Leech-like creature on Hawthorn leaf

Leech-like creature on Hawthorn leaf

Observation - Leech-like creature on Hawthorn leaf. Description: This is the first one of these that I've found that has been big enough to get a decent photo of - hopefully someone can ID it for me please? It looks like it has bristly hairs/feet under its raised area..

This is the first one of these that I've found that has been big enough to get a decent photo of - hopefully someone can ID it for me please? It looks like it has bristly hairs/feet under its raised area..