Cherry Tree Woes

Sazz101

Please could someone advise on what is wrong with this Cherry? It has flowered well two years in a row, but then this happens and no fruit. Thanks in advance. 

vicandlee1

Could be black cherry aphids , had a small tree plastered in them last year that ended up looking like that.

Sazz101

Thanks @vicandlee1. Will have a look for them!