Andricus aries (Giraud, 1859)
ramshorn gall wasp
on Quercus, agamous generation
Quercus robur. Dronten, de Zuid, 4.ix.2025 © Arnold Grosscurt: two extreme froms (+ Andricus seminationis)
Quercus robur, Diemer bos, 8.x.2006
basal part of the gall
same, with exit hole
Quercus robur, Dronten, de IJslander, 8.viii.2019 © Arnold Grosscurt: opened gall with pupa
detail
Quercus robur, Zeewolde, Harderbos, 5.vi.2016 © Hans Jonkman: three pictures to show the variability of the gall: from almost no appendages …
… to bearing short appendages …
… to consist of little more than appendages.
3.vii.2016, declining galls
Quercus robur, Zeewolde, Harderbos, 14.viii.2016 © Hans Jonkman; very inconspicuous gall (mid-August)
Quercus robur, Zwolle, Zandhoeve, 6.xi.2020 © Arnold Grosscurt: parasitised gall, section
host plants
Fagaceae, monophagous
Quercus infectoria, petraea, pubescens, robur, vulvanica.
on sexual generation
gall
Although it seems that, at least in NW Europe, the species only has an asexual generation, Walker experimentally has shown that fresh females may deposit eggs in axillary buds of Quercus cerris.
host plants
Fagaceae, monophagous
Quercus cerris.
distribution within Europe
PESI (2024). Originally a species from southeastern Central Europe, but since the start of the 21th century widespread in NW Europe; first record in the Netherlands by Jan-Willem Wertwijn.
references
Azmaz & Katilmiş (2017a), Bayrak (2019a), Bellido, Ros-Farré, Melika & pujade-villar (2003a), Bellmann (2012a), Buhr (1965a), Burton, Ellis & Schneider (2022a), Chinery (2011a), Grosscurt (2025a), Hellrigl (2009a, 2012a), Hellrigl & Bodur (2015a), Houard (1908a), Katılmış & Kıyak (2008a), Kemal & Koçak (2010a), Koops (2013a), Kwast (2012a), Melika (2006a, 2018a), Melika, Csóka & Pujade-Villar (2000a), Redfern & Shirley (2011a), Roskam (2009a), Tomasi (2014a), Walker (2001a), Williams (2010a).