Phytoptus tetratrichus (Nalepa, 1890)
Tilia tomentosa, Schiedam © Ben van As
Tilia tomentosa, France, Rhône-Alpes, Haute-Savoie, Saint-Gervais-les-Bains; © Arnold Grosscurt
underside of the leaf
reddish brown spots at the underside of the leaf correspond with erinea at the upperside
Tilia tomentosa, Hollandsche Rading: upper side
Tilia sp., Germany, Bavaria, Lengfurt am Main; © Arnold Grosscurt
Only the deuterogyne stage causes galls, that differ according to the hostplant: narrow rolls of the leaf margin in Tilia cordata and cordata x americana, small wart-like galls at the upper surface, and small round erinea at the underside of the leaf in T. tomentosa, irregular finger-like galls at either side of the leaf in T. americana.
Tilia americana, cordata, x flavescens, tomentosa.
Explicitely not mentioned from T, platypyhllos by Soika.
Uppersurface, wart-like galls, at the underside covered by an erineum, are attributed to Phytoptus abnormis Garman, 1883 in the Dutch cecidological literature, to Ph. erinotes (Nalepa, 1918) by the British. Probably this is incorrect, and must these galls too be attributed to tetratrichus.
Béguinot (2007b), Buhr (1965a), Chinery (2011a), Dauphin & Aniotsbehre (1997a), Farkas (1965a), Hellrigl (2006a, 2010a), Jočić & Petanović (2012a), Kielkiewicz, Soika & Olszewska-Kaczynska (2011a), Kollár (2007a, 2011a), Koops (2013a), Lambinon Schneider & Feitz (2012a), Lehmann & Flügel (2012a), Petanović (1998a), Petanović & Stanković (1999a), Redfern & Shirley (2011a), Ripka (2007a), Roivainen (1947a), Roskam (2009a), Skoracka, Lewandowski & Boczek (2005a), Soika (2006a), Soika & Kozak (2011a, 2012a), Sylvén (1960a), Tomasi (2014a), Weidner (1954a).