I think I have mealy bugs on a shrub that is part of a hedge of shrubs in...
I think I have mealy bugs on a shrub that is part of a hedge of shrubs in front of my house. They have just about killed the first shrub and seem to be invading the rest as well. The top of the leaves are black and sooty and the bottom has white long kind of rectangular white cottony looking stuff and I have seen some small white bugs. What can I do to save the rest of the hedge -- I used a power washer this morning to try to get rid of the bugs, but I don't know what else to do.
We do not think you have mealy bugs on your shrub most likely what it has is cottony camellia scale. It would be most helpful to know what type of shrub you have. Cottony camellia scale is found on holly, yew, euonymus, camellia, and a few other types of shrubs. For additional information and photos see the following information on the 'plant diagnostic' section of our website, http://plantdiagnostics.umd.edu/level3.cfm?causeID=47
The black sooty coating you are seeing is called sooty mold. It is a fungus that grows on top of the honeydew that this scale insect produces. Control using a horticultural oil which should be used now because the crawlers of the insect are present. But, watch the temperatures do not spray above 85 degrees or use according to the label directions. A dormant oil spray in late fall or very early spring will help reduce some of the overwintering insects.