in the summer of 2011, an invasion of "culex molestus" appeared on the upper west side in the borough of manhattan, new york city. the mosquito is well known for being commonly found in sewers of new york and thriving throughout the year feeding on humans. residents of older brownstones found the mosquitoes coming from the underground into basements and then through air vents and other openings into their homes. the city government did not make this infestation of the pest a top priority because they tested negative for west nile virus and because of the high cost of mosquito control.