Aceria nalepai (Fockeu, 1890)
This species may be an inquiline in the galls of Eriophyes inangulis; but it cannot be excluded that the inverse applies, and that it is nalepai that is responsible for the gall.
distribution within Europe
Buhr (1964a) considered A. nalepai an invalid synonym of Eriophyes inangulis Nalepa, 1919. This was incorrect for two reasons. Firstly, nalepai is the senior name, and there is no reason to sink Fockeu’s well-described species as an invalid name. Moreover, it is obvious that Nalepa, while describing his inangulis, was well aware of the existence of nalepai. (He even expressly cited Fockeu’s paper while describing “Eriophyes brevitarsus typicus”). It is true that he made no reference to nalepai, but this may be understood because he limited the scope of his paper to Eriophyes species, while nalepai originally was described in Phytoptus.
For Nalepa nalepai and inangulis were two valid species. So long no modern revision of the Eriophyidae on alder is available, it seems best to accept that as the status quo. The most probable explanation of two mites associated with one gall type is that one species is an inquiline of the other.
The original illustration of “Phytoptus nalepai” in Fockeu’s publication.
Aceria nalepai Trouessart, 1891 is a junior, therefore invalid, homonym; it is a synonym of Aceria hippophaena.
Blanes-Dalmau, Caballero-López & Pujade-Villar (2017a), Buhr (1964a), Davis, Flechtmann, Boczek & Barké (1982a), Fockeu (1890a), Hellrigl (2003a), Lehmann & Flügel (2012a), Redfern & Shirley (2011a), Skoracka, Lewandowski & Boczek (2005a), Stefănescu (2009a), Tomasi (2003a).