Question
Japanese Maple bumps
I found white bumps on the bark and some limbs of an otherwise healthy Japanese Maple. When I removed them by hand, they were squishy and some left a spot on the bark where they had been. Is it a fungus or an insect?
Thanks in advance!
AnswerLeigh:
Thanks so much for the image. This is an insect called a wax scale. We see these common on holly bushes. This insect makes it's "living" as a sucking type of insect. Enough of them can debilitate the plant. The babies are called "crawlers" and are produced under the white cap that you see and craw out, settle in and usually don't move again. If you have just a few, you can hand remove them or squash them. If you have a lot on the tree, there is an insecticide that you can mix w/water and apply to the soil. It is picked up by the tree through the roots. It is called BAYER ADVANCED GARDEN TREE AND SHRUB INSECT CONTROL. (It is expensive). There are other insecticides that can be sprayed on the tree. Talk to your nursery or greenhouse professional for suggestions. Keep in mind that even if the scale is killed by the insecticide, often it does not fall off the tree- so you will have to keep an eye out for whether or not new ones form. Be sure to always read the instructions on the insecticide containers. Sometimes, but rare, these materials may cause injury on particular trees.
Regards
Steve
