Hi @amique393,
A warm welcome to the Bunnings Workshop community, it is fantastic to have you with us.
It looks like you are dealing with a scale insect infestation.
I'd suggest you physically scrape away as much of the insects and waxy deposits as possible, then apply a Yates Ready To Use Scale Gun Insect Pest Killer.
It contains white oil, which will help to dissolve the waxy deposits and pyrethrum, which will kill the insects.
Repeat this process weekly until the scale insects are managed.
Check out How To Maintain Healthy Roses for some further tips to get the most out of your roses.
Let me know what you think and if you have further questions, please don't hesitate to ask.
Jacob
