Saw a tiger mosquito for the first time in Boston last fall. Reported it to the state but it is a losing battle and they are steadily establishing residency. Back again this season so a moderately cold winter still did not kill them off. They are extremely annoying as their primary prey are humans and they are very good at biting you without noticing - then comes the itch. Especially in late August into Oct.

https://en.wikipedia.org/wiki/Aedes_albopictus