I meant.... Yellow powdery substance on clematis vines. Are they bugs?

Something that looks powdery is often a mildew - associated with the soil being too dry around the plants' rootball.
These are such thirsty plants that the base of the rootball will dry out very quickly - use the hosepipe on a slow trickle for 10 minutes each watering session, each week, (more if you're in a hot State) because a watering can won't be enough.

Could also be rust, that looks yellowish orange and powdery - otherwise, just pollen dust?