Acalitus rudis (Canestrini, 1890)
on Betula
Betula pendula, Otterlo, de Zanding; upperside of the leaf © Arnold Grosscurt
underside of the leaf
Betula pendula, Koudhoorn: the hairs of the erineum are “mushroom shaped”.
Betula pendula, Bergen NH, Uilenvanger: gall hairs under the microscope
hostplants
Betulaceae, monophagous
Betula humilis, nana, pendula, pubescens, pumila.
synonyms
Aceria, Eriophyes, rudis. The illustration and description of E. rudis by Houard partly apply to Acalitus calycophthirus.
notes
On galls of this type lives a specialised mildew, Podosphaera erineophila. The causer of the gall itself remains unspecified in the literature (“Erineum betulinum”), but is is worthwile to be alerted on it!
references
Béguinot (2006a, 2007b), Bellmann (2012a), Buhr (1964b), Cogolludo (1921a), Coulianos & Holmåsen (1991a), Dauphin & Aniotsbehere (1997a), Farkas (1965a), Fjelddalen (1995a), Hellrigl (2003a, 2004b), Houard (1908a), Lambinon, Carbonnelle & Claerebout (2015a), Lambinon Schneider & Feitz (2012a), Nalepa (1919a), Redfern & Shirley (2011a), Ripka (2007a), Roivainen (1951a), Roskam (2009a), Skoracka, Lewandowski & Boczek (2005a), Sylvén (1960a), Tomasi (2014a), Vaněčková-Skuhravá (1996a), Wahlgren (1963b), Weidner (1954a).