Any suggestions how to get this tree on the ground safely?

[2manyrocks]

If you don't have to cut the tree right now, you could wait until cool temperatures to drop it when the wasps become inactive.

A heavy dose of Dawn dishwashing detergent in a garden sprayer will kill wasps, but since you don't know where they are, there appear to be a lot of them, and you have allergy concerns, it might be better to wait until temps drop if you can.