You're telling us you have more pests in your back yard than in your front yard? Also: Would passersby picking your fruit be an issue?
There is a terrific product that few seem to know about: "Tanglefoot." If you're worried about squirrels or other "pests" harvesting your fruit, then don't plant the trees where squirrels and rats and Opossums can access the trees by either dropping down atop the trees or climbing up into them.
Tanglefoot will keep all sorts of "pests," including scale, aphids, ants out of your trees --- anything that will have to climb up the trunk of the tree.
Lemons (the fruit thereof) ---- I have never had a problem with any "pests." Tangerines, though ----- everybody loves a good tangerine.