Question
We're seeing a swarm of bees and flies on our Japanese Maple tree.
Is this an indication of some disease or infestation? How can we cure it? The tree seems to be otherwise healthy.

Answer
It could be an infestation of aphids or scale insects. These insects suck the plant juices from the tree and secrete a substance called honeydew which is high in sugar content and sticky. If the foliage is sticky and /or is wet looking this is the problem. The bees are coming to harvest the honeydew. Treat the tree with an insecticide called Bayer Advanced tree and Shrub Insect control. This is applied to the soil around the tree and the roots will carry the insecticide to the foliage and twigs and when the inset sucks the plant juice they are killed. The bees will go away when the honeydew is no longer present. IF the tree is small enough to spray all the foliage you can spray the tree with an insecticide called Orthene --this will also kill the insects. Check with your local nursery for these products. Here is a web link to the Bayer product.

http://www.bayeradvanced.com/product/Tree-Shrub-Insect-Control/concentrate.html