Yes, they're aphids.

Direct hits with insecticidal soap works as does squishing.

Thanks, I have some insecticidal soap and will give that a go.
Bruce

Aspens are aphid magnets. If you spray your trees thoroughly with a dormant oil in the winter, you can smother the overwintering eggs hidden in any little nooks and crannies. Horticultural oils do a pretty good job of controlling aphids at any time of year but you need to be careful of the temperature restrictions when the trees are in full foliage.

There are well over 1000 aphid species just in the US, thus there are many different colors, sizes, and other characteristics.

Do the different aphid species attack only certain plants? Or do I have to worry about aphids on my Aspen migrating to my Hot Peppers as Hot Peppers tend to attract Aphids also.
Bruce

There ARE aphids that are specific to Aspen and cottonwood and willows (all in the same family). I believe that your aphid is one that will be found on only those plants. There are other examples of certain aphids being specific to their host...such as the pretty (I think) milkweed/oleander aphid. Those aphids are bright yellow/orange with black stockings, lol.

Others can be found where ever they darned well want, it seems. You probably see pink, green, or gray colored aphids on your peppers.

Yes, I have see quite a rainbow on my peppers and roses. Thanks everyone for the help, information and advice.
Bruce