Disease???

[Andy D]

One of my Japanese maples has little greenish black bumps(that can be rubbed off) on the underside of some of the leaves. what is it and how do i get rid of it. please help!!!

[Gnome]

Andy,

little bumps that can be rubbed off sounds like scale insects. They might also be Aphids. If you have a hand lens you should be able to identify them. Aphids are obviously insects while scale are immobile lumps.

Your tree will be losing it's leaves soon. Perhaps you need not do anything other than destroy the fallen leaves so they do not reinfect your plant next spring. You could also try a dormant oil spray to kill any possible eggs that may be present.

Norm

[nyther]

This sounds like scale. A bug that creates a hard shell around itself for protection. You can use an insecticidal soap or neem oil. I had many on a fukien tea and used rubbing alcohol on a swap and dabbed them with the alcohol. This will kill them instantly. Then I used insecticidal soap once a week until they were gone. This is necessary to kill the eggs and young scale that are hosting on bonsai. Hope this helps.

Ken

[Andy D]

Thank you very much that helps a lot