Julie, you may have scales.* They have a hard shell like a beetle but arean't shaped like a beetle.* They come in different colors such as tan, brown, creme, pink and black.* Is this what you see?
Usually Neem oil will work well on these if insecticidal soap doesn't.*
Maren's idea of soaking the soil with soapy water is a good one, but I wouldn't recommend detergent as it can be too strong for the plants and has more phosphate residue then soap.* You can make your own insecticidal soap.
When weeding, the best way to make sure you are removing a weed and not a valuable plant is to pull on it. If it comes out of the ground easily, it is a valuable plant.