Barklice

The webbing on this oak tree may look very dramatic, but it is not a problem - it is caused by barklice.  Barklice are small tree-dwelling insects that feed on pollen, mold, lichens, algae and dead insects and plant material.  They may go unnoticed until they produce this large web.

They are not harmful to plants or animals - they may even be considered beneficial by some, eating things that grow on the trees.  There is no need to do anything about them, unless you think the web is unsightly.  In that case, you can use a high-pressure stream of water to remove the web from the tree.

For more information see the Clemson Cooperative Extension fact sheet, HGIC 2365 Barklice.