Andricus hartigi (Hartig, 1843)
on Quercus

Quercus robur gall, with at right a schematic transverse section (from Houard, 1908a)

Quercus pubescens, France, leg Benoît Huc © Sébastien Carbonnelle
gall
Gall derives from a dormant bud on the stem or the underside of a thick branch. The gall itself is unilocular, rotund and pea-sized. However, it is completely hidden by some 30 processes, each consisting of a narrow stalk, followed by a broad cone that ends in a slender curved spine. The gall therefore has the appearance of a heavily spinose walnut.
hostplants
Fagaceae, monophagous
Quercus frainetto, petraea, pubescens, pyrenaica, robur.
synonyms
Cynips hartigi.
notes
The sexual generation could be Andricus cydoniae (Stone ao, 2008a).
references
Buhr (1965a), Hellrigl (2009a), Hellrigl & Bodur (2015a), Houard (1908a), Katılmış & Kıyak (2008a), Kemal & Koçak (2010a), Marković (2014a, 2015a), Melika (2006a), Melika, Csóka & Pujade-Villar (2000a), Pellizzari (2010a), Shachar, Melika, Inbar & Dorchin (2018a), Stone, Atkinson, Rokas ao (2008a), Tomasi (2014a).