> Yes to everything but "the climate is not optimal". The climate was not optimal. I expect this year's weather in most of Europe must have been pretty spectacular for mosquitoes.

You'd think that, but anecdotally there was much fewer this year in Germany than previous years.

At least where I live most of the places where they'd have usually spawned (wetlands) have dried up and shrunk considerably. So really the hot weather made it a worse year for mosquitos.