Melikaiella tumifica (Osten Sacken, 1865), asexual generation

Material examined: 15 asexual females labelled as “Germany, Baden-Württemberg, Schwetzinger Hardt, 10km SW of Heidelberg, ex acorns on Q. rubra, coll. R. Beiderbeck, 2014.10.01, emerge 2017.03.22”.

Gall. Asexual galls (Fig. 120) are in acorns (Beiderbeck & Nicholls 2014). The acorns are stunted, smaller than a non-infected acorn, and contain up to 6–7 cryptic larval chambers; the cotyledons are brown or used up by the larvae (Beiderbeck & Nicholls 2014).

Biology. See Beiderbeck (2012), Beiderbeck & Nicholls (2014), and Pujade-Villar et al. (2014) for the biology of this species. The sexual generation develops on Q. rubra and Q. velutina; the asexual only known so far from Q. rubra. Sexual generation leaf galls develop in early spring; adults emerge in May-June. Asexual acorn galls were found in October - November, maturing in November. Adults overwinter in galls and emerge in the following spring.

Distribution. USA: New York, Virginia, North Carolina, Illinois, Iowa (Burks 1979). Also an introduced species in Germany (Heidelberg) on introduced Q. rubra (Beiderbeck 2012, Beiderbeck & Nicholls 2014).