Name(s):

Common Spangle Gall

(Neuroterus quercusbaccarum)

and

Silk Button Spangle Gall

(Neuroterus numismalis)

Notes:

These Galls are found on our common Oak (Quercus robur). They are produced by a tiny Cynipid wasp which goes through a rather complicated life cycle using two stages of development.

The process begins in June when a generation of both Male & Female wasps hatch from Currant Galls. The adults mate and the female lays fertilized eggs on the underside of the Oak leaves. These cause the creation of the Common Spangle Gall in which the grub matures. The Spangle Galls fall from the leaves in September and the wasp continues to grow within the leaf litter. In April they hatch to produce a female-only generation. These start the cycle again by laying eggs on Oak flowers which develop into the Currant Galls.

Other species of Cynipid wasps produce different kinds of gall and have different life cycles. One example is the Knopper Gall which uses two different species of Oak (Quercus robur & Quercus cerris) and two years to complete its cycle.

• Link to external site picture of Currant Galls.

Close up of the Silk Button Spangle Gall.

Close up of the Common Spangle Gall.

• If you want to learn how galls are made, visit this link.

• Link back to Pests & Disease Index

© 2001 Chris Skellern. AIE.    Home  | News | A-Z Index  | Resources  |  Contact AIE  |  Terms of Use