Erysiphe alphitoides (Griffon & Maublanc) Braun & Takamatsu, 2000

on Quercus

Erysiphe alphitoides on Quercus robur

Quercus robur, Zwanenwater

Erysiphe alphitoides: cleistotheceium on Quercus robur

Quercus robur, Nieuwendam: cleistothecium, hand lens image

Erysiphe alphitoides: cleistotheceium on Quercus robur

cleistothecium

Erysiphe alphitoides: detail of appendage

appendage, tip

Erysiphe alphitoides: ascus

ascus

notes

mycelium conspicuous, mainly epiphyllous, on often disfigured young leaves. Appressoria lobed, sometimes nipple-shaped or multilobed, solitary or paired. Conidia solitary, barrel-shaped, without fibrosin bodies. Cleistothecia mainly epiphyllous, with 4-16 asci that contain 6-8 spores. Generally 10-20 appendages, attached to the equator. They are up to 2 x as long as the diameter, stiff, hyaline, septate, more or less straight; at the tip they are suddenly broadened because they are bifurcated several times in quick succession.

hostplants

Fagaceae, monophagous

Quercus canariensis, castaneifolia, cerris, dalechampii, faginea, frainetto, x hispanica, macanthera, petraea & subsp. iberica, pubescens, pyrenaica, robur, x rosacea, rubra. x streimii.

Rarely on Aesculus hippocastanum; Castanea sativa; Cotinus coggygria; Fagus sylvatica.

Observed in Switzerland on Ailanthus altssima (Simaroubiaceae) (Beenken & Senn-Irlet).

synonyms

Microsphaera alphitoides Griffon & Maublanc, 1912; Oidium quercinum von Thümen, 1878.

Microsphaera gorlenki Fan Tyk Chen, 1975, described from Daphne, possibly concerned a cleistothecium of alphitoides that has been blown by the wind.

notes

During wet and cool summers especially the young foliage of the lammas shoot can be heavily infested. Arrived in Europe around the beginning of the 20th century; the origin is not known. Considered as one of the causative agents of the decline of the oaks in Europe.

references

Abras, Fassotte, Chandelier & Cavelier (2008a), Beenken & Senn-Irlet (2016a), Blumer (1967), Brandenburger (1972a, 1985a: 62), Braun (1995a), Braun & Cook (2102a), Braggion (2013a), Bresinsky (2016a), Czerniawska (2001a), Czerniawska, Madej, Adamska ao (2000a), Doppelbaur (1973a), Dynowska, Fiedorowicz & Kubiak (1999a), Ellis & Ellis (1997a), Jage, Klenke, Kruse ao (2016a), Jage, Klenke & Kummer (2010a), Jage, Kruse, Kummer ao (2013a), Jage, Scholler & Klenke (2010a), Klenke & Scholler (2015a), Korytnianska & Popova (2012a), Kozłowska, Mułenko & Heluta (2015a), Kruse (2014a), Mayor (1967a, 1975a), Mułenko, Piątek, Wołczańska ao (2010a), Ruszkiewicz-Michalska (2006a), Scheuer & Bechter (2012a), Scholler, Reinhard & Schubert (1996a), Sucharzewska (2009a), Sucharzewska, Dynowska, Kubiak ao (2012b), Talgø, Sundheim, Gjærum ao (2010a), Tóth (1994a), Unamuno (1943a).

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mod 25.viii.2018