Aedes japonicus japonicus was collected via gravid trapping in Wisconsin in the summers of 2004 and 2005 at Fort McCoy, Monroe County. Subsequently, in the summer of 2007, Ae. japonicus was captured in a human landing catch in Dane County, Madison, WI. Additional collections were made at this site in the spring of 2008. Invasion is in progress, but significant population increases have not yet been confirmed.