Melikaiella tumifica (Osten Sacken) comb. n.

Cynips tumifica
Andricus tumificus
Callirhytis tumifica

Only the sexual generation is known to induce swelling-like galls on the midrib of the leaves on red oaks (Q. rubra and Q. velutina), distributed in several states of USA. Most of the galls are near the basis of the leaf, but sometime also on the petiole. Larval chambers are arranged in rows. Galls occur in spring, adults emerge in May and June.

Distribution. USA (New York, Virginia, North Carolina, Illinois, and Iowa).

Callirhytis tumifica

Quercus coccinea, rubra, velutina
Leaf galls, integral
Fig 255. Midrib swelling at base of leaf blade or on petiole, many-celled, green, in May-June.

[Photo caption]

255. On Q rubra. Also on Q coccinea, velutina. Adults were emerging June 15 (IL).; July (VA).

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. Sexual generation gall (Fig. 119) is a large, multilocular thickening of the leaf midrib/petiole.

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).