I wish i had sap sucking spider mites like that on my black Sambucus ;-) lol

Sounds like the usual problem of aphids. Many insecticides available from the garden centre or try diluting washing up liquid into a sprayer and spray them with that.

You can use a systemic insecticide if you like but spray any insecticide in the evening after flying insects have gone, as bees will still be visiting the flowers during the day.