Giant Bark Aphid – Identification
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.