What can I do against my rhododendron buds turning black?

Garden Experts
I have many rhododendron plants. Is there an effective medium against the occurrence of buds which turn brown and then black?

The GARDENA gardening expert

Your rhododendrons were obviously attacked last year by the rhododendron cicada, as a result of which the young buds were infected with a fungi which caused them to die off. The cicadas appear around June, which is why it is necessary to combat them then if necessary. The preparation Kiron by Cheminova is currently certified for the control of cicadas in house and small gardens.

Image: © Aleksey Stemmer - Fotolia