May 19, 2014 - 12:04 PM
The problem with Pyrethrum is that it is a very SHORT LIVED insecticide, maybe 15 minutes once applied. So there is NO residual. This greatly reduces the chances that you will get control, so maybe this is what WebMD was referring to.
The best insecticides for mites are true MITICIDES such as Bifenthrin. Other insecticides such as Premise, Merit, or Dominion are also effective.
The key to controlling mites is to treat the areas such as plants where they live. Since there are many different species of mites, I would have to know which mite you are dealing with to give you any specifics.