Eupteryx decemnotata

Length 2 to 3 mm, associated with Sage.  Identification of Eupteryx species can be difficult and requires careful examination of markings on vertex, pronotum and forewings.  A small pale yellowish-green leafhopper with brown-ringed cells in the forewings.  There are 4 small marks on the edge of the vertex ('nose') and 2 marks behind, which are of variable size and  may be fused, and 4 more spots on the face, making a total of 10 spots on the head.  

Eupteryx melissae, also on Sage, is slightly larger and has fewer spots on vertex and face. 

Good quality photographs from side, top down and face to show all spots.

Sage

Adult: May to October.

May overwinter.

First recorded from the London area in 2002 (ref.: British Bugs webpage, link below).

Uncommon

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