The flowers may be Helianthus. There are lots of yellow flowered members of the Asteraceae family.

There are red mites.
If that is what you have, try a blast with the hose to knock them off. Mites usually do quite well in dry , hot weather.

Here is a link that might be useful: red mites

How about giving us a picture of the critters? I rather doubt that they are mites, since those guys are practically microscopic. But there are plenty of other possibilities.

Yep. Some aphids are bright red, too.

Do they look like this?

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If so, then they're red aphids. They are frequent pests on my Heliopsis. I hit them with the hose. I've tried insecticidal soap and isopropol alcohol on them and they barely put a dent in them. The hose gets rid of all of them :-)

BP

Uroleucon rudbeckiae, a red aphid, on a Helianthus.

Joe