I carry a set of the mesh tops/bottoms. Have used them more than once. I treat them with Permethrin before a trip. I believe this will help with the mosquito's, at least better than untreated ones.

MP mentioned the wide brim hat with Permethrin vs a baseball cap.
I use a combo of the two. I wear nylon mesh ventilated baseball cap, with a sun cape I made out of a Bug Off brand handkerchief. I sewed a button on one corner, and a small elastic ring like the ladies use to tie up their ponytails. I wear it like a doo-rag. Then put the hat on. The cape keeps the sun and bugs out of my neck and ears, and protects the top of my head if a bug gets thru the hats mesh areas. I treat all my exterior clothes with the Permethrin before a trip. Unless your adamant about not using chemicals, you won't be disappointed with it.

I tried the Off Clip on bug device in my recent car camping/fishing trip.  Every night about 1/2 hour after sun went down, the skeeters came out in force for an hour or so. Sitting around fire enjoying a few cold one's, the little battery bug repel-er worked very well. There wasn't a stiff breeze, but since a breeze would of helped with the bugs, I thought it was a good investment. If your sensitive too bug bites, all or a combo of the items mentioned might be the ticket for you.

The extra weight while negligible is off-set by the lighter weight clothes  you need during the really buggy seasons.