Andricus seminationis (Giraud, 1859)

on Quercus

Quercus robur, Biddinghuizen, Spijkbos, 15.v.2021 © Arnold Grosscurt

Quercus robur, Belgium, prov. Antwerp, Meerhout, Keyfheide, 9.v.2015 © Carina Van Steenwinkel: the axis of the inflorescence is swollen and malformed, but the galls are yet to appear

Quercus robur, Belgium, prov. Limbourg, Maasmechelen, 12.v.2018 © Carina Van Steenwinkel: young galls

Quercus robur, Belgium, prov. Antwerp, Meerhout, Keyfheide, 9..v.2015 © Carina Van Steenwinkel: older galls – unstalked, presumably parasitised

Quercus robur, Belgium, prov. Antwerp, Balen, Scheps, 7.vi.2015 © Carina Van Steenwinkel: mature galls

detail

Quercus spec., Belgium, prov. Limbourg, Nieuwerkerken, Schelfheide, 12.x.2019 © Carina Van Steenwinkel: old (date!), parasitised gall

Quercus robur, Loenen (Gld), 1.vi.2017 © Arnold Grosscurt: older gall

another specimen

leaf gall (from Houard, 1908a)

gall

Catkin gall, rarely leaf gall. Generally the gall is preceded by a strong, often angular swelling of the axis of the catkin. Days later the gall itself appears. The fresh gall is green, slender fusiform, 6-8 mm long, ribbed lengthwise. The young gall has short but obvious, downwards directed hairs, that later disappear. The gall stands on a stalk of c. 5 mm (except when parasitised). Often several galls in a male catkin. As a leaf gall the gall is attached to the leaf margin. Galls in May-June; the wasps emerge in the spring of the second year.

hostplants

Fagaceae, monophagous

Quercus petraea, pubescens, robur.

notes

Only the agamous generation is known.

references

Béguinot (2003a), Bellmann (2012a), Buhr (1965a), Burton, Ellis & Schneider (2022a), Chinery (2011a), Dauphin & Aniotsbehere (1997a), Eady & Quinlan (1963a), Hellrigl (2009a), Hellrigl & Bodur (2015a), Houard (1908a), Koops (2013a), Kwast (2012a, 2014a), Lambinon, Schneider & Chevin (2003a), Meika (2006a), Melika, Csóka & Pujade-Villar (2000a), Redfern & Shirley (2011a), Roskam (2009a), Tomasi (2014a), Wiebes-Rijks (1976a), Williams (2010a).