Question
Thanks Jim - while wtg. for your response I plugged the hole with vaseline, duct taped over it & then spread the duct tape with vaseline. The borers stayed in, I am assuming they will suffocate & die. Is this correct?

Also - I have noticed a problem with my white pine trees (this is the summer of bugs, geez!) in that there are colonies of ants living in them & the trunks & needles close to it are covered in a black excretion (almost looks like they burned). The trees are slowly dying off, whether its from this or not, I don't know. Any suggestions.

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Followup To
Question -
I have a Camelot Dwarf Crabapple tree & live in Northeast PA. Something is eating the tree from the inside out. There is a small entry hole on the trunk & small brownish/red "pellets" being pushed out of the hole. The area surrounding the hole is soft as if they are destroying the trunk from the inside. I did some research & thought I had fruit boring worms & the suggestion was to paint over the hole to suffocate them, but they ate their way out. I also put duct tape over the hole which they also ate their way out of. Please help.
Answer -
Sounds like a borer has infested your tree. I would recommend spraying an insecticide on the trunk. This spray will soak into the trunk and kill the insects in the wood. Check with your local garden type store for an insecticide for borers and follow the directions on the bottle.  

Answer
I really do not know if the "duct tape and vaseline" will work. I think you will probabally have to spray the trunk with an insecticide--watch and wait and if needed you can spray.
The other problem sounds like aphids--these a small insects that suck the sap out of leaves and small twigs of plants. They excrete a substance called "honeydew". A fungus will grow on the honeydew and this is what you see as black. Control the aphids and you control the black sooty fungus. Spray the foliage and trunk with an insecticide for aphids--check with your local garden type store for an insecticide for aphids used in your area. (a Systemic type would be best).