Here's one article that says that bands reduce but don't eliminate bites. The effect is local to the band, so your head and neck are vulnerable.
https://cameronwebb.wordpress.com/2013/11/25/do-mosquito-repellent-wrist-bands-work/
I hate DEET, and have seen it destroy eyeglasses and plastic covers on binoculars. But the nasty stuff is the most effective. I use DEET in stick form so I don't get it on my fingers. I apply DEET to my ears and along my hairline. I combine citronella with sunscreen cream for my face and neck, and apply it frequently. To complete the protection, I wear long sleeves, and keep my trousers tucked into my socks.
The worst mosquitoes I've ever seen were in central Alaska and the Everglades. Nothing in the Amazon compares. Almost as bad are the biting black flies in Maine, New Brunswick and Quebec. In these cases, a head net worn over your wide brim hat is the best, maybe only, solution.