Very strange insect!
Do you know what kind of insect this is? It was on the underside of a leaf in the herb garden, along with spider mites. What is the purpose of all the white material it made? It's not webbing, I'm not sure how to describe it. Thanks for your help!
Montgomery County Maryland
This looks like a planthopper. They are not damaging and do not need control.
The white material is a type of waxy substance that they cover their bodies with, and often leave behind.
Here is a page from our website on Planthoppers: