Red Pea Gall Wasp - Cynips divisa
Cynips divisa is a Cynipid gall wasp that causes Pea Galls to form on Pendunculate and Sessile Oak. A Red Wart Gall is the sexual generation gall and can be found in axillary or terminal buds on the twig, and leaf, it is inconspicuous so less often seen. The gall of the agamic generation is the Red Pea Gall and this is common on the underside of the Oak leaves. These galls are more likely to be seen than the adult wasps.
The gall can be similar to those caused by other species such as Neuroterus anthracinus and Cynips quercusfolii.
When recording the gall please provide good close ups, and an indication of size. If the gall is on the midrib check for the presence of tissue flaps, or 'saddle' to eliminate Neuroterus anthracinus and confirm that this has been done. Please also cut through a gall and provide a photograph showing the cut through section to establish the width of the gall wall.
Anywhere that the host trees grow
Cynips divisa has a life cycle which encompasses a sexual generation as well as an agamic (all female with no need to mate) generation. The two generations cause different galls in different locations of the Pendunculate Oak trees (see above)
Common and widespread in Britain
It appears to be uncommon in Leicestershire and Rutland but is probably under recorde.
Leicestershire & Rutland Map
Enter a town or village to see local records
Yellow squares = NBN records (all known data)
Coloured circles = NatureSpot records: 2020+ | 2015-2019 | pre-2015