They'll have some use.
Get one of those bands.
I'm one of the lucky ones with skin, I don't burn, I'm as brown as now as what I'll be at the end of summer & I don't get bitten by mosquitos at all.
Charlotte my best friend however gets burnt if the forecast is going to be sunny & mosquitos, well if theres one somewhere within 200km of her, she'll be bitten.
When we went to Asia (KL, Thailand (Koh Samui, Bangkok & Kanchanaburi which is on the river Kwai), Singapore, Bali, Gigi T) in March Air Asia (cannot recommend them enough and $99 flights to Bali) were selling those bands. She got 2, however 1 lasted the whole month long trip, she didn't get bitten once.
I say give one of them a try