Help! What is this pest?
Novice gardener here who has inherited a well-stocked garden! At the back of my garden is a rhododendron which ispretty big and has white flowers (only been here a few months so I've never seen it flower, although the estate agents pics show it flowering last summer!). There have been dozens of flower buds on it for a good 4-6 weeks now but not one has opened.
I've noticed that the leaves are covered in black 'soot', but as we're next to a busy road I put it down to road dirt (although it doesn't affect any of my other plants). Today upon closer inspection I've noticed hundreds of little creatures on the stalks of the shrub (nothing on the leaves or the flowers). They are squidgy and slug-like, not hard like a beetle. They are flatter than a slug and are less than 5mm long.
Can anyone help me identify what these are and how to get rid of them? I have pets and a toddler so preferably nothing too toxic, although I can keep them away if that's what's required. It's a big bush and it's infested so I'd rather not have to scrape them all off by hand!
Sorry that's so long, thanks in advance!