Q: The other day I was laying pine straw in one of my flower beds and I noticed tons of yellow jackets hanging around one side of my loropetalum.

I looked up to the 20ft Nuttall oak that hangs over it and noticed they were buzzing around it too. I noticed little critters all over a couple of the woody branches of the oak tree. Could these be aphids? Will they do my tree any harm?

A: My entomologist friend Jule-Lynne Macie at first thought they were treehoppers…but on closer examination decided they must be aphids. That would explain why so many honeydew-feeding insects were hovering about.

I think you are seeing giant bark aphids, Longistigma caryae.

These creatures don’t usually build up such a large population but long warm autumn weather allows them to breed and become noticeable. They don’t cause much harm to a tree but the honeydew they secrete brings the stinging insects you noticed.

I think the best treatment is to blast them out with a water hose.

see

http://entnemdept.ufl.edu/creatures/trees/giant_bark_aphid.htm