Yesterday these were all over a quince, where I haven't seen anything before. So, I sprayed the bugs with Safer soap. This morning there were a lot of little black dots which I guessed were dead bugs. This evening, more of them.

Whatever these are, is the answer keep spraying? More complication, we are in the scattered thunderstorm time of year and I can't tell if it is going to rain anytime soon. This picture was taken in the rain, and I assume it is a waste to spray when it is raining. It didn't rain yesterday, so the spray was on for almost 24 hours.

They look like regular aphids.

I do not know safer soap. What I find works wonders is a spay cannister with a spoon of soap (I use dishwashing liquid) and a shot of spiritus/rubbing alcohol.
There is no waiting time: They die immediately. And as it is no poson in the common sense of the words, there are no longer lasting environmental effects.

Safer soap is sort of like that, with some kind of potassium compound that kills them on contact, but I don't know how fast. I don't think there is any kind of environmental impact, but I am not sure. I will try the alcohol based solution, simply to save the trouble of going to get more Safer soap all the time. Killing immediately would be good during the scattered thunderstorms period.

Ha. I should have said the alcohol based solution solution.