18 UK species. This family of psyllids is characterised by the 3 main veins in the forewing all arising from the same point. Some species cause galls to form on host plants.
Valerian Psyllid Trioza centranthi
The reddish leaf rolls on Red Valerian (Centranthus ruber) are quite distinctive. These galls are caused by the nymphs of the bug Trioza centranthi.