Question From: K. Pidde - Howard Lake, Minnesota, United States
Q: I have had three willow trees that have died in the last three years. (one each year). This year my oldest willow tree (10 yrs old) was showing the same conditions of the trees from previous years. It toppled over in the wind today and I noticed that there were a lot of little black beetle like bugs on it. Can you tell me what they are? And how to prevent them from spreading? Do I need to be concerned that they will spread to other types of trees? I have maples, ash, dogwood, lilac, and assorted fir trees. The conditions that I noticed the trees in before they died are: leaves turn yellow with black tips and they curl then fall off, bark starts to come off the trunk at the base and white clumps of what looks like spider sacks on the underside of the branches. The branches die soon after they appear. I talked with a Horticulturist at our county fair and she had no idea what could be causing this problem. Your help in this matter would be greatly appreciated.
A: Sounds like willow blight. These diseases are plant specific to willows and will not spread to your other trees. The bugs are willow leaf beetles. If the trees are small you can spray them with Bio-neem. If they are large it would be best to have a professional treat them. To find a certified arborist in your area go to www.tcia.org. Best And Happy Yardening, Nancy