Yes, it may spider mite. The thing is that they appear on the underside of the leaf. Anyway, if thee is fine webbing on the plant then leatherbacks opinion is present. Now, getting rid of them....... They can adapt to pesticides but is unlikely. First of all the despise humidity so if it is them then get it humid. Another thing may be a pesticide (systematic). I may be wrong with the cure info, i do not have much experience with pests. Good luck