Figure 1

A) North-west Europe, showing locations where Culex modestus populations were detected in this study (white circles), the location of Cx. modestus identified in southern England in 1944-5 (white triangle), and recent records from Europe (black triangles; Francis Schaffner, personal communication and articles cited here). All of these recent records date from the period 2004-2009 with the exception of the two northernmost French records, which date from 1995 and 1998. B) Thames Estuary area, showing locations where Cx. modestus populations were detected in 2010 (white circles) and the locations of international shipping terminals (black squares). To give an indication of the size of the port, black squares are proportional to number of ships arriving during May 2011: small squares 1-25 ships; medium squares 26-75 ships; large squares 75-165 ships. Urban and semi-urban areas, as classified by the United Kingdom Land Cover Map 2000, are coloured dark grey.