Big hello to all.

My name is Phil. I live in New England and have been growing (learning to) tomatoes and leaf lettuce in containers. This is my 2nd year. Last year 4 tomato plants, 3 indeterminate and 1 determinate,10 varieties of lettuce, all survived my newbie efforts.
This year I tried a new soil mix with potting soil, sphagnum moss, and sterilized sand. Last year was heavy garden soil (but worked). I have 5 indeterminates and 1 determinate going. One indeterminate is from cuttings from a Better Boy that grew extra stems from the soil after purchase of the mature seedlings. I'm also trying a couple of new leaf lettuce varieties; Lolla Rosa and Baby Red in addition to a mix and Black Seeded Simpson.
I had no critters on my plants last year, but this year I've been overrun with Aphids (I think). I found hundreds of what looks like tiny white skeletal remains of Aphid nymphs, but I'm not sure, on my tomato plants. I've not been able to find any photos to positively identify them. I can see them clearly with a 10 power loupe and the bodies are motionless, slender, no wings, and longish tentacle like legs. They can be brushed off, but seem to stick pretty well with their feet.
If you can help identify them I'd appreciate it. I gave the plants a thorough dousing with Spectracide Once & Done Garden Insect spray, but we had heavy rain about 6 hours later.
Today, I can see hardly any left on the tomato plants. This morning I pruned all the damage off them.
So far, my tomato count is up to 110ish in various stages of growth on 5 of the plants. I'm hoping the pruning doesn't inhibit my harvest!!!