I don't understand why they bothering with wetlands. As far as I know tiger mosquitoes breed in tiny pools of water. In a natural setting this means cups formed by leaves in jungles. In Barcelona, beer cans, ashtrays, plant pots on terraces. I believe they have now reached my own Poble Sec, though I have yet to meet one of their accursed number.
I suspect this spraying is nothing to do with tigers and is just a general spraying programme which has been going on since the 1950s. As a self-appointed expert who doesn't really have a clue, I shall endeavour to find out more.
Incidentally, as El Prat was one of the last places in Spain to rid itself of malaria in the early 1960s, the expertise has remained in the area, and local specialists are now considered experts at a world level on mosquito eradication.