Red-pea Gall - Cynips divisa f. agamic
Cynips divisa is a Cynipid gall wasp that causes galls to form on Pedunculate and Sessile Oak. These galls are more likely to be seen than the adult wasps.
The Red Pea Gall is caused by the agamic generation on the underside of the Oak leaves. The point of attachment may show as an indistinct spot on the leaf upperside. It is spherical, up to 6mm diameter, has a smooth surface, and is hard (not succulent). The gall is thick-walled and hard to crush, with a circular chamber inside.
The gall can be similar to those caused by other species such as Neuroterus anthracinus, Cynips longiventris and Cynips quercusfolii.
When recording the gall please provide good close ups (a side-on view), and an indication of size. It is helpful to section the gall to look at inner structure.
Check for the presence of tissue flaps, or 'saddle' to eliminate Neuroterus anthracinus.
English/Sessile oaks
See British Plant Galls (Redfern and Shirley 2023).
sue
Botcheston
24 July 2025 on host Quercus robur Old Fosse Sapcote 4985 9222 (taken 3.8.2006)_gall.JPG)
Graham Calow
Sapcote
03 August 2006
Graham Calow
Sapcote B4114 Coventry Road
20 September 2021
agamous generation gall on Oak
Graham Calow
Sapcote B4114 Coventry Road
20 September 2021
gall with thick wall
Melinda Bell
Heather,QEDJWood
17 September 2023
agamic galls
sue
Heather, Swepstone Rd, plantation opposite Cattows
16 August 2024
on oak
sue
Staunton Harold, by lake
13 June 2025
Melinda Bell
Heather,QEDJWood
17 September 2023
thick walls
 on host Quercus robur Old Fosse Sapcote 4985 9222 (taken 3.8.2006)_gall.JPG)
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Species profile
- Common names
- Red-pea Gall Causer
- Species group:
- insect - hymenopteran
- Kingdom:
- Animalia
- Order:
- Hymenoptera
- Family:
- Cynipidae
- Records on NatureSpot:
- 30
- First record:
- 03/08/2006 (Calow, Graham)
- Last record:
- 14/08/2025 (Timms, Sue)
Total records by month
% of records within its species group
10km squares with records
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Latest images
Latest records
Kaye Axon
Enderby, Mill Lane
14 August 2024
Craig Mabbett
Bosworth Road Walton
25 October 2015
sue
Newbold Verdon, Dragon Lane recreation ground
05 November 2023
Melinda Bell
Heather,QEDJWood
17 September 2023
6mm diameter
sue
Ratby Burroughs
31 July 2024
