A small, narrow leaf hopper in the sub-family Typhlocybinae, usually associated with Beech.  Very variable in coloration including a very distinctive brick-red; also bright yellow, pale yellow or whitish.  Occasionally the apex of the forewing is greyish or smoky, and there may be darker streaks on the forewings.   The host plant assists ID, and dissection of male parameres or female ovipositor should confirm it.

The yellow or whitish colour forms are very similar to other Typhlocybinae leafhoppers on trees

yellow etc - males brick red

Good photos of specimen; dissection of yellow/whitish colour forms.  You must note the host species of tree

Usually on Beech trees: plantations, gardens, parkland, churchyards and cemeteries

Common - ref. Auchenorrhyncha UK checklist 2021.

Occasional; few records, but almost certainly under-recorded. Yellow and pale forms, rarely brick-red, present on many Beech trees (including Copper Beech) sampled in early September 2025, sometimes in large numbers. 

https://www.britishbugs.org.uk/homoptera/Cicadellidae/Fagocyba_cruenta.html