Question
Hi I planted 2 Swedish columer aspens in my back yard beside my deck. They have been doing really well for the last 2 yrs until august when i noticed the one has ants on it and now hornets are all over it. I don't know why? The top looks good but the bottom leaves are all full of holes. What should I do. thanks for your time

Answer
Ants and wasps will be attracted to a substance called honeydew. There are insects that suck the plant juices from the plant and secrete a substance called honeydew-this is high in sugar content and sticky. If the foliage is sticky and appears wet this is what the problem is. I would treat the trees with an insecticide called Orthene. This is sprayed on the foliage and twigs and will kill the aphids and/or scale insect that are sucking the juices. IF the tree is too large to reach with the spray use a insecticide called Bayer Advanced Tree and Shrub Insect control, This is applied  to the soil around the tree and the roots will take it to the foliage and kill the insect as they feed. Here is a web link to this product. Check with your local nursery for these products. http://www.bayeradvanced.com/product/Tree-Shrub-Insect-Control/concentrate.html