There used to be a myth that mosquitoes are only a problem in summertime. That is not true, these insects will now breed all year and because there are more likely to be puddles in autumn and winter, they take advantage of that fact. Certainly, the breeding cycle is slower during cold weather and a sudden drop in temperature will temporarily halt their activity but they soon recover.
The other problem we face is that mosquitoes have developed an immunity to many of the sprays and creams that once deterred them. As I said in a previous item, DEET used to be very effective in warding off mosquitoes but the insects have gradually learnt to tolerate it.
We need to find ever more resourceful ways to control the spread of these insects. In Torrevieja they have introduced bats, one of the few natural predators of mosquitoes but of course it takes time to develop a colony of sufficient size to control a plague of insects.