Bug zappers attract bugs and then kill them with electricity. These are effective, but they can be noisy and potentially emit a smell if enough bugs are killed.
Bugs are attracted to the emission of heat and waves from light bulbs, so installing cooler LED bulbs will instantly reduce the amount of bugs who find your porch or balcony light appealing.
Install an outdoor ceiling fan on your balcony or porch–if you have the proper type of overhang for it. Circulating air will keep bugs away while also keeping the area cool and comfortable.
This includes but is not limited to: standing water, leftover food, certain types of smells such as floral smells, and certain plants.
Install a light designed to turn on with a motion sensor. This will help prevent bugs from accumulating near a light that is always turned on.