Plug in mosquito zapper for my bedroom

The zapper won’t work if you leave the windows open ime

That's true, Maryeliza, the window needs to be shut.

What about spraying yourself with Jungle formula mozzy repellent before bed - if you are desperate enough. Or spray the room with fly killer in the morning and keep the curtains closed when you have the light on.

Don’t do as we did. One of our first abroad family holidays was to Sidari in Corfu...major mosquitos. We bought a spray at a local shop, sprayed ourselves each evening and had no problems. When we tried to purchase a replacement the shopkeeper was horrified as unwittingly we had been using the room spray version.

Buy some fine net or butter muslin, cut a piece and sellotape it over the open window. It may make it more fiddly to then close the window, but it is worth it.

We caravanned in the West of Scotland in a heat wave and were sleeping right under the open window. Closing it turned the van into a little metal oven. Leaving it open meant the insects were all popping in all night for a snack. This was before caravan windows had mesh screens. The answer was a trip to a big town with a fabric shop and some DIY mozzie/midge proofing.

You can buy the mesh and cut it to fit your window. The kit comes with Velcro to attach it to your frame. Sold at Lakeland and on Amazon. I have used it for years!

I have a Geranium Citronelle in my bedroom window and I cut a few leaves and put them in water at the side of my bed. I have not had a mozzie bite since I started doing it 2 years ago.
They survive the winter in a sunny corner of my garden room too. They smell nice too fresh and Lemony.

As per Elegran and Teacheranne above, make some mesh covered frames to fit your window. We had them in France - husband made lightweight wooden frames to measure, then tacked on the specially fine mesh.