The MothNMC is a small and annoying creature as their attacks can Blind Aya, making it impossible to target the larger and more powerful enemies they are often encountered with until it wears off or Metabolism/Penicillin are used. Their own attacks kill them and deal little damage so if DARKNESS can be resisted or easily healed, Moths are not a danger.
Given their lack of HP, any weapon suitable for taking out larger numbers of weaker targets will work well, including automatic weapons and Buckshot. Combat Light was quickly dispose of larger number of Moths. Plasma and Necrosis would also work in a pinch.