ScienceDaily (Feb. 8, 2012) – A species of mosquito not seen in the UK since 1945 has been discovered breeding in the country. Populations of the mosquito, found across mainland Europe and known only by its Latin name Culex modestus, were recorded at sites in the marshes of north Kent and south Essex in 2010 and 2011.
See the article here:
Continental Mosquito With ‘Vector’ Potential Found Breeding in UK After 60 Year Absence