The mite Phyllocoptruta coryli causes galls to form in the catkins of Hazel. There are two very similar galls on Hazel catkins. Phyllocoptruta coryli contains mites (which are very small and may need magnification under a microscope to see them), whereas Contarinia coryli contains white jumping cecid larvae. To distinguish between these two - the galls must be opened to confirm whether mites or gall midge larvae are present. Images appearing in a red box may well be Phyllocoptruta coryli but the contents of the gall were not examined as required above.

Contarinia coryli (a gall midge)

Gall Adult

Catkin must be opened and mites photographed to complete a record - Phyllocoptruta coryli mites are very small and can only be seen under high magnification

Anywhere that Hazel catkins are found.

Galls may be seen at any time that catkins are present on Hazel.

Probably widespread and fairly frequent, but not well recorded in Britain.

Status in Leicestershire and Rutland not known.