I want backyard to be bug-free, so my guest and can Bar-b-Que
Patio fans is the fast simple method. Gather any fans you have, or borrow or rent from a party rental supply house. The bugs don't care for the breeze and stay away. Citronella candles help too.
Here is a citronella candle tutorial
Also, spray the yard and the porch/ deck with this right before the event https://familyfocusblog.com/make-natural-insect-repellent-recipe/
This is tough, you can treat the ground, but not the air.
Citronella candles or tiki torches.
Spray with Listerine in the air about 30 minutes prior to keep them away.
You can try a few of these ideas'