Thank you for your information.

My garden is at the rooftop of an apartment block in the tropics ( temp
being above 30 deg C with humidity about 90%) with almost 12 hours sunlight
everyday.
The plants are in pots ( some were re-potted) and placed on wooden stands
meant for potted plants.

I had tried using the Yates Rosegun Black Spot and Insect Killer. In any
case, do you think by cutting off all the leaves and shoots off all the rose
plants that I have could put a stop on this infestation?

I shall also do a google search. Any starting leads will be appreciated.
Thank you.

Regards,
SC Yap