My daughters are allergic to most insect bites and i was advised by aGP/herbalist to use vinegar(cider) and
/or a slice of raw tomato rubbed over the bite. Apparently the acid content in both is the same;the effect to cool,sooth and neutralize the injected alkaline(bite) ..
I have been among mosquitoes so bad that I would work outside with a smudge can....a tin can with holes in the sides and a wire handle with a fine chain; into which I'd get something smoldering, kind of like a bee smoker. I would swing it around me and then set it down so that I'd be mostly standing in the plume of smoke. Tedious to keep up with, sometimes problematic for breathing, and dangerous in dry conditions, but pretty effective against mosquitoes and gnats, at least.