderson, 1983); water stress can increase host susceptibility (EFSA PLH Panel, 2017). E. mammata overwinters in host tissues both as mycelium and spores. Five to 14 months after infection conidia are produced, but their role in the disease transmission is not relevant (EFSA PLH Panel, 2017). The pathogen is mostly found on trees 15–40 years‐old, but all ages can be infected (EFSA PLH Panel, 2017; EPPO 2024d). Infection usually starts from branches and twigs and then spreads to the main stem. E. mammata is most frequently found on stems about 1.5–2.5 m above the ground (Mathiassen, 1993). The cankers expand very rapidly (7–8 cm per month) in summer, and more slowly during winter; branches and stems can be girdled causing drying and breakage. The fungus mostly develops in the range from 8°C to 32°C, the optimum temperature is 28°C; toxins host‐specific produced by the fungus are involved in pathogenesis (EFSA PLH Panel, 2017; EPPO, 2023; Stermer et al., 1984). E. mammata can spread over long distances via windborne ascospores, which are produced 2–3 years after infection; cankers on felled trees on the ground continue to produce ascospores for 23 months. Ascospores are dispersed with a temperature above −4°C and wet weather; a minimum of 16°C is required for starting germination, which became rapid at 28–32°C (EFSA PLH Panel, 2017). Infected wood, mostly with bark, may be a pathway for passive spread of E. mammata in international trade; however, also young plants may carry ascospores or mycelium of the fungus, which can survive as a latent infection on living material inadvertently moved (EFSA PLH Panel, 2017; EPPO, 2023). E. mammata is an important pathogen of poplars in the USA and Canada, causing economic losses of millions of dollars a year (Anderson et al., 1979b; EFSA PLH Panel, 2017; Ostry, 2013). In Europe E. mammata is known as a pest of low importance, although damage on Populus tremula has been reported in France (Pinon, 1976) and Italy (EFSA PLH Panel, 2017) and in poplar plantations in Sweden and Estonia (EFSA PLH Panel, 2017; Lutter et al., 2019). Data on the incidence and impact of E. mammata on woody species other than poplars and willows are poor or absent, and may be considered negligible; on Betula, the fungus only occurs on ‘very deteriorated wood’ (Granmo et al., 1999).
Symptoms	Main type of symptoms	There is no information on the symptoms caused to Betula plants. However, the symptoms are generic and they are described for Populus trees. Early symptoms of cankers on the bark appear as slightly sunken, yellowish‐orange areas with an irregular border. Young cankers can be identified by removing the bark to expose the white mycelium in the cambial zone. The outer bark in older cankers is then lifted into blister‐like patches and break away, exposing blackened areas prominently visible on green branches and trunks. Callus formation only occasionally develops because cankers spread very quickly (Anderson et al., 1979b; EPPO, 2023). Wilting of leaves may be observed when living trees are girdled by cankers, as well as sprouting of new shoots on stem and branches. Infected trees can be secondarily colonised by other fungi, accelerating the host decline (EPPO, 2023).
	Presence of asymptomatic plants	On poplar, the disease caused by E. mammata has a latent period and symptoms can appear only 2 years after the ascospore infection, therefore asymptomatic plants can be found (Ostry & Anderson, 2009).
	Confusion with other pests	Some Hypoxylon species present in Europe on deciduous trees (H. confluens and H. udum) show symptoms similar to those of E. mammata but can be easily distinguished in laboratory by the ascospore characteristics (EFSA PLH Panel, 2017). According to Granmo et al. (1999), E. mammata is also easily distinguished from species of Nemania by its oligoperitheciate erumpent stromata and polygonal perithecial demarcations.
Host plant range	In North America, E. mammata mainly infects P. tremuloides. Minor damage is recorded on P. alleghaniensis, P. balsamifera, P. grandidentata and various Populus hybrids. Other secondary hosts in North America are Acer, Alnus, Betula, Carpinus, Fagus, Picea, Pyrus, Salix, Sorbus and Ulmus (Manion & Griffin, 1986). In Europe, the main hosts are poplars, mostly P. tremula. Other hosts are P. alba, P. nigra, P. trichocarpa and the hybrid P. tremula × P. tremuloides (Ostry, 2013). However, in the central and northern Scandinava willows seem to be the main hosts of E. mammata, mostly Salix caprea, S. pentandra and S. myrsinifolia. The fungus is here also found on Populus and Sorbus, whereas Betula is considered only a secondary host (Mathiassen, 1993). In the long list of specimens examined by Granmo et al. (1999) just one record of Betula pubescens as host of E. mammata is reported. In the UK, E. mammata has been reported on Salix in Wales (Mathiassen, 1993). Betula alleghaniensis (synonym: Betula lutea), Betula papyrifera are also hosts of E. mammata according to Conners (1967), Ginns (1986) and Granmo et al. (1999).
Reported evidence of impact	E. mammata is an EU protected zone quarantine pest.
Evidence that the commodity is a pathway	Plants for planting may carry ascospores and mycelium of E. mammata also asymptomatically (EFSA PLH Panel, 2017; EPPO 2024d), therefore the commodity is a pathway. E. mammata is believed to have been introduced at least once in the last century into France with plant material (flowering branches of Populus tremula) used for hybridisation (EPPO, 2024d).
Surveillance information	E. mammata is not a regulated pest for the UK and it is not under official control and surveillance. However, Great Britain exports to Northern Ireland are required to be free from E. mammata to ensure Northern Ireland remains a pest free protected zone (Dossier Section 5.1).