Are there mosquitoes in Gran Canaria? Yes – no risk of diseases. Hot sun all year round has one downside – winter is never cold enough to get rid of mosquitoes! These mosquitoes are most active in the evening.
Do you need bug spray for Spain?
In any case, Barcelona does not have a "mosquito problem" and generally you would be fine – you just may be subject to the odd mosquito bite in the warmest months if you are unlucky and for a few euros you can protect yourself against this possibility by purchasing a low-cost plug-in electric mosquito killer.