Question
I have a Christmas tree growing in my garden which was well established when I moved into the property 2 years ago.  I recently noticed black wet patches on the ground underneath the lower branches.  When I looked at the branches, some had turned black and sticky.  I noticed there were a lot of ladybirds on the tree and on closer inspection, the tree branches are covered in what appear to be black beetles.  Now the tree is covered in wasps and some of the needles have turned brown.

The only thing I have done so far is spray the tree with soapy water.

Should I be just leaving the insects alone to let nature take its course or should I be doing something else?

Thank you.

Answer
The tree is infested with a sucking type insect. Either aphids or scales. Both will suck the plant juices and secrete a substance called honeydew. A black sooty mold will grow on the honeydew. The honeydew is high in sugar content and sticky and attracts ants and bees.

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 pick it up and carry it to the stems and foliage and when the insects suck the plant juices they are killed. Check with your local garden type store for this product. here is a web link to more information on this product.

http://www.bayeradvanced.com/tree-shrub-care/products/12-month-tree-shrub-insect...