I recently noticed huge numbers of these tiny insects on the stems, buds and undersides of flowers on a prairie sunset heliopsis. They are deep red color and look a little like aphids with longer legs. Most are real tiny with a couple of larger ones included. I was able to squish most of them and it turned my hands red! After I was sure they were gone, they came back a week later. I sprayed them with an insecticide and it got most of them. The plant itself did not appear to be damaged by them but I can't tell yet. Does anyone know what they are?