On Tuesday night, I, along with the people surrounding me, were bitten by mosquitoes while watching the first Fantasmic show. We were sitting in the top three rows of the Pocahontas section. DD, a Fant performer, applies insect repellant before every show.
Last night, she was bitten while walking through Fantasyland so everyone in our group stopped to apply Off using the wipes. I would advise taking the spray or wipes with you.