I've read that some primates, Homo Sapiens are quite invasive too: Possibly fought all others from the Homo line to extinction, destroyed 80% percent of Earth ecosystems and setting the stage for a pretty swift mass extinction event, possibly before the end of the century, and perhaps much before according to latest literature.

Oh yeah and are in a good way to double their planet's atmosphere CO2 content, which regulates the latter's temperature, making the extinction event even swifter. A definite sign of intelligence.

But you are correct, mosquitos are terrible beings, the second most deadly living creatures on this planet to be precise.