I have a new unidentifyable pest. This one has made it’s home on one of my Callistamons. I’ve cut off the affected leaves and that seems to have gotten rid of it for now but I’m curious to know what it is. They look like dark balls all bunched together and they don’t move. Any ideas? I’m unfortunately learning lots of different pests in my first garden 😦

Looks like aphids but cannot tell without a close up.
Aphids.