DIY Mosquito Trap
Here is a non-chemical method of dealing with mosquitos around your deck or place you are, that is cheap and I believe you could also not really kill most of them, but release them after you're done.
Its just a box fan and some window screen. The airflow traps the mosquitos on the screen. While the author uses a 50/50 alcohol water spray to kill them, you could just shut the fan off after and carry the fan out to the garden. Most of the mosquitos should be ok, and they would fly away so bats or other predators could then feed later.
The picture has it being powered with a 12v battery and a power inverter for camping. You could of course just use an extension cord at home.